Scandinavian Cardiovascular Journal, 2014; 48: 41–46
ORIGINAL ARTICLE
Coronary sinus cannulation with a steerable catheter during biventricular device implantation*
LINGWEI WANG, SHIWEN YUAN, RASMUS BORGQUIST, CARL-JOHAN HÖIJER & JOHAN BRANDT Department of Arrhythmias, Skane University Hospital, Lund University, Lund, Sweden
Abstract Objectives. To determine whether a steerable catheter with electrogram guidance (CS-assist group) could facilitate access to the coronary sinus (CS) during cardiac resynchronization therapy (CRT) implantation. Design. Consecutive patients who underwent CRT implantation were recruited prospectively into the CS-assist group (n ⫽ 81) and compared with those using conventional techniques without an electrogram guidance (conventional group, n ⫽ 101). Results. The CS cannulation success rate was clearly greater in the CS-assist group (100%) than that in the conventional group (95%, p ⬍ 0.05), with significantly shorter mean procedure time (52.6 ⫾ 20.6 min vs. 73.2 ⫾ 40.9 min, p ⬍ 0.01) and fluoroscopy time (3.6 ⫾ 3.2 min vs. 14.2 ⫾ 20.4 min, p ⬍ 0.01). In the five CS cannulation failure cases, mean procedure time (144.0 ⫾ 37.0 min) and fluoroscopy time (57.8 ⫾ 24.8 min) were significantly longer than those in the other patients (61.2 ⫾ 32.3 and 8.2 ⫾ 13.6 min, respectively, n ⫽ 177, both p ⬍ 0.01). Conclusions. Using the steerable catheter with real-time electrogram guidance, location of and access to the CS is more rapid and successful, which may improve the success of the CRT implantation and may give significant time savings. Key words: cardiac resynchronization therapy, coronary sinus cannulation, electrogram guidance, heart failure
Introduction Heart failure is a major healthcare problem and is associated with both morbidity and mortality (1). Cardiac resynchronization therapy (CRT) is one of the most important therapeutic advances in recent years for drug-refractory, chronic congestive heart failure with electromechanical dyssynchrony; it can improve quality of life and reduce mortality (2). During CRT operations, gaining access to the coronary sinus (CS) can be a challenging and a timeconsuming process. Valves, ridges, and unexpected anatomical changes due to natural or surgical causes can increase the time required to access the CS, and there is a 5–15% failure rate according to clinical reports (3–6). CS cannulation using electrode catheter and electrogram guidance is widely used in electrophysiological laboratories, but not yet in CRT implantation. To our knowledge, there has not been any publication
before concerning the use of a steerable catheter and electrogram guidance during the CRT implantation, though electrophysiology (EP) catheters have been used in clinical practice (7). Recently, a steerable catheter with electrogram guidance (CS-assist catheter) was developed to help gain access to the CS during CRT implantation. In the present study, we aimed to systematically determine the feasibility and efficacy of using the CS-assist catheter in patients undergoing CRT implantation. Material and methods Study population From September 2011 to September 2012, consecutive patients referred to our center for CRT implantation were prospectively recruited into the study (CS-assist group, n ⫽ 81). The results were compared to those of consecutive patients for the
*The paper has been presented at EHRA EUROPACE 2013 in Athens, Greece from 23–26 June 2013 and the 39th International Congress on Electrocardiology in Beijing, China from 8–11 August 2012. Correspondence: Dr Lingwei Wang, Department of Arrhythmias, Skane University Hospital, Lund University, SE-211 85 Lund, Sweden. Tel: ⫹ 4646171680. Fax: ⫹ 4646 323574. E-mail: [email protected] (Received 21 October 2013 ; revised 11 December 2013 ; accepted 11 December 2013) ISSN 1401-7431 print/ISSN 1651-2006 online © 2014 Informa Healthcare DOI: 10.3109/14017431.2013.875623
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CRT implantations between January 2010 and September 2011 using conventional techniques (Conventional group, n ⫽ 101) with Terumo, direct lead, or guide wire without electrophysiological catheter and/or real-time electrogram guidance. All the operations were performed by a single operator using the access of the left cephalic and subclavian vein. CRT implantations from the right side and/or those performed by other operators were excluded. The study complied with the Declaration of Helsinki and was approved by the investigational review board at Lund University Hospital, Sweden. The informed consent of the patients had been obtained.
The CS-assist catheter The CS-assist catheter (Bard Electrophysiology Inc.) is designed merely for CRT implantation. It is 6 French with 65-cm usable length and two electrodes at 5-mm spacing on the deflectable tip. Different from the conventional EP diagnostic CS catheter that is 110-cm long with 10 electrodes, the CS-assist catheter gives easier ergonomic manipulation, and its bipolar electrode configuration provides simple mapping capability.
Intracardiac mapping and CS cannulation During the cannulation with the CS-assist catheter, bipolar electrograms were recorded and displayed in real time using an EP Recording System (LabSystem™ PRO, Bard Electrophysiology Inc.). This helped us to identify the location of the catheter (Figure 1). Using the CS-assist catheter with real-time electrogram guidance, we could try the posterior, superior, anterior, or inferior approaches to access the CS. We mostly succeeded in gaining access to the CS from an anterior (ventricular) and inferior approaches, due to the anatomy of the CS and the presence of the Thebesian valve. Using the ventricular approach, we first placed the tip inferiorly in the right ventricle and then bent the catheter tip while rotating it counter-clockwise, that is, we let the tip point inferoposteriorly toward the posterior septum. When the bipolar electrogram changed from a dominant V-deflection to a dominant Adeflection, the catheter was advanced toward the CS ostium posteriorly. If the catheter entered the CS, one could see a dominant A⫺ or balanced A/V-deflections all the time from the recording. These electrogram features were present even when the patient was in atrial fibrillation. If the dominant V-deflections appeared again, it indicated that the catheter was back into the ventricle and that the
Figure 1. Bipolar electrogram (EG) recorded via tip electrodes of the CS-assist catheter together with ECG lead III (III). A: Catheter from right ventricle (RV) to right atrium (RA). Only ventricular deflection and no atrial deflection suggested its right ventricular location. After withdrawal and counter-clockwise rotation, a dominant A-deflection was suddenly seen, suggesting that it had reached the AV junction near the CS ostium. B: At the CS ostium, the catheter was advanced posterolaterally while a dominant A-deflection was still present, indicating that the tip was at or already in the CS ostium; otherwise, a large V-deflection would have appeared. C: The catheter was further advanced laterally without resistance, while a dominant or fairly large A- and V-deflections were present all the time, suggesting that the catheter was deeply in the CS.
above procedures should be repeated. When it was difficult to access the CS ostium, very often it was because of hindrance by the Thebesian valve. Further bending of the catheter at the CS ostium followed by immediate release and advancement of the catheter could help in getting through the Thebesian valve.
