438

Letters to the Editor

Cerebral microembolism during transradial coronary angiography: Comparison between single and double catheter strategy Andrea Pacchioni a,⁎, Antonio Mugnolo a, Carlo Penzo a, Dimitrios Nikas a, Salvatore Saccà a, Pierfrancesco Agostoni b, Zsolt Garami c, Francesco Versaci d, Bernhard Reimers a a

Divisione di Cardiologia, Ospedale Civile, Mirano, Italy Department of Cardiology, University Medical Center, Utrecht, Netherlands Department of Cardiovascular Surgery, Methodist DeBakey Heart and Vascular Center, The Methodist Hospital, Houston, USA d Unità Operativa di Cardiologia, Ospedale di Campobasso ed Isernia, Italy b c

a r t i c l e

i n f o

Article history: Received 25 July 2013 Revised 18 November 2013 Accepted 23 November 2013 Available online 4 December 2013 Keywords: Transradial access Cerebral microembolism Transcranial Doppler

Silent cerebral embolization, related to air embolism, blood clots, platelet aggregates or dislodged atheromatous debris, is common during endovascular procedures and can be detected appropriately by transcranial doppler (TCD) scan [1]. Right transradial approach (RTA) has shown higher incidence of microembolism compared to transfemoral and left transradial, especially in the right hemisphere, related to increased mechanical manipulation and higher catheter exchange rate when Judkins catheters were employed [2,3]. The number of catheters employed, more than the vascular access, has been found to be related to both silent and symptomatic cerebral emboli [2,4] with increasing risk when higher number of catheters was employed. In fact, procedures needing N 2 catheters generated 50% more microemboli in comparison to procedures needing 2 catheters [2]. Judkins pre-shaped curves are still the first choice among most transradialist operators [5] and must be rotated to afford the S-shaped geometry of the right subclavian-innominate-aorta axis [2,3] with increased risk of failure. A single, properly designed catheter fitting both coronaries is available [6] and it has high procedural success rate, less radial artery spasm, radiation exposure and procedural time [6,7]. We sought to evaluate if it could also reduce the incidence of cerebral microembolism. In our experience (70 unselected patients who underwent TCD-monitored coronary angiographies through RTA) we found a total amount of 4970 microembolic signals (MES, mean 71, standard deviation ± 28) and we hypothesized that SC strategy, compared to DC strategy, could reduce MES of 50%. Therefore, a minimum of 9 patients for each group had to be enrolled to detect this difference (80% power at p b 0.05). Accordingly so, 19 consecutive patients with suspected coronary artery disease were randomized to coronary angiography through RTA with single (SC) or double catheter (DC) strategy, with contemporaneous TCD monitoring of both middle cerebral arteries (MCAs). Exclusion criteria were atrial fibrillation, previous by-pass coronary surgery, hemodynamic instability, need for left ventricle catheterization, insufficient acoustic temporal bone window and severe carotid stenosis. Primary endpoint was the overall amount of microembolic signals (MEStot). The study was approved by our local Ethical Committee and all patients gave written consent. Coronary angio-

⁎ Corresponding author at: Cardiology Department, Mirano General Hospital, via Mariutto 13, Mirano, Italy. Tel.: +39 0415794241. E-mail address: [email protected] (A. Pacchioni).

