Minimally invasive versus sternotomy mitral valve surgery when initiating a minimally invasive programme

An increasing number of mitral valve operations are performed using minimally invasive procedures. The initiation of a minimally invasive mitral valve surgery programme constitutes a unique opportunity to study outcome differences in patients with similar characteristics operated on through a sternotomy versus a minimally invasive procedure. The goal of this study was to compare short-term outcomes of patients undergoing mitral valve surgery before versus those having surgery after the introduction of a minimally invasive programme.

The single-centre study included mitral valve procedures performed through a sternotomy or with a minimally invasive approach between January 2012 and May 2019. Propensity score matching was performed to reduce selection bias.

A total of 605 patients (294 sternotomy, 311 minimally invasive) who underwent mitral valve surgery were included in the analysis. Propensity score matching resulted in 251 matched pairs. In the propensity score-matched analysis, minimally invasive procedures had longer extracorporeal circulation duration (149 ± 52 vs 133 ± 57 min; P = 0.001) but shorter aortic occlusion duration (97 ± 36 vs 105 ± 40 min, P = 0.03). Minimally invasive procedures were associated with a lower incidence of reoperation for bleeding (2.4% vs 7.2%; P = 0.012), lower need for transfusion (19.1% vs 30.7%; P = 0.003) and shorter in-hospital stay (5.0 ± 2.7 vs 7.2 ± 4.6 days; P < 0.001). The 30-day mortality was low in both groups (0.4% vs 0.8%; P = 0.56).

Minimally invasive mitral valve surgery was associated with short-term outcomes comparable to those with procedures performed through a sternotomy. Initiating a minimally invasive mitral valve programme with a limited number of surgeons and a well-executed institutional selection strategy did not confer an increased risk for adverse events.