Coronary sinus cannulation with a steerable catheter Main parameters and statistical methods In comparing the two groups, CS cannulation success rate, procedure time, and fluoroscopy time were used as the main parameters. In addition, any complications related to the CS cannulation were recorded. Data were reported as mean ⫾ SD (median) if not especially indicated. For statistical analysis of comparisons, non-parametric Wilcoxon–Mann–Whitney test was used for the procedure times and fluoroscopy times and Student’s t test or Chi-square test was used for success rate and clinical data. Differences were considered significant at P values less than 0.05.
43
than that in the conventional group, 73.2 ⫾ 40.9 (65) min, (p ⬍ 0.01). Procedure time in the five CS cannulation failure cases (144.0 ⫾ 37.0 (155) min, n ⫽ 5) was significantly longer than that in the other patients (61.2 ⫾ 32.3 (59) min, n ⫽ 177; p ⬍ 0.01). Fluoroscopy time in the CS-assist group (3.6 ⫾ 3.2 (2.6) min) was significantly shorter than that in the conventional group (14.2 ⫾ 20.4 (7.1) min) (p ⬍ 0.01). Fluoroscopy time in the five CS cannulation failure cases (57.8 ⫾ 24.8 (59.0) min) was significantly longer than that in the rest of the patients (8.2 ⫾ 13.6 (3.9) min, n ⫽ 177; p ⬍ 0.01). Special cases
Results Cannulation success rate We included 182 consecutive patients aged 69.1 ⫾ 12.0 years who received CRT implantations by the same operator. The clinical data are presented in Table I. There were five failures in CS cannulation (5%) in the conventional group (n ⫽ 101), whereas there were no failures in the CS-assist group (n ⫽ 81). Thus, the success rate of CS cannulation was much higher in the CS-assist group (100%) than in the conventional group (95%, p ⬍ 0.05). Of the five CS-cannulation failures, the left ventricular (LV)-lead was placed in the right ventricular outflow tract at the same procedure in three, and the LV-lead placement succeeded later at a second procedure in one. The fifth patient unfortunately died 1.5 months after the first procedure before the scheduled re-operation.
Total procedure time and fluoroscopy time Total procedure time (skin-to-skin) in the CS-assist group, 52.6 ⫾ 20.6 (50) min, was significantly shorter
There were two patients in the CS-assist group in whom CS cannulation had failed in a previous procedure. Case 1 had had CS cannulation failure before (procedure time: 92 min and fluoroscopy time: 40.4 min). In the present procedure (procedure time: 75 min and fluoroscopy time: 6.7 min), we experienced resistance around the CS ostium and succeeded in CS cannulation by further bending the CS-assist catheter at the CS ostium followed by immediate release and advancement of the catheter. The CS sheath could not follow the catheter into the CS, due to resistance around the CS. CS venography showed that the CS sheath was located exactly at the CS ostium and a Thebesian valve covered almost the entire CS ostium (Figure 2), which could have been the reason for the difficulties in performing this procedure and for the failure of the previous one. In Case 2, CS cannulation had failed in a previous procedure with a fluoroscopy time of 60 min. At the present procedure with the CS-assist catheter (procedure time: 35 min and fluoroscopy time: 0.9 min), there was some resistance around the CS ostium when the CS sheath entered the CS along the CS-assist catheter, but it did not affect the process of CS cannulation. There was also a Thebesian valve
Table I. Clinical characteristics. Patient characteristic Age (years) Gender (% male) Ejection fraction (%) NYHA class Coronary artery disease (%) Previous CABG (%) CRT during paroxysmal AF (%) CRT in permanent AF (%) Primary CRT implantation (%) Primary LV lead implant (%)
CS-assist group (n ⫽ 81) 69.2 ⫾ 10.7 74.1 24.1 ⫾ 4.9 2.8 ⫾ 0.5 48.1 23.5 12.3 21.0 79.0 95.1
Conventional group (n ⫽ 101) 69.0 ⫾ 12.2 82.2 25.4 ⫾ 5.9 2.8 ⫾ 0.5 39.6 22.8 13.9 21.8 70.3 95.1
CABG, coronary artery bypass grafting; AF, atrial fibrillation; LV, left ventricular None of differences in the above characteristics were statistically significant between the two groups.
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L. Wang et al. Discussion The CS is the gateway for LV lead placement in CRT (8). CS cannulation is a critical prerequisite for this therapy. The recently developed CS-assist catheter with the real-time electrogram guidance is dedicated for identifying the CS ostium and facilitating the access to the CS during the CRT implantation. To our knowledge, no systematic clinical evaluation of this catheter technique has been published. The present study has shown that using the CS-assist catheter with deflectable tip and intracardiac electrogram guidance, localization, and access to the CS was more rapid and successful, which improved the success of CRT implantation—with significant savings in implantation and fluoroscopy times.
