Clinical outcomes and left ventricular systolic function changes after right ventricular pacing in patients with complete atrioventricular block

Background: Permanent pacemakers are routinely used to treat patients with complete atrioventricular block. However, as patient characteristics and treatment concepts have changed, little is known about clinical outcome and echocardiographic changes in a real-world cohort of patients with complete atrioventricular block after right ventricular pacing. Methods: Patients with first-time permanent pacemaker implantation due to complete atrioventricular block were enrolled between January 1, 2011, and June 30, 2020, with all-cause death and hospitalization for heart failure as study endpoints, and changes in left ventricular systolic function during follow-up were analyzed. Results: A total of 460 patients were enrolled, with an average age of 69.9 +/- 12.4 years. The mean left ventricular ejection fraction (LVEF) was 57.71 +/- 12.63%. Fifty-five patients (12.0%) had an LVEF below 50%. The median follow-up time was 50.7 (26.2, 80.5) months, and the event-free survival rate was 91.3% for all-cause death and 85.4% for heart failure hospitalization. During follow-up, 90.1% of patients with preoperative LVEF 50% had a normal left ventricular function. Multivariate analysis showed that each percentage increment in LVEF was associated with a 3% (95% CI, 1-5%) reduction in heart failure hospitalization, whereas RV pacing percentage was a predictor of heart failure hospitalization (HR, 1.053; 95% CI 1.012-1.096). Conclusion: Permanent pacemaker implantation provided a favorable clinical prognosis in a population where most patients retained left ventricular function with complete atrioventricular block.