Sick Sinus Syndrome After the Maze Procedure Performed Concomitantly With Mitral Valve Surgery

Abstract

Background To characterize the development of sick sinus syndrome ( SSS ) after the additive maze procedure ( MP ) during mitral valve surgery. Methods and Results Follow-up data (median, 3.6 years) of 750 patients with a prevalence of rheumatic cause of 57.6% were analyzed. SSS occurred in 35 patients with a time-dependent increase: the incidence rates at 1, 2, and 4 years after surgery were 2.9%, 3.7%, and 4.3%, respectively. The additive MP showed higher risks of SSS development (hazard ratio, 7.44; 95% confidence interval, 3.45-16.05; P<0.001) and pacemaker implantation (hazard ratio, 3.61; 95% confidence interval, 1.95-6.67; P<0.001). Patients who developed SSS showed higher 4-year rates of clinical events (death, stroke, and hospital admission) (67.5±8.5% versus 33.0±1.9%; P<0.001). After adjustment for age and preoperative peak systolic pulmonary artery pressure, the lesion extent (biatrial versus left atrial MP ), not the underlying cause (rheumatic versus nonrheumatic), was independently associated with SSS development (hazard ratio, 3.58; 95% confidence interval, 1.08-11.86; P=0.037). The adverse effect of the biatrial MP was confirmed in patients with trivial or mild preoperative tricuspid regurgitation showing higher SSS incidence (4.6±1.4% versus 1.0±0.7%; P=0.023), not in those with moderate-to-severe tricuspid regurgitation (6.8±1.7% versus 3.8±3.8%; P=0.337). Recurrence of atrial fibrillation was not associated with the lesion extent of the MP . Conclusions After the additive MP , the ongoing risk of SSS development should be acknowledged irrespective of the underlying cause. Considering additive risk of biatrial MP with similar atrial fibrillation recurrence rate, minimizing lesion extent is warranted.

Keywords: atrial fibrillation; maze procedure; mitral valve surgery; sick sinus syndrome.

Figure 1

Flow diagram of the study population and summary of surgical procedures. MVS indicates mitral valve surgery; PPM, permanent pacemaker; and SSS, sick sinus syndrome.

Figure 2

Impact of the additive maze procedure on the development of sick sinus syndrome (A) and atrioventricular block (B) and their temporal patterns.

Figure 3

Time‐to‐event curves for adverse clinical events. The composite clinical outcomes included death, stroke, and hospital admission. A, Patients who developed sick sinus syndrome (SSS) during follow‐up showed higher event rates during follow‐up. The overall mortality was not significantly different (B); however, patients with SSS development showed higher rates of stroke (C) and rehospitalization (D).

Figure 4

Time‐to‐event curves showing the impact of rheumatic pathological features on clinical outcomes. Patients with rheumatic mitral valve disease were not at a higher risk of sick sinus syndrome development (A), permanent pacemaker implantation (B), recurrent atrial fibrillation (AF; C), or composite clinical outcomes (death, stroke, and rehospitalization; D).

Figure 5

Impact of the lesion extent of the maze procedure (biatrial vs left atrial [LA]) on the long‐term outcomes stratified according to the presence of moderate‐to‐severe tricuspid regurgitation (TR). Overall, the biatrial maze procedure resulted in higher rates of sick sinus syndrome (SSS) development (A) and atrial fibrillation (AF) recurrence (B). C and D, In patients with mild or no TR, the biatrial maze procedure resulted in a higher rate of SSS development with a similar rate of recurrent AF. E and F, In patients with moderate‐to‐severe TR, there was no difference in the SSS development or recurrent AF according to the lesion extent of the maze procedure.