Does Body Mass Index Impact Outcomes in Patients Undergoing Minimally Invasive Mitral Valve Surgery?

Background and Objectives: This study examines the impact of Body Mass Index (BMI) on outcomes after mitral valve surgery via right minithoracotomy, an approach that may reduce wound complications in obese patients. Materials and Methods: Between January 2010 and December 2024, 1773 adult patients underwent minimally invasive mitral valve surgery at our institution. They were categorized into three groups: normal weight (BMI < 25, n = 942), overweight (BMI 25-30, n = 661), and obese (BMI > 30, n = 170). Results: The three groups exhibited significant differences, with a higher prevalence of hypertension, dyslipidemia, and diabetes (p < 0.001) in overweight and obese patients. Further-more, they had a greater incidence of preoperative atrial fibrillation (p < 0.001), prior stroke (p = 0.023), chronic obstructive pulmonary disease (p = 0.002), and elevated preoperative creatinine levels (p < 0.001). and their euroscore II was significantly higher (p = 0.040). In-hospital mortality and major complications were similar across groups, except for drainage output in the first 24 h (p = 0.002) and ICU stay (p = 0.022), both resulting higher in the overweight and obese patients. We employed inverse probability of treatment weighting (IPTW) to create three well-matched groups. Following IPTW, postoperative outcomes remained comparable across groups. However, obese patients exhibited a higher incidence of postoperative atrial fibrillation (p = 0.037) and required pacemaker implantation more frequently (p < 0.001). Conclusions: Our findings suggest that obesity does not increase the risk of mortality or major adverse events after minimally in-vasive mitral valve surgery. This approach may offer a less invasive alternative for obese patients, potentially reducing the risk of wound complications associated with conventional surgery.