graphy was performed according to standard procedure. All patients were pretreated with acetylsalicyclic acid and clopidogrel, and received 2500 U of heparin. Procedural success was defined as completion of procedure with single catheter (6 French Optitorque Tiger II, Terumo, Terumo Europe, Leuven, Belgium) in the SC group and with 2 catheters (6 French Judkins Left and Right, Cordis Corporation, Miami, USA) in the DC group. MCAs were continuously monitored with power M-Mode Doppler system (ST3, Spencer Technologies, Seattle, WA, USA) and MES were automatically identified and counted while the time of their occurrence was recorded. An examiner reviewed the blinded, recorded exams offline, assigning MES to different stages of coronary angiography: [1] catheter manipulation (MESman), further distinguished in: - manipulation in aortic arch and coronary ostia engagement (MEScor), and catheter exchange, including advancement and over-the wire removal of catheters and insertion of the wire to overcome tortuosity (MESexch); [2] injection of contrast medium and catheter flushing (MESinj). MEStot was the sum of MES occurring at each stage (MEStot = MEScor + MESexch + MESinj). Analysis of primary endpoint was performed according to intention-to-treat. Parametric variables were compared with two tailed Student's T-test, non parametric with two tailed Mann–Whitney U test and categorical with chi2 or Fisher exact test. Relation among MES and other variables was assessed by bivariate correlation and linear regression. No significant differences in baseline characteristics of patients are present between the two groups (Table 1). Procedural success was achieved in 8 (88%) cases in SC and in 9 (90%) of DC group (p = 1); the only significant difference was the number of catheters employed, as expected (1.11 ± 0.33 vs 2.1 ± 0.3, p b 0.0001). In both cases of procedural failure, an adjunctive catheter was needed to perform selective catheterization of right coronary artery (Judkins Right 4 in patient of SC group and Amplatz Left 1 in patient of DC group). No clinical events were reported; however, MES were detected in all patients with a significant lower rate in the SC group (MEStot: median 30 [IQR 16–45], vs 57 [54–69], p b 0.0001), which also generated less MESman (23 [13–33], vs 47 [37–60], p = 0.001) and especially MESexch (19 [11–25], vs 41 [27–49], p = 0.003). A similar rate of MEScor (2 [1– 6], vs 8 [1–11], p = 0.156) and MESinj was detected (5 [1–13], vs 9 [5– 17], p = 0.243) (Fig. 1). In addition, an individual analysis of each MCA indicated that SC strategy reduced MEStot, MESman and MESexch in both right and left MCA (Table 1). Strong negative correlation is present between SC strategy and MEStot (rho = −0.59, p b 0.0001) with 50% reduction of MEStot incidence (B = − 16.58, SE = 3.6, beta = − 0.7, t = − 4.5, 95% IC = −24/−9, costant = 37, aR2 = 0.35, p = 0.001). Silent cerebral embolization during transradial coronary angiography is significantly reduced using a single catheter for catheterization of both left and right coronary arteries, as a consequence of dramatic reduction of catheter exchanges. Most of the advantage, indeed, is related to the reduction of microemboli generated during catheter exchange maneuvers. This could be related to air bubbles created by microcavitation during wire insertion and catheter exchanges. Further reduction of microembolism could be achieved performing procedures with SC strategy through left transradial approach.

Letters to the Editor

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Table 1 Characteristics of the patients and results. Characteristics value

Age - yrsa Male Hypertension Diabetes Current smoking Dyslipidemia Chronic renal failure c Previous myocardial infarction Previous stroke/TIA Previous PCI Acute coronary syndrome Absence of CAD CAD 1 vessel CAD 2 vessel CAD 3 vessel Subsequent PCI Left ventricle ejection fractiona Fluoroscopic time (s)a Contrast medium amount (ml)a Number of cathetersa b MEStot MESinj b MESman b MESexch b MEScor b MEStot in right MCA b MEStot in left MCA b MESinj in RMCA b MESinj in LMCA b MESman in RMCA b MESman in LMCA b MESexch in RMCA b MESexch in LMCA b MEScor in RMCA b MEScor in LMCA b

Single catheter approach

Double catheter approach

(n = 9)

(n = 10)

69.3 + 7 6 (66.7%) 9 (100%) 3 (33%) 1 (11.1%) 6 (66.7%) 2 (22.2%) 2 (22.2%) 1 (11.1%) 4 (44.4%) 4 (44.4%) 2 (22.2%) 1 (11.1%) 2 (22.2%) 4 (44.4%) 8 (88.9%) 55 + 7 190 ± 50 47 ± 10 1.1 ± 0.3 30 (16–45) 5 (1–13) 23 (13–33) 19 (11–25) 2 (1–6) 22 (8–30) 12 (5–15) 3 (0–9) 2 (1–4) 15 (7–24) 7 (3–11) 12 (6–19) 7 (3–9) 1 (0–5) 1 (0–2)

63.3 + 13 7 (70%) 7 (70%) 1 (10%) 5 (50%) 8 (80%) 0 (0%) 4 (40%) 1 (10%) 3 (30%) 7 (70%) 1 (10%) 3 (30%) 5 (50%) 1 (10%) 7 (70%) 52.5 + 11 171 ± 37 41 ± 7 2.1 ± 0.3 57 (54–69) 9 (5–17) 47 (37–60) 41 (27–49) 8 (1–11) 32 (29–45) 26 (16–31) 3 (0–7) 4 (2–6) 28 (23–33) 19 (12–25) 26 (14–33) 15 (9–22) 3 (0–7) 2 (0–4)

