The Effect of Elapsed Time from Myocardial Infarction on Mortality and Major Adverse Cardiac and Cerebro, vascular Events in ICD Patients

Background Despite the effectiveness of implantable cardioverter defibrillator (ICD) therapy in reducing mortality, the optimal timing of ICD implantation after myocardial infarction (MI) remains inconclusive. The aim of this study is to evaluate the association of elapsed time from MI to ICD implantation on mortality and major adverse cardiac and cerebro, vascular events (MACCEs) in patients with prior MI.
Methods We studied 974 patients who underwent a first ICD implantation between October 1998 and August 2011. The median time from MI to ICD implantation was 7.2 years. Elapsed time from MI to ICD was categorized into tertiles (<2.5 years, 2.5-12.1 years, >12.1 years). Additionally, the time from most recent MI to ICD implantation was dichotomized at 18 months.
Results During a median follow-up of 3.4 years, 287 patients died. Cumulative mortality rates at 3 years, 5 years, and 8 years were 19%, 29%, 47%, respectively. In univariate analysis, there was a significant difference in mortality for patients in the highest tertile compared to those in the lowest tertile (hazard ratio: 1.50; 95% confidence interval: 1.12-2.02; P = 0.007). After adjusting for baseline characteristics, there was no association between time from MI and mortality. At 8-year follow-up, the cumulative MACCE rate excluding mortality was 22%. No association between time from MI and MACCE was found.
Conclusion In this study, we found no association between the elapsed time from MI to ICD implantation and 8-year all-cause mortality or MACCE in post-MI ICD patients.