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OBJECTIVE: Low ejection fraction (EF<40%) portends adverse outcomes in patients undergoing valvular heart surgery. The role of traditional median sternotomy (SAVR) compared to minimally invasive (MIAVR) aortic valve replacement in this cohort remains incompletely understood.
METHODS: A multi-institutional retrospective review of 1,503 patients undergoing SAVR (n=815) and MIAVR via right anterior thoracotomy (n=688) from 2011-2014 was performed. Patients were stratified into two groups: EF < 40% and EF ≥ 40%. In each EF group, MIAVR and SAVR patients were propensity matched by age, gender, BMI, race, diabetes, hypertension, dyslipidemia, dialysis, cerebrovascular disease, cardiovascular disease, CVA, PVD, last creatinine level, EF, previous MI and cardiogenic shock, and STS score. Continuous variables were compared using paired t-test and categorical variables were compared using the McNemar Test.
RESULTS: Among patients with an EF≥40% (377 pairs), patients undergoing MIAVR compared to SAVR had decreased ICU hours (56.8 vs. 84.6, p<0.001), postoperative length of stay (7.1 vs. 7.9 days, p=0.04), bleeding (0.8% vs. 3.2%, p=0.04), and a trend towards decreased 30-day mortality (0.3% vs. 1.3%, p=0.22). STS scores were largely equivalent in patients undergoing MIAVR compared to SAVR (2.4 vs. 2.6, p=0.09). In patients with an EF<40% (35 pairs), there was no difference in ICU hours (69 vs. 72.6, p=0.80), postoperative length of stay (10.3 vs. 7.2, p=0.13), 30-day mortality (3.8% vs. 0.8%), or STS score (3.3 vs. 3.2, p=0.68).
CONCLUSIONS: MIAVR in patients with preserved EF was associated with improved short outcomes compared to SAVR. In patients with left ventricular dysfunction, short-term outcomes between MIAVR and SAVR are largely equivocal.