Mitral Valve Repair in Patients With Class I Obesity: A Propensity-Matched Analysis

Obesity may increase the technical complexity of robotic mitral valve (MV) repair, but comparative outcomes with sternotomy remain poorly defined.

This study aimed to compare perioperative and long-term outcomes of robotic vs sternotomy MV repair in patients with class I obesity.

A total of 880 patients with class I obesity (body mass index 30-34.9 kg/m²) underwent MV repair at our clinic between 2008 and 2025. After excluding those with mitral stenosis, active endocarditis, prior sternotomy, or concomitant procedures, 429 patients remained. Propensity score matching (1:1) yielded 132 patients in each group who underwent either robotic or conventional sternotomy MV repair.

Median age was 59 years (IQR: 52-66), and 81% were male. Cardiopulmonary bypass and cross-clamp times were longer in the robotic group than in the sternotomy group (86 vs 65 minutes and 60 vs 48 minutes, respectively; P < 0.001). Robotic MV repair was associated with shorter hospitalization (3.5 vs 5 days; P < 0.001) and a lower postoperative transfusion rate (1.5% vs 10.6%; P = 0.002). There were no operative deaths in either group. No sternal wound infections occurred. Thirty-day readmission was numerically higher after robotic repair (12.8% vs 4.3%; P = 0.064). Ten-year survival was 92% (95% CI: 87% to 97%) with no significant difference between groups (P = 0.83).

In patients with class I obesity, the robotic approach in comparison to sternotomy was associated with lower transfusion rates, shorter hospitalization, and comparable operative mortality and long-term survival relative to sternotomy. Although 30-day readmission was numerically higher among robotic patients, most events were minor and managed without intervention.