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Introduction: Left ventricular ejection fraction (EF) ≤ 35% is the cornerstone criterion for implantable cardioverter-defibrillator (ICD) eligibility. Improvement in EF may occur in ICD-eligible patients after coronary artery bypass graft surgery (CABG). However, the incidence, predictors, and outcomes of this process are unclear., Methods and Results: We studied 427 patients with EF ≤ 35% who underwent CABG in the Surgical Treatment for Ischemic Heart Failure (STICH) trial and had a systematic pre- and postoperative (4 months) EF assessment using the identical cardiac imaging modality. All imaging studies were interpreted at a core laboratory. Improvement in EF was defined as postoperative EF > 35% and >5% absolute improvement from baseline. Of the 427 patients (mean age 61.8 ± 9.5 and 50 women), 125 (29.2%) had EF improvement. Their mean EF increased from 26.8% (±5.8%) to 43.3% (±6.5%) (p < .0001). EF improvement occurred in only 20% of patients with a preoperative EF < 25%. The odds of EF improvement were 1.96 times higher (95% confidence interval [CI]: 0.91-4.23, p = .09) in patients with myocardial viability. In adjusted analyses, EF improvement was associated with a significantly lower risk of all-cause mortality (hazard ratio [HR]: 0.58, 95% CI: 0.35-0.96; p = .03) and heart failure mortality (HR: 0.31, 95% CI: 0.11-0.87; p = .027)., Conclusion: Nearly 1/3rd of ICD-eligible patients undergoing CABG had significant improvement in EF, obviating the need for primary prevention ICD implantation. These results provide patients and clinicians data on the likelihood of ICD eligibility after CABG and support the practice of reassessment of EF after revascularization., (© 2021 Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Objective: Examine the trajectory of left ventricular ejection fraction (EF) among patients eligible for implantable cardioverter-defibrillator (ICD) therapy., Background: EF is the cornerstone criterion for ICD therapy, but the risk of sudden cardiac death remains after an improvement in EF., Methods: We examined the trajectory of EF among 1178 participants of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) who had three or more assessments of EF, at least 90 days apart. A follow-up EF > 35% or >10% absolute increase in EF from baseline were examined as the criteria for EF improvement., Results: At first follow-up, 381 (32%) patients had an improvement of EF to >35%. However, EF had returned back to ≤35% in 109 (27%) of these patients at second follow-up. Similarly, 446 (38%) patients experienced a >10% improvement in EF at first follow-up, but 109 (24%) of these had a subsequent >10% decrease in EF at the second follow-up. Of the 32 patients with normalized EF (≥55%) at first follow-up, 18 (56%) had a subsequent >10% decrease in EF. The fluctuation in EF was present in both ischemic and nonischemic cardiomyopathy but a higher proportion of patients with nonischemic cardiomyopathy had an improvement in EF to >35% at first follow-up compared to those with ischemic cardiomyopathy (38% vs. 27%, p = < .0001)., Conclusion: There is substantial fluctuation of EF among patients who are eligible for ICD therapy., (© 2021 Wiley Periodicals LLC.)

Purpose: Bifascicular block and prolonged PR interval on the electrocardiogram (ECG) have been associated with complete heart block and sudden cardiac death. We sought to determine if cardiac implantable electronic devices (CIED) improve survival in these patients., Methods: We assessed survival in relation to CIED status among 636 consecutive patients with bifascicular block and prolonged PR interval on the ECG. In survival analyses, CIED was considered as a time-varying covariate., Results: Average age was 76 ± 9 years, and 99% of the patients were men. A total of 167 (26%) underwent CIED (127 pacemaker only) implantation at baseline (n = 23) or during follow-up (n = 144). During 5.4 ± 3.8 years of follow-up, 83 (13%) patients developed complete or high-degree atrioventricular block and 375 (59%) died. Patients with a CIED had a longer survival compared to those without a CIED in the traditional, static analysis (log-rank p < 0.0001) but not when CIED was considered as a time-varying covariate (log-rank p = 0.76). In the multivariable model, patients with a CIED had a 34% lower risk of death (hazard ratio 0.66, 95% confidence interval 0.52-0.83; p = 0.001) than those without CIED in the traditional analysis but not in the time-varying covariate analysis (hazard ratio 1.05, 95% confidence interval 0.79-1.38; p = 0.76). Results did not change in the subgroup with a pacemaker only., Conclusions: Bifascicular block and prolonged PR interval on ECG are associated with a high incidence of complete atrioventricular block and mortality. However, CIED implantation does not have a significant influence on survival when time-varying nature of CIED implantation is considered.