Incidence of 'Pacing induced cardiomyopathy': An observational study

Background Right ventricular pacing (RVP) is the main treatment of symptomatic bradycardia. But it is well established that cardiac pacing induces electrical and mechanical left ventricular dyssynchrony. Purpose Evaluate the effect of RVP on the incidence of heart failure (HF) in patients implanted for symptomatic bradycardia. Methods The study was prospective, observational, including all consecutive patients implanted in our center between 2009 January and 2014 December for symptomatic bradycardia. HF diagnosis was based on clinical data, natriuretic peptides dosage and echocardiography. The follow up was done every 6 months. The cumulative HF rates were estimated using the Kaplan-Meier method, and variables associated with the risk of HF were identified by the Cox model. Results We included 986 patients, with a mean age of 74.6 ± 8.3 years, and 58.6% of men. A total of 675 (68.4%) had a second or third atrioventricular block and the others a sinus node dysfunction. The proportions of NYHA class I, II, III and IV at inclusion were 28.6%, 49.7%, 17.4% and 4.3% respectively. The mean left ventricular ejection fraction (LVEF) was 0.51 ± 0.10. After a median follow-up of 47.8 months, the cumulative rate of HF was 13.6% (CI 95%: 11.2%–16.0%). Predictive factors of HF occurrence were NYHA class (HR: 3.08; CI 95%: 2.45–4.41, for class II to IV versus class I); history of HF (HR: 2.10; CI 95%: 1.60–2.90); LVEF (HR: 2.13; CI 95%: 1.56–3.02, for LVEF ≤ 0.40 versus > 0.40); history of atrial fibrillation (HR: 1.48; CI 95%: 1.1–2.25); the percentage of ventricular pacing (HR: 3.26; CI 95%: 2.11–5.43; for %VP ≥ 90% versus Conclusions RVP is independently associated with the risk of HF. Using algorithms minimizing unnecessary RVP and cardiac resynchronization therapy in some cases could reduce the incidence of the “pacing induced cardiomyopathy”.