Anatomical aspects Figure 2. CS venography from a 78-year-old man in the CS-assist group (special case no. 1) with chronic atrial fibrillation and CS cannulation failure in a previous procedure. During the venography, there was no leakage of contrast in all superior or posterior approach, while slight leakage was seen anterior and inferior approaches, which was markedly different from the venography findings in most of our patients. This indicates the presence of the Thebesian valve covering the posterior and superior aspects of the CS ostium and explains the difficulties in the CS cannulation— both in the previous and in the current procedures.
covering the CS ostium. The procedure times and fluoroscopy times in these two difficult cases were nevertheless shorter in the present procedure with the CS-assist catheter than in the previous one without the CS-assist catheter. Complications One patient in the conventional group had CS perforation during the LV lead delivery because of an S-shaped narrow curve in the tributary CS vein. Before the perforation, there was obvious resistance. The patient recovered without sequelae after percutaneous pericardial drainage. CRT implantation succeeded two months later. There was also a patient in the CS-assist group who had leakage of contrast into the pericardium during cannulation. This was one of our earliest cases using the CSassist catheter. A stenosis and a valve in the main stem of the CS were detected, and we met resistance at the stenosis when passing the CS sheath at selective CS venography. Slight leakage of contrast into the pericardium was found. Echocardiography did not show any clear pericardial effusion and the patient recovered without further treatment.
The CS ostium is 5–15 mm in diameter and is located on the inferior-posterior interatrial septum, anterior to the Eustachian ridge and valve, and posterior to the tricuspid annulus (9). Like the rest of the cardiac venous system, the CS contains various valves, including the Thebesian valve and Vieussens valve. These valves are sometimes important obstacles, obstructing the CS sheath—and thereby the LV lead—from advancing into the cardiac veins (10). The most common valve is the Thebesian valve at the ostium of the CS (8,11), a caudal remnant of the embryonic sinoatrial valves. This valve can present with variable shape (12). It can be semilunar, fenestrated, or band-shaped (13), and occasionally it causes dynamic obstruction (14). Postmortem studies have found the presence of Thebesian valves in more than 70% of hearts (6). The valve may cover the CS ostium from 0% to 100% (13), and it may be a potentially complicating structure and an obstacle during cannulation of the CS (14). The orientation of the Thebesian valve favors cannulation of the CS from an anterior (ventricular) and inferior approach (11). This could easily be done using the CS-assist catheter, as demonstrated by our special case no. 1. Moreover, Duda and Grzybiak reported a 10% incidence of a Vieussens valve in the lumen of the CS itself (15), with a complete single valve totally dividing the lumen of the CS into two in 1.3% of cases. This can be another problem during the CS cannulation. Use of the CS-assist catheter could help in passing the Vieussens valve, by bending and/or rotation of this catheter. The CS dissection in one of our earliest cases in the CS-assist group probably occurred when trying to pass a Vieussens valve in the main stem of the CS without having enough experience of the equipment. After that, we had two other
Coronary sinus cannulation with a steerable catheter similar cases with a valve in the main stem, and we succeeded with the CS cannulation with the help of the CS-assist catheter in both. One of the pitfalls of CS cannulation is repeatedly entering the right ventricle, without recognizing it from a single fluoroscopic view, before ventricular extra beats were induced. Using the CS-assist catheter with real-time electrogram guidance, one knows all the time whether the catheter tip is in the ventricle or in the atrium—and especially if it is in the posterior A/V junction where the CS ostium is located. With the help of electrogram guidance, the catheter tip never moves away from this area and the chances of entering the CS are considerably greater. In addition to electrogram guidance, the steerable tip of the CS-assist catheter is an appreciable help in getting through the Thebesian and Vieussens valves as described above. Clinical considerations CS cannulation failure is one of the most important factors affecting the success rate of the CRT. The reported failure rate in the CS cannulation ranges from 5 to 15% (3–6), with the most recent data indicating 2.9% failure (16). This is consistent with the general CS cannulation failure in our patients (5 out of 182, 2.7%), whereas there was no failure in our CS-assist group. This shows clearly that the new technique can improve the success rate of CRT by facilitation of CS cannulation. The total average procedure time of CRT has been reported to be between 67 and 167 min and average fluoroscopy times from 18 to 36 min (16– 18), depending on different routines and experience. Our results showed short procedure times and fluoroscopy times in both groups. Nevertheless, the procedure and fluoroscopy times in the CS-assist group were significantly shorter than in the conventional group and in the published clinical data (16–18), suggesting that the CS-assist catheter has a beneficial effect independent of other factors. Among several others, reduced procedure time has been showed to be a factor that is predictive of fewer device-related infections (21). In addition, there has been growing concern regarding the radiation-induced cell injury, malignant diseases, and heritable effects (19,20). In these respects, the reduced fluoroscopy time with CS-assist catheters could reduce the radiation injury to both patients and physicians during the CRT implantation. Coronary vein dissection and perforation are one of the most common complications associated with the insertion of the LV lead during the CRT implantation. The complication rate ranges from 1.9 to 4.6% (21). Kautzner et al. (22) reported a subintimal
