Abstract 12459: Is Ejection Fraction <50% the Optimal Threshold for Referral for Valve Replacement in Patients With Severe Aortic Stenosis? Impact of Ejection Fraction on Post-Operative Outcome

Abstract

Introduction: In asymptomatic patients with severe aortic stenosis (SAS), left ventricular (LV) ejection fraction (EF) <50% is generally considered to be the threshold for referral for aortic valve replacement (AVR). Hypothesis: We investigated the importance of LVEF on long-term outcome after AVR in symptomatic and asymptomatic SAS patients and studied whether LVEF < 50% is the optimal threshold for referral for AVR. Methods and Results: We retrospectively identified 2017 patients with SAS (aortic valve area (AVA)<1cm2, mean aortic valve gradient ≥40 mm Hg, or indexed AVA <0.6 cm2/m2) who underwent surgical AVR from January 1995 to June 2009 at our institution. 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%)). The primary end-point was all-cause mortality. During follow-up of 5.3±4.4 years, 1056 (52%) died. Five-year mortality rate increased with decreasing LVEF (41% (n=106), LVEF<50%); 35% (n=98), LVEF 50-59%; 26% (n=192), LVEF 60-69%; 22% (n=90), LVEF≥70%, p<0.0001). Compared to patients with LVEF≥60%, patients with LVEF 50-59% had increased mortality (HR 1.58, p<0.001), with a similar risk increase in both symptomatic (HR=1.56, p<0.001) and asymptomatic patients (HR 1.58, p=0.006, Figure). In a Cox regression analysis corrected for standard risk factors, LV mass index, AVA, and stroke volume index, LVEF was predictive of all-cause mortality (HR=0.89 per 10%, p<0.001). When this multivariable analysis was repeated in the subset of 1333 patients with no history of coronary artery disease, LVEF was still associated with all-cause mortality (HR=0.90 per 10%, p=0.009). Conclusion: In patients with SAS undergoing AVR, patients with LVEF 50-59% have also increased mortality compared to patients with LVEF>60%, suggesting that a different LVEF threshold should be used when referring for AVR.