The Effect of Medical Therapy on Reducing the Risk of Pacing Induced Cardiomyopathy

Background: High right ventricular (RV) pacing burden can result in pacing-induced cardiomyopathy (PICM). Objectives: To investigate whether ACE inhibitors (ACEI), angiotensin receptor blockers (ARB), and beta blockers (BB) reduce the risk of PICM in patients with high RV pacing burden. Methods: This was a single center, retrospective study which included patients with normal ejection fraction (EF) and complete heart block who underwent pacemaker implantation between 1992 and 2013. The medical therapy group included patients who received ACEI/ARB, BB, or combination of these classes. The control group received neither ACEI/ARB nor BB. The primary endpoint was PICM, defined as upgrade to a biventricular device or reduction in EF to ?40% without another etiology identified. Fine-Gray subdistribution hazard models accounting for death as a competing risk were used to determine the relationship between medical therapy (ACEI/ARB, BB, or combination) and cumulative incidence of PICM. Results: The study included 642 patients (mean [SD] age 71 [14] years; 51% women). Over 10 years of follow-up, 76 (11.8%) patients received ACEI/ARB therapy only; 49 (7.6%) received BB therapy only; and 86 (13.4%) were exposed to both. PICM occurred in 10 of 211 patients in the medical therapy group (4.7%) and in 30 of 431 in the control group (7.0%). In adjusted analyses weighted for group-switching, the risk of PICM was significantly lower in the medical therapy group compared to the control group (HR 0.59, 95% CI 0.45 - 0.77). Patients exposed to combination therapy had the lowest risk (HR 0.46, 95% CI 0.31 - 0.69). Conclusion: In patients with high RV pacing burden, BB therapy alone or in combination with ACEI/ARBs appears to reduce the risk of PICM within 10 years of pacemaker implantation.