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CS dissection rate of 4.3 and 1.1% leakage of radiocontrast into the pericardial space. In the MIRACLE study (2,21), the authors reported two deaths (0.4%), CS dissection (4%), and cardiac-vein or CS perforation requiring pericardiocentesis (2%). In the present study, there was a CS perforation in the conventional group and a leakage of contrast into the pericardium in the CS-assist group, which was less than the reported complication rate, suggesting that the CSassist catheter is safe and does not increase the risk of more complications during the CS cannulation. The decapolar CS catheter has earlier been used to facilitate CS cannulation in difficult cases (7). Differing from the existing CS catheter, the CSassist catheter is purely dedicated to facilitate CS cannulation in the CRT procedures. It is 40% shorter (65 cm) than the ordinary CS catheters (110 cm) that makes it easier and more convenient to use. The bipolar electrode configuration is another advantage for its simplicity in getting intracardiac electrogram guidance as mentioned above. In addition, the bipolar catheter is much less expensive than the decapolar catheter. Limitations of the study The current study is not a randomized study. However, consecutive patients for the CRT implantation were recruited both to the CS-assist group and to the conventional group, which could minimize patient selection bias. In addition, the study group patients were recruited prospectively and compared to those before the use of the CS-assist catheter technique and all operations were performed by the same operator. Thus, the CS-assist technique was relatively new to the operator, while the conventional CS cannulation technique with a Terumo, a direct lead, or a guide wire without real-time electrogram guidance was the operator more skillful at. Therefore one has reasons to believe that the results may not relate to the skill and experience of the operator rather to the different CS cannulation techniques. Furthermore, the present study may have been limited by the relatively small study population from a single center, especially regarding identification of any CS cannulation failure in the CS-assist group. Another limitation of this study was that we did not measure the time for the CS cannulation itself, since the procedure and fluoroscopy times may have interfered with other factors, such as the time to obtain vascular access, to implant the right atrial and ventricular lead, and to introduce the LV lead to the tributary CS vein. However, all operations in this study were performed by the same operator with the same supporting staff, and in principle the time used for the above-mentioned
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procedures was the same for each group of patients. Thus, the statistically significant differences between the two groups in procedure and fluoroscopy times were mainly due to the difference in the CS cannulation time between the two groups, indicating the beneficial effect of the CS-assist catheter technique. Conclusions Using the steerable catheter with real-time electrogram guidance during the CRT implantation makes location of and access to the CS more rapid and successful, thus improving the success rate of the CRT implantation and saving both implantation and fluoroscopy times. Acknowledgements We thank Professor David Erlinge, Department of Cardiology, Skane University Hospital, Lund University, for his support and critical review of the manuscript and Kristoffer Nibble, Stefan Larsson for their technical assistance. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper. References 1. Haennel RG. Exercise rehabilitation for chronic heart failure patients with cardiac device implants. Cardiopulm Phys Ther J. 2012;23:23–8. 2. Abraham WT, Fisher WG, Smith AL, Delurgio DB, Leon AR, Loh E, et al. Cardiac resynchronization in chronic heart failure. N Engl J Med. 2002;346:1845–53. 3. Bisch L, Da Costa A, Dauphinot V, Romeyer-Bouchard C, Khris L, M’Baye A, Isaaz K. Predictive factors of difficult implantation procedure in cardiac resynchronization therapy. Europace. 2010;12:1141–8. 4. Cazeau S, Leclercq C, Lavergne T, Walker S, Varma C, Linde C, et al. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N Engl J Med. 2001;344:873–80. 5. Daoud EG, Kalbfleisch SJ, Hummel JD, Weiss R, Augustini RS, Duff SB, et al. Implantation techniques and chronic lead parameters of biventricular pacing dualchamber defibrillators. J Cardiovasc Electrophysiol. 2002; 13:964–70. 6. Mak GS, Hill AJ, Moisiuc F, Krishnan SC. Variations in Thebesian valve anatomy and coronary sinus ostium: implications for invasive electrophysiology procedures. Europace. 2009;11:1188–92.
7. Kappos KG, Papadopoulou E, Manolis AS. Techniques of implantation of a biventricular pacing system. Hospital Chronicles. 2008;3:178–84. 8. Randhawa A, Saini A, Aggarwal A, Rohit MK, Sahni D. Variance in coronary venous anatomy: a critical determinant in optimal candidate selection for cardiac resynchronization therapy. Pacing Clin Electrophysiol. 2013;36:94–102. 9. Ortale JR, Gabriel EA, Iost C, Marquez CQ. The anatomy of the coronary sinus and its tributaries. Surg Radiol Anat. 2001;23:15–21. 10. Chiang CE, Chen SA, Yang CR, Cheng CC, Wu TR, Tsai DS, et al. Major coronary sinus abnormalities: identification of occurrence and significance in radiofrequency ablation of supraventricular tachycardia. Am Heart J. 1994; 127:1279–89. 11. Noheria A, Desimone CV, Lachman N, Edwards WD, Gami AS, Maleszewski JJ, et al. Anatomy of the Coronary Sinus and Epicardial Coronary Venous System in 620 Hearts: An Electrophysiology Perspective. J Cardiovasc Electrophysiol. 2013;24:1–6. 12. Silver MA, Rowley NE. The functional anatomy of the human coronary sinus. Am Heart J. 1988;115:1080–4. 13. Karaca M, Bilge O, Dinckal MH, Ucerler H. The anatomic barriers in the coronary sinus: implications for clinical procedures. J Interv Card Electrophysiol. 2005;14:89–94. 14. Hill AJ, Ahlberg SE, Wilkoff BL, Iaizzo PA. Dynamic obstruction to coronary sinus access: the Thebesian valve. Heart Rhythm. 2006;3:1240–1. 15. Duda B, Grzybiak M. Variability of valve configuration in the lumen of the coronary sinus in the adult human hearts. Folia Morphol (Warsz). 2000;59:207–9. 16. Hsu JC, Badhwar N, Lee BK, Vedantham V, Tseng ZH, Marcus GM. Predictors of fluoroscopy time and procedural failure during biventricular device implantation. Am J Cardiol. 2012;110:240–5. 17. Romeyer-Bouchard C, Da Costa A, Dauphinot V, Messier M, Bisch L, Samuel B, et al. Prevalence and risk factors related to infections of cardiac resynchronization therapy devices. Eur Heart J. 2010;31:203–10. 18. Ahsan SY, Saberwal B, Lambiase PD, Chaubey S, Segal OR, Gopalamurugan AB, et al. An 8-year single-centre experience of cardiac resynchronisation therapy: procedural success, early and late complications, and left ventricular lead performance. Europace. 2013;15:711–7. 19. Butter C, Schau T, Meyhoefer J, Neumann K, Minden HH, Engelhardt J. Radiation exposure of patient and physician during implantation and upgrade of cardiac resynchronization devices. Pacing Clin Electrophysiol. 2010;33: 1003–12. 20. Brambilla M, Occhetta E, Ronconi M, Plebani L, Carriero A, Marino P. Reducing operator radiation exposure during cardiac resynchronization therapy. Europace. 2010; 12:1769–73. 21. van Rees JB, de Bie MK, Thijssen J, Borleffs CJ, Schalij MJ, van Erven L. Implantation-related complications of implantable cardioverter-defibrillators and cardiac resynchronization therapy devices: a systematic review of randomized clinical trials. J Am Coll Cardiol. 2011;58:995–1000. 22. Kautzner J, Riedlbauchova L, Cihak R, Bytesnik J, Vancura V. Technical aspects of implantation of LV lead for cardiac resynchronization therapy in chronic heart failure. Pacing Clin Electrophysiol. 2004;27:783–90.
