Prevalence and predictors of pacing-induced cardiomyopathy in young adult patients (<60 years) with pacemakers.

INTRODUCTION

Clinical trials and observational studies of pacing-induced cardiomyopathy (PICM) have largely included elderly patients with mean age >70 years. The prevalence and predictors of PICM in younger patients (age < 60 years) after pacemaker implantation are not known.

METHODS

Adults (18-59 years) who received single-chamber ventricular or dual-chamber pacemakers at Vanderbilt University Medical Center from 1986 to 2015 were included. Patients without documented ventricular pacing burden and patients with baseline left ventricular ejection fraction (LVEF) <35% were excluded. PICM was defined as LVEF decrease of ≥ 10% and LVEF < 50% during follow-up with right ventricular pacing ≥20%, and without alternative explanations for cardiomyopathy.

RESULTS

A total of 325 patients were included in the study. During a median follow-up duration of 11.5 (Interquartile range 7-17) years, 38 patients (11.7%) developed PICM (1.3 per 100 patient-year). Older age (HR 2.5 for age ≥50 years, p = .013), reduced baseline LVEF (HR 2.4, p = .022), and preimplant AVB (HR 2.7, p = .007) were associated with an increased risk of PICM in the multivariate analysis. Furthermore, baseline AF conferred an increased risk of PICM only in patients without preimplant AVB but not patients with pre-implant AVB.

CONCLUSIONS

The incidence of PICM in young patients was low, but PICM could occur more than a decade after pacemaker implantation. Older age, baseline reduced LVEF, and preimplant AVB were associated with an increased risk of PICM in the young patient cohort.