Pacemaker dependency after isolated aortic valve replacement: do conductance disorders recover over time?

Permanent pacemaker (PPM) implantation is required in 3-8% of all patients undergoing aortic valve replacement (AVR). Our aim was to evaluate long-term PPM dependency and recovery of atrioventricular (AV) conduction disorders during follow-up in these patients. Since January 1997, a total of 2106 consecutive patients underwent isolated AVR at our institution. Of these, 138 patients (6.6%, 72 female, median age 71 (37-89) years) developed significant conduction disorders leading to PPM implantation postoperatively. Preoperative ECG showed normal sinus rhythm (n = 64), first degree AV block (n = 19), left bundle branch block (n = 13), right bundle branch block (n = 16), left anterior hemiblock (n = 14) and AV block with ventricular escape rhythm (n = 10). Atrial fibrillation was present in 23 patients. Pacemakers were implanted after a median of 7 (1-30) days following AVR. PPM dependency was analysed by ECG and pacemaker check during follow-up. A total of 45 of 138 patients with postoperative PPM Implantation died during a mean follow-up time of 5.3 +/- 4.7 years. A further 9 patients were lost to follow-up. Long-term survivals at 1, 5 and 10 years were 88%, 79% and 59%, respectively. Only 8 (10%) of 84 survivors were no longer pacemaker-dependent. The majority of patients (n = 66, 79%) required permanent ventricular stimulation, and the remaining 10 (13%) showed intermittent stimulation with a mean ventricular stimulation fraction of 73% (22-98%). The majority of patients do not recover from AV conduction disorders after AVR. Since higher-grade AV blocks expose patients to a high risk of sudden death after surgery, we recommend early implantation of permanent pacemaker.