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ORIGINAL ARTICLE
Coronary sinus cannulation with a steerable catheter during biventricular device implantation*
LINGWEI WANG, SHIWEN YUAN, RASMUS BORGQUIST, CARL-JOHAN HÖIJER & JOHAN BRANDT Department of Arrhythmias, Skane University Hospital, Lund University, Lund, Sweden
Abstract Objectives. To determine whether a steerable catheter with electrogram guidance (CS-assist group) could facilitate access to the coronary sinus (CS) during cardiac resynchronization therapy (CRT) implantation. Design. Consecutive patients who underwent CRT implantation were recruited prospectively into the CS-assist group (n ⫽ 81) and compared with those using conventional techniques without an electrogram guidance (conventional group, n ⫽ 101). Results. The CS cannulation success rate was clearly greater in the CS-assist group (100%) than that in the conventional group (95%, p ⬍ 0.05), with significantly shorter mean procedure time (52.6 ⫾ 20.6 min vs. 73.2 ⫾ 40.9 min, p ⬍ 0.01) and fluoroscopy time (3.6 ⫾ 3.2 min vs. 14.2 ⫾ 20.4 min, p ⬍ 0.01). In the five CS cannulation failure cases, mean procedure time (144.0 ⫾ 37.0 min) and fluoroscopy time (57.8 ⫾ 24.8 min) were significantly longer than those in the other patients (61.2 ⫾ 32.3 and 8.2 ⫾ 13.6 min, respectively, n ⫽ 177, both p ⬍ 0.01). Conclusions. Using the steerable catheter with real-time electrogram guidance, location of and access to the CS is more rapid and successful, which may improve the success of the CRT implantation and may give significant time savings. Key words: cardiac resynchronization therapy, coronary sinus cannulation, electrogram guidance, heart failure
Introduction Heart failure is a major healthcare problem and is associated with both morbidity and mortality (1). Cardiac resynchronization therapy (CRT) is one of the most important therapeutic advances in recent years for drug-refractory, chronic congestive heart failure with electromechanical dyssynchrony; it can improve quality of life and reduce mortality (2). During CRT operations, gaining access to the coronary sinus (CS) can be a challenging and a timeconsuming process. Valves, ridges, and unexpected anatomical changes due to natural or surgical causes can increase the time required to access the CS, and there is a 5–15% failure rate according to clinical reports (3–6). CS cannulation using electrode catheter and electrogram guidance is widely used in electrophysiological laboratories, but not yet in CRT implantation. To our knowledge, there has not been any publication
before concerning the use of a steerable catheter and electrogram guidance during the CRT implantation, though electrophysiology (EP) catheters have been used in clinical practice (7). Recently, a steerable catheter with electrogram guidance (CS-assist catheter) was developed to help gain access to the CS during CRT implantation. In the present study, we aimed to systematically determine the feasibility and efficacy of using the CS-assist catheter in patients undergoing CRT implantation. Material and methods Study population From September 2011 to September 2012, consecutive patients referred to our center for CRT implantation were prospectively recruited into the study (CS-assist group, n ⫽ 81). The results were compared to those of consecutive patients for the
*The paper has been presented at EHRA EUROPACE 2013 in Athens, Greece from 23–26 June 2013 and the 39th International Congress on Electrocardiology in Beijing, China from 8–11 August 2012. Correspondence: Dr Lingwei Wang, Department of Arrhythmias, Skane University Hospital, Lund University, SE-211 85 Lund, Sweden. Tel: ⫹ 4646171680. Fax: ⫹ 4646 323574. E-mail: [email protected] (Received 21 October 2013 ; revised 11 December 2013 ; accepted 11 December 2013) ISSN 1401-7431 print/ISSN 1651-2006 online © 2014 Informa Healthcare DOI: 10.3109/14017431.2013.875623
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CRT implantations between January 2010 and September 2011 using conventional techniques (Conventional group, n ⫽ 101) with Terumo, direct lead, or guide wire without electrophysiological catheter and/or real-time electrogram guidance. All the operations were performed by a single operator using the access of the left cephalic and subclavian vein. CRT implantations from the right side and/or those performed by other operators were excluded. The study complied with the Declaration of Helsinki and was approved by the investigational review board at Lund University Hospital, Sweden. The informed consent of the patients had been obtained.
The CS-assist catheter The CS-assist catheter (Bard Electrophysiology Inc.) is designed merely for CRT implantation. It is 6 French with 65-cm usable length and two electrodes at 5-mm spacing on the deflectable tip. Different from the conventional EP diagnostic CS catheter that is 110-cm long with 10 electrodes, the CS-assist catheter gives easier ergonomic manipulation, and its bipolar electrode configuration provides simple mapping capability.
Intracardiac mapping and CS cannulation During the cannulation with the CS-assist catheter, bipolar electrograms were recorded and displayed in real time using an EP Recording System (LabSystem™ PRO, Bard Electrophysiology Inc.). This helped us to identify the location of the catheter (Figure 1). Using the CS-assist catheter with real-time electrogram guidance, we could try the posterior, superior, anterior, or inferior approaches to access the CS. We mostly succeeded in gaining access to the CS from an anterior (ventricular) and inferior approaches, due to the anatomy of the CS and the presence of the Thebesian valve. Using the ventricular approach, we first placed the tip inferiorly in the right ventricle and then bent the catheter tip while rotating it counter-clockwise, that is, we let the tip point inferoposteriorly toward the posterior septum. When the bipolar electrogram changed from a dominant V-deflection to a dominant Adeflection, the catheter was advanced toward the CS ostium posteriorly. If the catheter entered the CS, one could see a dominant A⫺ or balanced A/V-deflections all the time from the recording. These electrogram features were present even when the patient was in atrial fibrillation. If the dominant V-deflections appeared again, it indicated that the catheter was back into the ventricle and that the
Figure 1. Bipolar electrogram (EG) recorded via tip electrodes of the CS-assist catheter together with ECG lead III (III). A: Catheter from right ventricle (RV) to right atrium (RA). Only ventricular deflection and no atrial deflection suggested its right ventricular location. After withdrawal and counter-clockwise rotation, a dominant A-deflection was suddenly seen, suggesting that it had reached the AV junction near the CS ostium. B: At the CS ostium, the catheter was advanced posterolaterally while a dominant A-deflection was still present, indicating that the tip was at or already in the CS ostium; otherwise, a large V-deflection would have appeared. C: The catheter was further advanced laterally without resistance, while a dominant or fairly large A- and V-deflections were present all the time, suggesting that the catheter was deeply in the CS.
above procedures should be repeated. When it was difficult to access the CS ostium, very often it was because of hindrance by the Thebesian valve. Further bending of the catheter at the CS ostium followed by immediate release and advancement of the catheter could help in getting through the Thebesian valve.
