Long-Term Outcomes After Valve Replacement for Low-Gradient Aortic Stenosis

Background— The long-term outcomes of patients with low-gradient aortic stenosis (LGAS) after aortic valve replacement (AVR) are poorly defined. The purpose of this study was to define the long-term outcomes of LGAS patients after AVR and to evaluate the potential impact of prosthesis–patient mismatch (PPM) in these patients.Methods and Results— A cohort of 664 patients undergoing AVR for aortic stenosis after 1990 were followed-up prospectively with annual clinical assessment and echocardiography (total follow-up 3447 patient-years; mean follow-up 5.2±3.3 years). LGAS was defined as an aortic valve area <1.2 cm2 , a mean transvalvular pressure gradient <40 mm Hg, and a left ventricular (LV) ejection fraction <50%, and was present in 79 patients. Rates and correlates of survival, freedom from congestive heart failure (CHF), and LV mass regression after AVR were determined using multivariate regression methods. Ten-year survival and freedom from CHF after AVR were 72.7±7.5% and 68.2±9.5%, respectively, for patients with LGAS, compared with 89.6±1.8% and 84.1±4.2% for patients without LGAS (hazard ratio [HR] for death and postoperative CHF, 3.1±1.1 and 2.7±0.9, respectively;P <0.01). In LGAS patients, PPM, defined as an indexed effective orifice area ≤0.85 cm2 /m2 , was independently associated with increased rates of CHF (HR, 3.6±2.2;P =0.039), impaired LV mass regression (P =0.037), and a trend toward increased late mortality (HR, 3.0±1.9;P =0.084).Conclusions— Patients with LGAS have worse long-term outcomes after AVR compared with patients without LGAS. PPM adversely affects the long-term outcomes of LGAS patients and should be avoided in this population.