Advertisement

Ventricular Arrhythmias Following Coronary Artery Bypass Grafting for Ischemic Cardiomyopathy: When to insert an implanted cardiac defibrillator?

Open AccessPublished:November 15, 2022DOI:https://doi.org/10.1016/j.xjon.2022.10.012
      This paper is only available as a PDF. To read, Please Download here.

      Abstract

      Objectives

      To determine the incidence, predictors, and clinical impact of ventricular arrhythmias (VAs) following coronary artery bypass grafting (CABG) and to evaluate the impact of implantable cardioverter-defibrillator (ICD) on the survival of patients with VAs.

      Methods

      We enrolled 498 patients with left ventricular (LV) ejection fraction ≤40% who underwent CABG between 1993 and 2015. Clinical follow-up was completed in 94.0% of patients, with a median follow-up of 58.4 months.

      Results

      Overall, 212 patients (43%) died, mainly due to heart failure (n=54, 10.8%) or sudden cardiac death (SCD) (n=40, 8.0%). The SCD rate was highest during the first six months, with a monthly rate of 0.37%. Overall, 99 patients (20%) developed postoperative VAs, while ICD implantation was performed in 55 patients. Previous VAs (hazard ratio [HR] 3.22; 95% confidence interval [CI] 1.98-5.24; P<.001), LV end-systolic dimension (HR 1.07; 95%CI 1.04-1.10; P<.001), and prior myocardial infarction in the left anterior descending artery (LAD) territory (HR 1.73; 95%CI 1.10-2.73; P=.02) were independent predictors of postoperative VAs. Notably, the 5-year survival rate of patients with VAs who received ICD implantation was significantly higher than that of patients with VAs who did not receive it (76.1% versus 22.7%, P<.001) and was comparable to that of patients without VAs (76.1% versus 73.6%, P=.93).

      Conclusions

      SCD affects a significant proportion of patients with ischemic cardiomyopathy undergoing CABG, most frequently within three months postoperatively. In order to prevent SCD, earlier ICD implantation should be indicated for high-risk patients with scars in the LAD territory and excessive LV remodeling.

      Keywords

      Glossary of Abbreviations:

      SCD (sudden cardiac death), VAs (ventricular arrhythmias), ICM (ischemic cardiomyopathy), CABG (coronary artery bypass grafting), ICD (implantable cardioverter-defibrillator), LV (left ventricular), ITA (internal thoracic artery), LAD (left anterior descending artery), SVR (surgical ventricular restoration), MR (mitral regurgitation), VF (ventricular fibrillation), VT (ventricular tachycardia), IQR (interquartile range), HR (hazards ratio), CI (confidence interval), IABP (intra-aortic balloon pumping)