© 2014, Wiley Periodicals, Inc. DOI: 10.1111/echo.12652

Echocardiography

The Evaluation of Preoperative Right Ventricular Diastolic Dysfunction on Coronary Artery Disease Patients with Left Ventricular Dysfunction Yan Jin, M.D., Ph.D., Huishan Wang, M.D., Ph.D., Zengwei Wang, M.D., Hui Jiang, M.D., Ph.D., Dengshun Tao, M.D., Ph.D., and Haibo Wu, M.D., Ph.D. Department of Cardiac Surgery, General Hospital of Shenyang Military Area Command, Shenyang City, China

Objective: Early death following coronary artery bypass graft (CABG) surgery tends to occur in coronary heart disease (CHD) patients with significantly decreased left ventricular function. Methods: The clinical data of 231 patients with preoperative left ventricular ejection fraction (LVEF) ≤35% who underwent CABG were retrospectively analyzed from June 2007 to October 2012. The patients were divided into 2 groups: group A contained 39 patients who suffered early postoperative death and group B contained 192 patients who had a successful CABG outcome. Results: Multivariate analysis demonstrated that only significantly decreased preoperative right ventricular (RV) diastolic function (increase in Et/Et0 ) and lack of suitable target bypass vessels were independent risk factors for early death after CABG surgery in patients with severely impaired left ventricular function (P = 0.003 and 0.002, respectively). Other factors, including age, intra-aortic balloon pump (IABP) implantation, ischemic mitral regurgitation (IMR) treatment, left atrial internal diameter, and end-diastolic left ventricular internal diameter, were not associated with early death following CABG. Preoperative Et/Et0 ≥10 was significantly associated with early death after CABG in patients with severely impaired left ventricular function (v2 = 11.55, P < 0.001, odds ratio [OR] = 17.54, 95% confidence interval [CI]: 2.12–383.16). Conclusion: Decreased preoperative RV diastolic function and lack of suitable target bypass vessels are independent risk factors for early death following CABG in patients with severely impaired left ventricular function. Therefore, assessment of preoperative RV diastolic function will be helpful in predicting early death after CABG in these patients. Additionally, Et/Et0 ≥10 is significantly associated with early death after CABG. (Echocardiography 2014;31:1259–1264) Key words: coronary artery bypass graft surgery (CABG), right ventricular function, echocardiography, left ventricular ejection fraction Coronary artery bypass graft (CABG) surgery is the standard treatment for severe disease of all 3 major coronary arteries and left main coronary artery disease (CAD).1 Reduced left ventricular systolic function is one of the main risk factors for early and late death following CABG.2,3 There is a marked increase in postoperative complications and mortality following CABG in patients with significantly decreased preoperative left ventricular ejection fraction (LVEF).4,5 A randomized clinical study6 of all-cause mortality for CAD patients with preoperative LVEF ≤35% demonstrated that there was no significant difference between patients who received medication treatment alone and those who received medication and CABG combination therapy.

However, the cardiovascular mortality and hospitalization rates of the patients treated with combination therapy were relatively lower. In CAD patients with significantly decreased LVEF, left ventricular function is improved only to a limited extent with CABG surgery,7 and the mortality rate is relatively higher. Therefore, appropriate preoperative evaluation is necessary when choosing a treatment regimen with an optimal risk– benefit ratio, so as to increase the success rate of CABG. Patients with significantly decreased preoperative left ventricular function who underwent CABG at our hospital were included in the present study, which was performed to determine the risk factors (apart from LVEF) for early death following CABG (death within 1 month after surgery).

Address for correspondence and reprint requests: Yan Jin, M.D., Ph.D., Cardiac Surgery in Cardiovascular Institute and General Hospital of Shenyang Military Area Command, Shenyang City, Liaoning Province, 110016, China. Fax: 86024-23912376; E-mail: [email protected]

Subjects and Methods: Subjects: A total of 2613 consecutive patients underwent CABG at the Division of Cardiovascular Surgery of our hospital from June 2007 to October 2012. 1259

Jin, et al.

Among these patients, 177 had valvular heart disease and coronary heart disease (CHD), and the remaining 2436 patients underwent surgery only for CHD. A total of 231 (9.5%) of 2436 CHD patients with preoperative LVEF ≤35% were included in this study. These patients all had severe disease of all 3 major coronary arteries, and 57 (2.3%) also underwent mitral valve surgery for chronic ischemic mitral regurgitation (CIMR). A case–control study design was used to retrospectively analyze the clinical data of these patients, including age, sex, disease duration, complications, liver and kidney function, intraaortic balloon pump (IABP) implantation, echocardiographic parameters, the number of suitable target bypass arteries, and IMR treatment. Surgery: Complete revascularization was one of the goals of the CABG surgery. The number of bypasses was determined through review of the preoperative coronary angiogram (Philips Ultrasound Corp., Bothell, WA, USA) and intraoperative examination of the coronary arteries. The internal thoracic artery was anastomosed to the left anterior descending coronary artery. For other major branches, end-to-side anastomosis and/or sequential anastomosis of the harvested great saphenous vein or radial artery to the distal end of the coronary artery was performed, and then the proximal end of the graft was anastomosed to the ascending aorta. The coronary arteries with the distal portion beyond the lesion greater than 1 mm in diameter were used for the bypasses. The procedures were performed by 2 experienced surgeons capable of achieving high-quality anastomoses. All procedures were performed by the same cardiac anesthesiologist, perfusionist, and surgeons. The grade of the CIMR was determined using preoperative echocardiography (Philips). A resting effective regurgitant orifice (ERO) area of >20 mm2 was the definition for moderate-tosevere CIMR. For patients with moderate-tosevere CIMR, mitral valvuloplasty or mitral valve replacement was performed as well. CABG surgery alone was performed without cardiopulmonary bypass while the heart remained beating. When stable circulation could not be achieved with medications during off-pump CABG, onpump procedures were performed. The combination of CABG with mitral valve surgery was performed with moderately hypothermic cardiopulmonary bypass while the heart was not beating. IABP was performed for patients experiencing preoperative acute left heart failure and/ or unstable angina, and also for those experiencing unstable blood flow dynamics at the end of the surgery or after surgery. 1260

