Background: The optimal timing of aortic valve replacement (AVR) among patients with asymptomatic severe aortic stenosis (AS) remains uncertain and controversial.
Methods: We conducted a cohort study of consecutive patients with severe AS (mean gradient, 40 mm Hg; aortic valve area <1 cm², or peak velocity ≥4 m/s) who were asymptomatic at the time of echocardiography (2005-2015). Outcomes included mortality, AVR, or AS symptoms. Kaplan-Meier curves and the log-rank test were used to compare the outcomes of patients treated with AVR compared with conservative management. Cox proportional-hazards regression analysis was performed to identify predictors of long-term mortality.
Results: Of 1181 echocardiograms and medical records reviewed, a total of 324 patients met inclusion criteria. The mean age of the study cohort was 78 ± 10 years and 97% were male. The median follow-up time was 8 years (interquartile range [IQR], 7-10 years), during which 147 patients (51%) underwent AVR and 94 patients (29%) died. The median survival for patients treated with AVR was 10 years (IQR, 9-10 years) and for patients managed conservatively was 4.8 years (IQR, 3.7-5.7 years; P<.001). A total of 47 patients (14% of the cohort and 48% of deaths) expired before AS symptoms were documented in their medical records. Independent predictors of mortality were age (hazard ratio [HR] per increase in decile, 1.14; 95% CI, 1.05-1.24; P<.01) and performance of AVR during follow-up (HR, 0.15; 95% CI, 0.9-0.28; P<.01).
Conclusion: A significant proportion of elderly patients with initially asymptomatic severe AS died before symptoms were identified. Our study highlights the difficulty of relying on symptoms alone for timely referral to AVR surgery.
Keywords: aortic stenosis; natural history; prognosis.