Coronary sinus cannulation with a steerable catheter Main parameters and statistical methods In comparing the two groups, CS cannulation success rate, procedure time, and fluoroscopy time were used as the main parameters. In addition, any complications related to the CS cannulation were recorded. Data were reported as mean ⫾ SD (median) if not especially indicated. For statistical analysis of comparisons, non-parametric Wilcoxon–Mann–Whitney test was used for the procedure times and fluoroscopy times and Student’s t test or Chi-square test was used for success rate and clinical data. Differences were considered significant at P values less than 0.05.
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than that in the conventional group, 73.2 ⫾ 40.9 (65) min, (p ⬍ 0.01). Procedure time in the five CS cannulation failure cases (144.0 ⫾ 37.0 (155) min, n ⫽ 5) was significantly longer than that in the other patients (61.2 ⫾ 32.3 (59) min, n ⫽ 177; p ⬍ 0.01). Fluoroscopy time in the CS-assist group (3.6 ⫾ 3.2 (2.6) min) was significantly shorter than that in the conventional group (14.2 ⫾ 20.4 (7.1) min) (p ⬍ 0.01). Fluoroscopy time in the five CS cannulation failure cases (57.8 ⫾ 24.8 (59.0) min) was significantly longer than that in the rest of the patients (8.2 ⫾ 13.6 (3.9) min, n ⫽ 177; p ⬍ 0.01). Special cases
Results Cannulation success rate We included 182 consecutive patients aged 69.1 ⫾ 12.0 years who received CRT implantations by the same operator. The clinical data are presented in Table I. There were five failures in CS cannulation (5%) in the conventional group (n ⫽ 101), whereas there were no failures in the CS-assist group (n ⫽ 81). Thus, the success rate of CS cannulation was much higher in the CS-assist group (100%) than in the conventional group (95%, p ⬍ 0.05). Of the five CS-cannulation failures, the left ventricular (LV)-lead was placed in the right ventricular outflow tract at the same procedure in three, and the LV-lead placement succeeded later at a second procedure in one. The fifth patient unfortunately died 1.5 months after the first procedure before the scheduled re-operation.
Total procedure time and fluoroscopy time Total procedure time (skin-to-skin) in the CS-assist group, 52.6 ⫾ 20.6 (50) min, was significantly shorter
There were two patients in the CS-assist group in whom CS cannulation had failed in a previous procedure. Case 1 had had CS cannulation failure before (procedure time: 92 min and fluoroscopy time: 40.4 min). In the present procedure (procedure time: 75 min and fluoroscopy time: 6.7 min), we experienced resistance around the CS ostium and succeeded in CS cannulation by further bending the CS-assist catheter at the CS ostium followed by immediate release and advancement of the catheter. The CS sheath could not follow the catheter into the CS, due to resistance around the CS. CS venography showed that the CS sheath was located exactly at the CS ostium and a Thebesian valve covered almost the entire CS ostium (Figure 2), which could have been the reason for the difficulties in performing this procedure and for the failure of the previous one. In Case 2, CS cannulation had failed in a previous procedure with a fluoroscopy time of 60 min. At the present procedure with the CS-assist catheter (procedure time: 35 min and fluoroscopy time: 0.9 min), there was some resistance around the CS ostium when the CS sheath entered the CS along the CS-assist catheter, but it did not affect the process of CS cannulation. There was also a Thebesian valve
Table I. Clinical characteristics. Patient characteristic Age (years) Gender (% male) Ejection fraction (%) NYHA class Coronary artery disease (%) Previous CABG (%) CRT during paroxysmal AF (%) CRT in permanent AF (%) Primary CRT implantation (%) Primary LV lead implant (%)
CS-assist group (n ⫽ 81) 69.2 ⫾ 10.7 74.1 24.1 ⫾ 4.9 2.8 ⫾ 0.5 48.1 23.5 12.3 21.0 79.0 95.1
Conventional group (n ⫽ 101) 69.0 ⫾ 12.2 82.2 25.4 ⫾ 5.9 2.8 ⫾ 0.5 39.6 22.8 13.9 21.8 70.3 95.1
CABG, coronary artery bypass grafting; AF, atrial fibrillation; LV, left ventricular None of differences in the above characteristics were statistically significant between the two groups.
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L. Wang et al. Discussion The CS is the gateway for LV lead placement in CRT (8). CS cannulation is a critical prerequisite for this therapy. The recently developed CS-assist catheter with the real-time electrogram guidance is dedicated for identifying the CS ostium and facilitating the access to the CS during the CRT implantation. To our knowledge, no systematic clinical evaluation of this catheter technique has been published. The present study has shown that using the CS-assist catheter with deflectable tip and intracardiac electrogram guidance, localization, and access to the CS was more rapid and successful, which improved the success of CRT implantation—with significant savings in implantation and fluoroscopy times.
