Long-term outcomes of mini-sternotomy versus conventional sternotomy for aortic valve replacement: a randomized controlled trial

OBJECTIVES Aortic valve replacement (AVR) for severe symptomatic aortic stenosis is one of the most common cardiac surgical procedures with excellent long-term outcomes. Multiple previous studies have compared short-term outcomes of AVR with mini-sternotomy versus AVR with conventional sternotomy. We have previously reported the results of the randomized MAVRIC trial, which aimed to evaluate early postoperative morbidity among patients undergoing mini-sternotomy and conventional sternotomy AVR. We now report the long-term all-cause mortality, reoperation, MACE outcomes and echocardiographic data from this trial.

METHODS The prospective, randomized, single-centre, single-blind MAVRIC (manubrium-limited mini-sternotomy versus conventional sternotomy for aortic valve replacement) trial compared manubrium-limited mini-sternotomy and conventional median sternotomy for the treatment of patients with severe aortic stenosis. The previously reported primary outcome was the proportion of patients receiving red cell transfusion postoperatively and within 7 days of the index procedure. Currently reported exploratory analyses of a combined long-term all-cause mortality and reoperation were compared between groups via the log-rank test. Sensitivity analyses reviewed individual components of the combined end point. The primary analysis and long-term exploratory analyses were based on an intention-to-treat principle.

RESULTS Between March 2014 and June 2016, 270 patients were enrolled and randomized in a 1:1 fashion to undergo mini-sternotomy AVR (n = 135) or conventional median sternotomy AVR (n = 135). At the median follow-up of 6.1 years, the composite outcome of all-cause mortality and reoperation occurred in 18.5% (25/135) of patients in the conventional sternotomy group and in 17% (23/135) of patients in the mini-sternotomy group. The incidence of chronic kidney disease, cerebrovascular accident and myocardial infarction was not significantly different between 2 groups. Follow-up echocardiographic data suggested no difference in peak and mean gradients or incidence of aortic regurgitation between 2 approaches.

CONCLUSIONS This exploratory long-term analysis demonstrated that, in patients with severe aortic stenosis undergoing isolated AVR, there was no significant difference between manubrium-limited mini-sternotomy and conventional sternotomy with respect to all-cause mortality, rate of reoperation, MACE events and echocardiographic data at the median of 6.1-year follow-up.