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OBJECTIVES: This study evaluated the long-term risk of permanent pacemaker implantation following Cox-maze IV (CMIV) and concurrent mitral valve surgery.

METHODS: A retrospective, nationwide, registry-based analysis was conducted on postoperative permanent pacemaker implantation in 397 patients with symptomatic mitral valve insufficiency and atrial fibrillation who underwent CMIV and mitral valve surgery in Sweden between 2009 and 2017. They were compared to a registry group of 346 patients with atrial fibrillation who underwent mitral valve surgery without surgical ablation during 2014–2017. The follow-up ended on 30 September 2022.

RESULTS: CMIV patients were on average 4 years younger and had lower surgical risk than registry patients. More CMIV patients underwent early (<30 days) pacemaker implantation (13.3% vs. 5.5%, P = 0.002). CMIV patients had a doubled adjusted risk of requiring a pacemaker compared to registry patients after 8 years [HR 1.96, 95% CI 1.27–3.04]. In the CMIV group, 22% (95% CI 18–26%) had a pacemaker by 5 years, increasing to 27% (95% CI 22–31%) by 8 years, compared to 13% (95% CI 10–17%) at both time intervals in the registry group. Atrioventricular block II/III accounted for >60% of early pacemaker indications in both groups, and sinus node dysfunction was the indication for late pacemaker implantation in 48% in the CMIV group.

CONCLUSIONS: Patients undergoing CMIV concomitant with mitral valve surgery have a higher rate of postoperative pacemaker implantation compared to patients with atrial fibrillation undergoing mitral valve surgery alone. Sinus node dysfunction was the main indication for late pacemaker among CMIV patients.