Anatomical aspects Figure 2. CS venography from a 78-year-old man in the CS-assist group (special case no. 1) with chronic atrial fibrillation and CS cannulation failure in a previous procedure. During the venography, there was no leakage of contrast in all superior or posterior approach, while slight leakage was seen anterior and inferior approaches, which was markedly different from the venography findings in most of our patients. This indicates the presence of the Thebesian valve covering the posterior and superior aspects of the CS ostium and explains the difficulties in the CS cannulation— both in the previous and in the current procedures.
covering the CS ostium. The procedure times and fluoroscopy times in these two difficult cases were nevertheless shorter in the present procedure with the CS-assist catheter than in the previous one without the CS-assist catheter. Complications One patient in the conventional group had CS perforation during the LV lead delivery because of an S-shaped narrow curve in the tributary CS vein. Before the perforation, there was obvious resistance. The patient recovered without sequelae after percutaneous pericardial drainage. CRT implantation succeeded two months later. There was also a patient in the CS-assist group who had leakage of contrast into the pericardium during cannulation. This was one of our earliest cases using the CSassist catheter. A stenosis and a valve in the main stem of the CS were detected, and we met resistance at the stenosis when passing the CS sheath at selective CS venography. Slight leakage of contrast into the pericardium was found. Echocardiography did not show any clear pericardial effusion and the patient recovered without further treatment.
The CS ostium is 5–15 mm in diameter and is located on the inferior-posterior interatrial septum, anterior to the Eustachian ridge and valve, and posterior to the tricuspid annulus (9). Like the rest of the cardiac venous system, the CS contains various valves, including the Thebesian valve and Vieussens valve. These valves are sometimes important obstacles, obstructing the CS sheath—and thereby the LV lead—from advancing into the cardiac veins (10). The most common valve is the Thebesian valve at the ostium of the CS (8,11), a caudal remnant of the embryonic sinoatrial valves. This valve can present with variable shape (12). It can be semilunar, fenestrated, or band-shaped (13), and occasionally it causes dynamic obstruction (14). Postmortem studies have found the presence of Thebesian valves in more than 70% of hearts (6). The valve may cover the CS ostium from 0% to 100% (13), and it may be a potentially complicating structure and an obstacle during cannulation of the CS (14). The orientation of the Thebesian valve favors cannulation of the CS from an anterior (ventricular) and inferior approach (11). This could easily be done using the CS-assist catheter, as demonstrated by our special case no. 1. Moreover, Duda and Grzybiak reported a 10% incidence of a Vieussens valve in the lumen of the CS itself (15), with a complete single valve totally dividing the lumen of the CS into two in 1.3% of cases. This can be another problem during the CS cannulation. Use of the CS-assist catheter could help in passing the Vieussens valve, by bending and/or rotation of this catheter. The CS dissection in one of our earliest cases in the CS-assist group probably occurred when trying to pass a Vieussens valve in the main stem of the CS without having enough experience of the equipment. After that, we had two other
Coronary sinus cannulation with a steerable catheter similar cases with a valve in the main stem, and we succeeded with the CS cannulation with the help of the CS-assist catheter in both. One of the pitfalls of CS cannulation is repeatedly entering the right ventricle, without recognizing it from a single fluoroscopic view, before ventricular extra beats were induced. Using the CS-assist catheter with real-time electrogram guidance, one knows all the time whether the catheter tip is in the ventricle or in the atrium—and especially if it is in the posterior A/V junction where the CS ostium is located. With the help of electrogram guidance, the catheter tip never moves away from this area and the chances of entering the CS are considerably greater. In addition to electrogram guidance, the steerable tip of the CS-assist catheter is an appreciable help in getting through the Thebesian and Vieussens valves as described above. Clinical considerations CS cannulation failure is one of the most important factors affecting the success rate of the CRT. The reported failure rate in the CS cannulation ranges from 5 to 15% (3–6), with the most recent data indicating 2.9% failure (16). This is consistent with the general CS cannulation failure in our patients (5 out of 182, 2.7%), whereas there was no failure in our CS-assist group. This shows clearly that the new technique can improve the success rate of CRT by facilitation of CS cannulation. The total average procedure time of CRT has been reported to be between 67 and 167 min and average fluoroscopy times from 18 to 36 min (16– 18), depending on different routines and experience. Our results showed short procedure times and fluoroscopy times in both groups. Nevertheless, the procedure and fluoroscopy times in the CS-assist group were significantly shorter than in the conventional group and in the published clinical data (16–18), suggesting that the CS-assist catheter has a beneficial effect independent of other factors. Among several others, reduced procedure time has been showed to be a factor that is predictive of fewer device-related infections (21). In addition, there has been growing concern regarding the radiation-induced cell injury, malignant diseases, and heritable effects (19,20). In these respects, the reduced fluoroscopy time with CS-assist catheters could reduce the radiation injury to both patients and physicians during the CRT implantation. Coronary vein dissection and perforation are one of the most common complications associated with the insertion of the LV lead during the CRT implantation. The complication rate ranges from 1.9 to 4.6% (21). Kautzner et al. (22) reported a subintimal