P value

0.23 1 0.21 0.3 0.14 0.62 0.21 0.62 1 0.65 0.37 0.58 0.58 0.55 0.14 0.58 0.57 0.32 0.13 b 0.0001* b 0.0001* 0.24 0.001* 0.003* 0.156 0.01* 0.006* 0.72 0.11 0.01* 0.008* 0.017* 0.017* 0.72 0.21

PCI = percutaneous coronary intervention; CAD = coronary artery disease; MEStot = overall amount of microembolic signal; MESinj = microembolic signal during contrast medium injections; MESman = microembolic signal during catheters manipulation; MES exch = microembolic signal during catheters exchange; MEScor = microembolic signal during coronary ostia engagement; RMCA = right middle cerebral artery; LMCA = left middle cerebral artery; values are numbers (%), amean ± SD or b median (interquartile range); cserum creatinine concentration N 2 mg/dL, * p b 0.05.

Surprisingly, the single catheter strategy reduced total rate of MES and amount related to catheter exchanges not only in the right but also in the left MCA, where instead no differences should be expected. This excess of microemboli into the left MCA when using Judkins catheter could be explained simply by the greater number of microemboli spread into the general circulation or, alternatively, by the presence of bovine-type arch in a part of our study population. In this type of aortic arch (present in up to 20% of general population [8]) both common carotid arteries arise from the innominate artery, with consequent risk of cerebral embolization to both cerebral hemispheres when using a right transradial approach. Unfortunately, we 0167-5273/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijcard.2013.11.054

Fig. 1. Occurrence of MES according to coronary angiography stages - line represents the median, box represents the interquartile range, bar minimum–maximum; * p b 0.05.

did not perform routinely angiography of supraaortic vessels, and we don't know the proportion of patients in our study with this anatomic variant. MES are usually clinically silent and are not proof of cerebral damage, since relation to new MRI lesions and cognitive dysfunction is weak [1]. However, MES have been used as endpoint in trials comparing effectiveness of protection devices during carotid artery stenting and they could be considered as an appropriate marker of cerebral embolization [9]. TCD is extremely useful to understand mechanisms of cerebral embolization during endovascular procedures, clarifying which steps of a procedure generate more microemboli [10]. References [1] Lund C, Bang Nes R, Pynten Ugelstad T, et al. Cerebral emboli during left heart catheterization may cause acute brain injury. Eur Heart J 2005;26:1269–75. [2] Pacchioni A, Versaci F, Mugnolo A, et al. Risk of brain injury during diagnostic coronary angiography: comparison between right and left radial approach. Int J Cardiol 2013;167(6):3021–6. [3] Jurga J, Nyman J, Tornvall P, et al. Cerebral microembolism during coronary angiography: a randomized comparison between femoral and radial arterial access. Stroke 2011;42:1475–7. [4] Hoffman SJ, Routledge HC, Lennon MZ, et al. Procedural factors associated with percutaneous coronary intervention-related ischemic stroke. J Am Coll Cardiol Intv 2012;5:200–6. [5] Bertrand OF, Rao SV, Pancholy S, et al. Transradial approach for coronary angiography and interventions. Results of the First International Transradial Practice Survey. J Am Coll Cardiol Intv 2010;3:1022–31. [6] Kim SM, Kim DK, Kim DI, Kim DA, Joo SJ, Lee JW. Novel diagnostic catheter specifically designed for both coronary arteries via the right transradial approach. A prospective, randomized trial of Tiger II vs Judkins catheters. Int J Cardiovasc Imaging 2006;22(3–4):295–303. [7] Kanei Y, Nakra NC, Liou M, et al. Randomized comparison of transradial coronary angiography via right or left radial artery approaches. Am J Cardiol 2011;107:195–7. [8] Layton KF, Kallmes DF, Cloft HJ, Lindell EP, Cox VS. Bovine aortic arch variant in humans: clarification of a common misnomer. Am J Neuroradiol 27:1541-42. [9] Montorsi P, Caputi L, Galli S, et al. Microembolization during carotid artery stenting in patients with high-risk, lipid-rich plaque. A randomized trial of proximal versus distal cerebral protection. J Am Coll Cardiol 2011 Oct 11;58(16):1656–63. [10] Drews T, Pasic M, Buz S, et al. Transcranial Doppler sound detection of cerebral microembolism during transapical aortic valve implantation. Thorac Cardiovasc Surg 2011;59(4):237–42.