Abstract 21150: Surgical Treatment of Asymptomatic Severe Aortic Stenosis: Impact of Surgical Timing on Long-Term Survival

Abstract

Introduction: Aortic valve (AV) replacement (AVR) is regarded as the only effective treatment for severe aortic stenosis (AS). The current guidelines, however, agree with watchful waiting in asymptomatic AS patients with normal left ventricular (LV) function. Hypothesis: This study aims to assess the hypothesis that timely surgical intervention is associated with the improved long-term survival in asymptomatic severe AS patients. Methods: Between 2000 and 2015 in our institution, we identified 505 patients (aged 63.9±13.1 years, 252 females) having asymptomatic severe AS (aortic valve area [AVA] ≤ 1.0cm 2 , peak trans-AV velocity [V max ] ≥ 4.0m/s or mean AV pressure gradient [PG] ≥ 40mmHg) with preserved LV function (ejection fraction ≥ 50%). Among them, very severe AS (AVA ≤ 0.6cm 2 , V max ≥ 5.0m/s or mean PG ≥ 60mmHg) was found in 152 (29.9%) patients. AVR was performed in 231 (45.7%) patients within 3 months after diagnosis (n=145) or during follow-up (n=86) thereafter either by surgical AVR (n=214) or by trans-catheter AVR (n=17). Time-varying Cox-proportional hazard models were used to determine the impact of surgical therapy on survival outcomes. Results: During a median follow-up of 58.3 months (Q1-Q3, 29.6-104.6 months), 163 (32.3%) patients died. On time-varying Cox-hazard models, surgical therapy was associated with a significant risk reduction in overall death (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.43-0.94; P=0.022) after adjusting with 32 significant risk factors for mortality. Survival benefits by AVR were consistently demonstrated in most risk subgroups of patients based on ages, severity of AS and the morphology of the AV (bicuspid) (Figure). Conclusions: Timely AVR in asymptomatic severe AS patients resulted in marked survival benefits. These study results may suggest that early robust recruitment for surgical therapy may be warranted in asymptomatic severe AS patients before developing ventricular deterioration or onset of symptoms.