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CS dissection rate of 4.3 and 1.1% leakage of radiocontrast into the pericardial space. In the MIRACLE study (2,21), the authors reported two deaths (0.4%), CS dissection (4%), and cardiac-vein or CS perforation requiring pericardiocentesis (2%). In the present study, there was a CS perforation in the conventional group and a leakage of contrast into the pericardium in the CS-assist group, which was less than the reported complication rate, suggesting that the CSassist catheter is safe and does not increase the risk of more complications during the CS cannulation. The decapolar CS catheter has earlier been used to facilitate CS cannulation in difficult cases (7). Differing from the existing CS catheter, the CSassist catheter is purely dedicated to facilitate CS cannulation in the CRT procedures. It is 40% shorter (65 cm) than the ordinary CS catheters (110 cm) that makes it easier and more convenient to use. The bipolar electrode configuration is another advantage for its simplicity in getting intracardiac electrogram guidance as mentioned above. In addition, the bipolar catheter is much less expensive than the decapolar catheter. Limitations of the study The current study is not a randomized study. However, consecutive patients for the CRT implantation were recruited both to the CS-assist group and to the conventional group, which could minimize patient selection bias. In addition, the study group patients were recruited prospectively and compared to those before the use of the CS-assist catheter technique and all operations were performed by the same operator. Thus, the CS-assist technique was relatively new to the operator, while the conventional CS cannulation technique with a Terumo, a direct lead, or a guide wire without real-time electrogram guidance was the operator more skillful at. Therefore one has reasons to believe that the results may not relate to the skill and experience of the operator rather to the different CS cannulation techniques. Furthermore, the present study may have been limited by the relatively small study population from a single center, especially regarding identification of any CS cannulation failure in the CS-assist group. Another limitation of this study was that we did not measure the time for the CS cannulation itself, since the procedure and fluoroscopy times may have interfered with other factors, such as the time to obtain vascular access, to implant the right atrial and ventricular lead, and to introduce the LV lead to the tributary CS vein. However, all operations in this study were performed by the same operator with the same supporting staff, and in principle the time used for the above-mentioned
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procedures was the same for each group of patients. Thus, the statistically significant differences between the two groups in procedure and fluoroscopy times were mainly due to the difference in the CS cannulation time between the two groups, indicating the beneficial effect of the CS-assist catheter technique. Conclusions Using the steerable catheter with real-time electrogram guidance during the CRT implantation makes location of and access to the CS more rapid and successful, thus improving the success rate of the CRT implantation and saving both implantation and fluoroscopy times. Acknowledgements We thank Professor David Erlinge, Department of Cardiology, Skane University Hospital, Lund University, for his support and critical review of the manuscript and Kristoffer Nibble, Stefan Larsson for their technical assistance. Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper. References 1. Haennel RG. Exercise rehabilitation for chronic heart failure patients with cardiac device implants. Cardiopulm Phys Ther J. 2012;23:23–8. 2. Abraham WT, Fisher WG, Smith AL, Delurgio DB, Leon AR, Loh E, et al. Cardiac resynchronization in chronic heart failure. N Engl J Med. 2002;346:1845–53. 3. Bisch L, Da Costa A, Dauphinot V, Romeyer-Bouchard C, Khris L, M’Baye A, Isaaz K. Predictive factors of difficult implantation procedure in cardiac resynchronization therapy. Europace. 2010;12:1141–8. 4. Cazeau S, Leclercq C, Lavergne T, Walker S, Varma C, Linde C, et al. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N Engl J Med. 2001;344:873–80. 5. Daoud EG, Kalbfleisch SJ, Hummel JD, Weiss R, Augustini RS, Duff SB, et al. Implantation techniques and chronic lead parameters of biventricular pacing dualchamber defibrillators. J Cardiovasc Electrophysiol. 2002; 13:964–70. 6. Mak GS, Hill AJ, Moisiuc F, Krishnan SC. Variations in Thebesian valve anatomy and coronary sinus ostium: implications for invasive electrophysiology procedures. Europace. 2009;11:1188–92.
7. Kappos KG, Papadopoulou E, Manolis AS. Techniques of implantation of a biventricular pacing system. Hospital Chronicles. 2008;3:178–84. 8. Randhawa A, Saini A, Aggarwal A, Rohit MK, Sahni D. Variance in coronary venous anatomy: a critical determinant in optimal candidate selection for cardiac resynchronization therapy. Pacing Clin Electrophysiol. 2013;36:94–102. 9. Ortale JR, Gabriel EA, Iost C, Marquez CQ. The anatomy of the coronary sinus and its tributaries. Surg Radiol Anat. 2001;23:15–21. 10. Chiang CE, Chen SA, Yang CR, Cheng CC, Wu TR, Tsai DS, et al. Major coronary sinus abnormalities: identification of occurrence and significance in radiofrequency ablation of supraventricular tachycardia. Am Heart J. 1994; 127:1279–89. 11. Noheria A, Desimone CV, Lachman N, Edwards WD, Gami AS, Maleszewski JJ, et al. Anatomy of the Coronary Sinus and Epicardial Coronary Venous System in 620 Hearts: An Electrophysiology Perspective. J Cardiovasc Electrophysiol. 2013;24:1–6. 12. Silver MA, Rowley NE. The functional anatomy of the human coronary sinus. Am Heart J. 1988;115:1080–4. 13. Karaca M, Bilge O, Dinckal MH, Ucerler H. The anatomic barriers in the coronary sinus: implications for clinical procedures. J Interv Card Electrophysiol. 2005;14:89–94. 14. Hill AJ, Ahlberg SE, Wilkoff BL, Iaizzo PA. Dynamic obstruction to coronary sinus access: the Thebesian valve. Heart Rhythm. 2006;3:1240–1. 15. Duda B, Grzybiak M. Variability of valve configuration in the lumen of the coronary sinus in the adult human hearts. Folia Morphol (Warsz). 2000;59:207–9. 16. Hsu JC, Badhwar N, Lee BK, Vedantham V, Tseng ZH, Marcus GM. Predictors of fluoroscopy time and procedural failure during biventricular device implantation. Am J Cardiol. 2012;110:240–5. 17. Romeyer-Bouchard C, Da Costa A, Dauphinot V, Messier M, Bisch L, Samuel B, et al. Prevalence and risk factors related to infections of cardiac resynchronization therapy devices. Eur Heart J. 2010;31:203–10. 18. Ahsan SY, Saberwal B, Lambiase PD, Chaubey S, Segal OR, Gopalamurugan AB, et al. An 8-year single-centre experience of cardiac resynchronisation therapy: procedural success, early and late complications, and left ventricular lead performance. Europace. 2013;15:711–7. 19. Butter C, Schau T, Meyhoefer J, Neumann K, Minden HH, Engelhardt J. Radiation exposure of patient and physician during implantation and upgrade of cardiac resynchronization devices. Pacing Clin Electrophysiol. 2010;33: 1003–12. 20. Brambilla M, Occhetta E, Ronconi M, Plebani L, Carriero A, Marino P. Reducing operator radiation exposure during cardiac resynchronization therapy. Europace. 2010; 12:1769–73. 21. van Rees JB, de Bie MK, Thijssen J, Borleffs CJ, Schalij MJ, van Erven L. Implantation-related complications of implantable cardioverter-defibrillators and cardiac resynchronization therapy devices: a systematic review of randomized clinical trials. J Am Coll Cardiol. 2011;58:995–1000. 22. Kautzner J, Riedlbauchova L, Cihak R, Bytesnik J, Vancura V. Technical aspects of implantation of LV lead for cardiac resynchronization therapy in chronic heart failure. Pacing Clin Electrophysiol. 2004;27:783–90.
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