Effect of left ventricular ejection fraction on postoperative outcome in patients with severe aortic stenosis undergoing aortic valve replacement.

BACKGROUND

In asymptomatic patients with severe aortic stenosis, guidelines recommend left ventricular ejection fraction (LVEF) of <50% as the threshold for referral for aortic valve replacement. We investigated the importance of LVEF on long-term outcome after aortic valve replacement in symptomatic and asymptomatic patients with severe aortic stenosis.

METHODS AND RESULTS

We retrospectively identified 2017 patients with severe aortic stenosis (aortic valve area<1 cm(2), mean gradient≥40 mm Hg, or indexed aortic valve area<0.6 cm(2)/m(2)) who underwent surgical aortic valve replacement from January 1995 to June 2009. Patients were divided into 4 groups depending on preoperative LVEF (<50% in 300 [15%] patients, 50%-59% in 331 [17%], 60%-69% in 908 [45%], and ≥70% in 478 [24%]). During follow-up of 5.3±4.4 years, 1056 (52%) patients died. A decrease in mortality was observed with increasing LVEF, P<0.0001; 5-year mortality estimates (95% confidence interval) were 0.41 (0.35-0.47), LVEF<50%; 0.35 (0.29-0.41), LVEF 50% to 59%; 0.26 (0.23-0.29), LVEF 60% to 69%; and 0.22 (0.18-0.26), LVEF≥70%. Compared with patients with LVEF≥60%, patients with LVEF 50% to 59% had increased mortality (hazard ratio [HR], 1.58; P<0.001), with similar risk increase in both symptomatic (HR, 1.56; P<0.001) and asymptomatic patients (HR, 1.58; P=0.006). Correcting for risk factors, LV mass index, aortic valve area, and stroke volume index, LVEF was independently predictive of mortality (HR, 0.88 per 10%; P<0.001). When this analysis was repeated in the subset of 1333 patients without history of coronary artery disease, LVEF remained associated with mortality (HR, 0.90 per 10%; P=0.009).

CONCLUSIONS

LVEF is a powerful predictor of outcome in patients with severe aortic stenosis undergoing aortic valve replacement, independent of the presence of valve-related symptoms.