Echocardiography: Philips iE33 color Doppler ultrasound equipment (Philips) was used, which had a transducer with a frequency range of 1–5 MHz. The following twodimensional measurements were acquired: left atrial diameter (LAD), left ventricular end-diastolic internal diameter (LVEDI), left ventricular endsystolic internal diameter (LVESI), right ventricular outflow tract end-diastolic diameter (RVOTD), end-systolic septal-lateral mitral annular diameter (SL), and left ventricular wall motion score index (LVWMI). Mitral annular dilatation was defined as an SL of ≥33 mm. None of the study patients had an organic mitral valve lesion; therefore, IMR was considered. The ERO was used for the evaluation of the grade of MR,8 with an ERO of ≥20 mm2 indicating severe MR, 10–19 mm2 indicating moderate MR, and 1–9 mm2 indicating mild MR. The LVEF, left ventricular end-diastolic and end-systolic volume (LVEDV and LVESV) was measured using Simpson’s method,9 and an LVEF of ≥0.50 was considered normal. The peak earlyand late-diastolic flow velocities across the mitral and tricuspid valve orifices were measured (Em, Et, Am, and At) with pulsed-wave (PW) Doppler imaging and four-chamber apical view. Then, the Em/Am and Et/At values were calculated. PW-TDI was used to measure the peak early- and late-diastolic velocities and peak systolic velocity at the lateral mitral annulus (Em0 , Am0 , and Sm0 ), the interventricular septal annulus (Ei0 , Ai0 , and Si0 ), and the lateral tricuspid annulus (Et0 , At0 , and St0 ). The Em/Em0 , Em/Ei0 , and Et/Et0 values were calculated.10,11 And tricuspid annular plane systolic excursion (TAPSE) was measured at the lateral tricuspid annulus with M-mode. The right ventricular systolic pressure (RVSP) was calculated based on the tricuspid regurgitation spectrum using the following equation: RVSP = 4 9 V2 + P, where V is the tricuspid regurgitation peak velocity and P is the right atrial pressure (10 mmHg). No patient had pulmonary stenosis, thus RVSP was considered equal to pulmonary artery systolic pressure (PASP). For patients with atrial fibrillation, data acquisition was taken during 600–1000 ms of the cardiac cycle. The final results were calculated based on the average of 3 continuous cardiac cycle measurements. All data acquisition was performed at the end of expiration. The flow velocities across the mitral and tricuspid valve orifices with PW and the peak velocity at the mitral and tricuspid valve annulus with PW-TDI is clinically feasible and reproducible, and are used to evaluate left and right ventricular (RV) systolic and diastolic function sensitively.11,12 So these indexes were measured in each patient at our institution as part of the routine clinical protocol and not just as a research tool. But right ventricular myocardial performance index

Preoperative RV Diastolic Dysfunction on CAD Patients

(RVMPI), RV fraction area change (RVFAC), and RV strain were not routinely measured in each patient due to the nature of the relatively intricate measurements. Statistical Analysis: The Statistical Package for the Social Sciences (SPSS) version 11.0 software (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. A case– control study design was used to retrospectively analyze the clinical data of groups A and B. Comparisons of age and the echocardiographic parameters (internal diameters, PASP, LVWMI, LVEF, grade of MR, etc.) between the groups were performed using t-tests. Comparisons of the sex ratio and incidence of complications between the groups were performed using v2 tests. All variables with P < 0.1 were included in a multivariate logistic regression to determine the risk factors for early death after CABG surgery in patients with severely impaired left ventricular function. A P-value 6 or >8. One hundred fifty-one (54.5%) patients in this study had Et/Et0 >8; therefore, among the CAD patients with severely impaired left ventricular function, over half had decreased preoperative RV diastolic function. The present study also demonstrated that a significant decrease in RV diastolic function could be used as a predictor of an increased rate of early postoperative death in patients with significantly decreased preoperative left ventricular function. In other words, patients with a preoperative Et/Et0 ≥10 tend to suffer early postoperative death (v2 = 11.55, P < 0.001, OR = 17.54, 95% CI: 2.12–383.16). The risks of early postoperative death in these patients with a preoperative Et/Et0 ≥10 was 17-fold higher than that in patients with Et/Et0

The evaluation of preoperative right ventricular diastolic dysfunction on coronary artery disease patients with left ventricular dysfunction.

Early death following coronary artery bypass graft (CABG) surgery tends to occur in coronary heart disease (CHD) patients with significantly decreased...
68KB Sizes 0 Downloads 4 Views