Impaired Left Atrial Contractile Strain and Late Pacemaker Implantation After the Cox–Maze Procedure Despite Maintained Sinus Rhythm

Late bradyarrhythmia requiring permanent pacemaker implantation remains a challenge after the Cox-Maze procedure. We evaluated whether left atrial contractile strain at 1 year predicts late pacemaker implantation in patients with normal sinus rhythm. We retrospectively analyzed 259 patients who underwent the Maze procedure between 2012 and 2024 and maintained normal sinus rhythm at 1 year. Left atrial contractile strain was assessed using two-dimensional speckle-tracking echocardiography. Of 329 patients screened, 50 were excluded for atrial fibrillation recurrence at 1 year (1-year freedom from atrial fibrillation, 83.8%). During follow-up (median 58 months), 22 patients required pacemaker implantation. The optimal strain cutoff was -1.8% (area under the curve 0.658), and patients with impaired left atrial function (strain ≥ -1.8%) had a higher incidence of pacemaker implantation (log-rank P < 0.001). Impaired left atrial contractile strain (hazard ratio 3.99; 95% confidence interval, 1.41-11.35), fine fibrillatory waves (3.64; 1.32-10.01), and increased preoperative left atrial volume (1.004 per mL; 1.001-1.008) were independent predictors, and a combined model improved predictive accuracy (area under the curve 0.782). The excess risk was concentrated within the first 5 years after surgery (hazard ratio 8.47 versus 2.22 thereafter). Impaired left atrial contractile strain 1 year after the Cox-Maze procedure independently predicts late pacemaker implantation despite stable normal sinus rhythm, particularly within the first 5 years, highlighting a dissociation between electrical and functional recovery. It may serve as a surrogate for atrial fibrosis and latent conduction disturbance, warranting intensified surveillance in high-risk patients during this period.