Pacemaker Implantation After Mitral Valve Surgery With Atrial Fibrillation Ablation

Abstract

Background: The incidence of permanent pacemaker (PPM) implantation is higher following mitral valve surgery (MVS) with ablation for atrial fibrillation (AF) compared with MVS alone.

Objectives: This study identified risk factors and outcomes associated with PPM implantation in a randomized trial that evaluated ablation for AF in patients who underwent MVS.

Methods: A total of 243 patients with AF and without previous PPM placement were randomly assigned to MVS alone (n = 117) or MVS + ablation (n = 126). Patients in the ablation group were further randomized to pulmonary vein isolation (PVI) (n = 62) or the biatrial maze procedure (n = 64). Using competing risk models, this study examined the association among PPM and baseline and operative risk factors, and the effect of PPM on time to discharge, readmissions, and 1-year mortality.

Results: Thirty-five patients received a PPM within the first year (14.4%), 29 (83%) underwent implantation during the index hospitalization. The frequency of PPM implantation was 7.7% in patients randomized to MVS alone, 16.1% in MVS + PVI, and 25% in MVS + biatrial maze. The indications for PPM were similar among patients who underwent MVS with and without ablation. Ablation, multivalve surgery, and New York Heart Association functional (NYHA) functional class III/IV were independent risk factors for PPM implantation. Length of stay post-surgery was longer in patients who received PPMs, but it was not significant when adjusted for randomization assignment (MVS vs. ablation) and age (hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.61 to 1.08; p = 0.14). PPM implantation did not increase 30-day readmission rate (HR: 1.43; 95% CI: 0.50 to 4.05; p = 0.50). The need for PPM was associated with a higher risk of 1-year mortality (HR: 3.21; 95% CI: 1.01 to 10.17; p = 0.05) after adjustment for randomization assignment, age, and NYHA functional class.

Conclusions: AF ablation, multivalve surgery, and NYHA functional class III/IV were associated with an increased risk for permanent pacing. PPM implantation following MVS was associated with a significant increase in 1-year mortality. (Surgical Ablation Versus No Surgical Ablation for Patients With Atrial Fibrillation Undergoing Mitral Valve Surgery; NCT00903370).

Keywords: biatrial maze; cardiac surgery; permanent pacemaker; pulmonary vein isolation; valvular heart disease.

Central Illustration.. Permanent Pacemaker (PPM) Placement and Survival.

Extended Kaplan-Meier curve assessing the effect of PPM on survival probability using method by Snappin et al. (12). Median observation time was 1.3 (IQR, 0.4, 3.4) months for patients who died. Abbreviations: PPM, permanent pacemaker.

Figure 1.. Cumulative Incidence of PPM Placement by Randomization Assignment.

Nonparametric estimates of the cumulative incidence functions for permanent pacemaker implantation with death as a competing risk over 12 months after mitral-valve surgery ± concomitant ablation procedure. Abbreviations: CI, confidence interval; MVS, mitral-valve surgery; PPM, permanent pacemaker; PVI, pulmonary-vein isolation.

Figure 2.. Patient and Procedure Characteristics Associated with PPM Placement.

Patient and operative risk factors associated with permanent pacemaker placement. The blue square represents the estimated hazard ratio and the red lines extend from the lower limit to the upper limit of the estimated 95% confidence interval. Abbreviations: CI, confidence interval; HR, hazard ratio; MVS, mitral-valve surgery; NYHA, New York Heart Association; PPM, permanent pacemaker; PVI, pulmonary-vein isolation.

Figure 3.. PPM Placement and Readmission.

3A, Impact of PPM Placement, Age and Ablation on 30-Day Readmission. 3B, Impact of PPM Placement, Number of Previous Readmissions and Ablation on 1-Year Readmission. Abbreviations: CI, confidence interval; HR, hazard ratio; PPM, permanent pacemaker.