Dual chamber versus single chamber pacemaker in patients in sinus rhythm with an atrioventricular block: a nationwide cohort study

Background In complete atrioventricular block (AVB) with underlying sinus rhythm, it is recommended to implant a dual-chamber pacemaker rather than a single-chamber pacemaker. However, no large-scale study has been able to demonstrate the superiority of this choice on hard clinical criteria such as morbimortality. Methods This retrospective observational study included all patients who received a primary pacemaker implantation in the indication of complete AVB with underlying sinus rhythm in France, based on the national administrative database between January 2013 and December 2022. Results After propensity score matching, we obtained two groups containing 19,219 patients each. The incidence of all-cause mortality was 9.22%/year for the dual-chamber pacemaker group, compared with 11.48%/year for the single-chamber pacemaker group (HR 0.807, p<0.0001). Similarly, there was a lower incidence of cardiovascular mortality (HR 0.766, p<0.0001), heart failure (HR 0.908, p<0.0001), atrial fibrillation (HR 0.778, p<0.0001) and ischemic stroke (HR 0.873, p=0.008) in the dual-chamber pacemaker group than in the single-chamber pacemaker group. Regarding reinterventions and complications, there were fewer upgrades (addition of atrial lead or left ventricular lead) in the dual chamber group (HR 0.210, p<0.0001), but more hematomas (HR 1.179, p=0.006) and lead repositioning (HR 1.123, p=0.04). Conclusion In the indication of complete AVB with underlying sinus rhythm, our results are consistent with current recommendations to prefer implantation of a dual-chamber pacemaker rather than a single-chamber pacemaker for these patients. Implantation of a dual-chamber pacemaker is associated with a lower risks of mortality, heart failure, atrial fibrillation, and stroke during follow-up.