Minimally invasive approach compared to resternotomy for mitral valve surgery in patients with prior cardiac surgery: retrospective multicentre study based on the Netherlands Heart Registration

Objectives: Mitral valve (MV) surgery after prior cardiac surgery is conventionally performed through resternotomy and associated with increased morbidity and mortality. Alternatively, MV can be approached minimally invasively [minimally invasive mitral valve surgery (MIMVS)], but longer-term follow-up of this approach for MV surgery after prior cardiac surgery is lacking. Therefore, the aim of the current study is to evaluate short- and mid-term outcomes of MIMVS versus MV surgery through resternotomy in patients with prior sternotomy, using a nationwide registry.

Methods: Patients undergoing isolated MV surgery after prior cardiac surgery between 2013 and 2018 were included. Primary outcomes were short-term morbidity and mortality and mid-term survival. Cox proportional hazard analysis was used to investigate the association between surgical approach and mortality. Propensity score matching was used to correct for potential confounders.

Results: In total, 290 patients underwent MV surgery after prior cardiac surgery, of whom 205 patients were operated through resternotomy and 85 patients through MIMVS. No significant differences in 30-day mortality (3.4% vs 2%, P = 0.99) were observed between both groups. Five-year survival was 86.3% in the resternotomy group, compared to 89.4% in the MIMVS group (log-rank P = 0.45). In the multivariable analysis, surgical approach showed no relation with mid-term mortality [hazard ratio 0.73 (0.34-1.60); P = 0.44]. A lower incidence of prolonged intubation and new-onset arrhythmia was observed in MIMVS.

Conclusions: MV surgery after prior cardiac surgery has excellent short- and mid-term results in the Netherlands, and MIMVS and resternotomy appear to be equally efficacious. MIMVS is associated with a lower incidence of new-onset arrhythmia and prolonged intubation.