Severe Left Ventricular Dyssynchrony Is Associated With Poor Prognosis in Patients With Moderate Systolic Heart Failure Undergoing Coronary Artery Bypass Grafting

Abstract

ObjectivesThe objective of the present study was to assess the relationship between the presence of left ventricular (LV) dyssynchrony and clinical outcome in patients with moderate systolic heart failure undergoing coronary artery bypass graft (CABG) surgery.BackgroundThe presence of LV dyssynchrony is associated with poor prognosis in patients with LV dysfunction.MethodsThe study consisted of 215 consecutive patients with ischemic cardiomyopathy and dyspnea (age 65 ± 9 years, 81% male) undergoing CABG. Dyssynchrony was calculated by tissue Doppler imaging from regional time intervals in basal LV segments before and 1 month after CABG. Myocardial viability was assessed using single-photon emission computed tomography (SPECT) before CABG.ResultsTwenty-five patients (11.6%) died within 30 days (in-hospital mortality) of CABG. The presence of pre-CABG dyssynchrony ≥119 ms had the highest predictive accuracy for in-hospital mortality, with a sensitivity of 84% and a specificity of 71%. During the median follow-up period of 359 days (interquartile range 219 to 561), an additional 19 patients (10.3%) died and 34 patients (18.5%) were hospitalized for worsening heart failure. At Cox regression analysis, post-CABG dyssynchrony ≥72 ms and ≥5 viable segments were identified as independent predictors of clinical events, with a hazard ratio (HR) of 5.02, 95% confidence interval (CI) 2.57 to 10.02 (p < 0.001), and an HR of 0.63, 95% CI 0.55 to 0.75 (p < 0.001), respectively. Patients without post-CABG dyssynchrony and with viable myocardium had excellent prognosis compared with patients with severe post-CABG dyssynchrony and nonviable myocardium (event rate 3% vs. 64%; p < 0.001).ConclusionsThe presence of severe LV dyssynchrony is associated with poor clinical outcomes despite revascularization. These results advocate a routine assessment of both LV dyssynchrony and viability to predict outcome in systolic heart failure patients undergoing CABG surgery