Mitral valve surgery and maze procedure: the Korean experience in rheumatic versus degenerative disease

In Korea, rheumatic mitral valve (MV) disease remains relatively prevalent compared with Western countries. Given this demographic profile, we aimed to evaluate long-term rhythm and clinical outcomes of surgical ablation of atrial fibrillation (AF) during MV surgery in patients with degenerative versus rheumatic MV disease, using the data from the nation's highest-volume center.

We retrospectively analyzed consecutive patients with AF who underwent MV surgery with concomitant surgical ablation between 2001 and 2020 at a high-volume center in Korea. Patients were categorized by MV etiology (rheumatic vs. degenerative). The primary outcome was AF recurrence after a 3-month blanking period. Secondary outcomes included all-cause mortality, stroke, and permanent pacemaker (PPM) implantation. The probability of AF recurrence was estimated using logistic regression with generalized estimating equations, and competing risk models were used to assess stroke and PPM implantation.

Among 1,872 patients (mean age 58.7±11.5 years; 56.9% women), 1,157 (61.8%) had rheumatic MV disease, and 715 (38.2%) had degenerative disease. Compared with patients with degenerative disease, those with rheumatic disease were younger, more often female, had more persistent AF, larger left atrial dimensions, and a higher likelihood of undergoing MV replacement. The adjusted probability of AF recurrence at 3, 5, and 10 years was 23.6%, 28.6%, and 40.1%, respectively, and did not significantly differ between rheumatic and degenerative groups (10-year: 39.8% vs. 40.6%; P=0.746). Rheumatic etiology was not associated with an increased risk of death (P=0.518), stroke (P=0.520), or PPM implantation (P=0.052).

In a contemporary Korean cohort, surgical ablation during MV surgery provided sustained rhythm control and favorable clinical outcomes in patients with both degenerative and rheumatic disease. Given the continued burden of rheumatic heart disease in Korea, these findings support the routine application of surgical ablation during MV surgery, regardless of underlying etiology.