Aortic valve stenosis in community medical practice: determinants of outcome and implications for aortic valve replacement

Abstract

Objective: To define the objective and subjective measures of aortic stenosis (AS) severity linked to survival after diagnosis in community practice.

Methods: All 360 Olmsted County, Minnesota residents (74 ± 14 years; 44% men) with AS diagnosed from 1988 to 1997 by echocardiography and without life-threatening comorbid conditions were enrolled. The presentation at first diagnosis, outcomes (mortality, heart failure, cardiac surgery), and coherence of guideline-based criteria for severe AS were analyzed.

Results: The presentation was challenging. Cardiac symptoms were frequent (59%) and unassociated with the AS severity (all P > .13). Of the patients with severe AS, as determined by a valve area less than 1.0 cm(2), 67% had low gradient AS (≤40 mm Hg). An aortic valve area less than 1.0 cm(2) was the only objective measure independently determining survival (adjusted risk ratio, 1.81; 95% confidence interval [CI], 1.19-2.70; P < .01) and heart failure (adjusted risk ratio, 2.3; 95% CI, 1.3-4.0; P < .01), even in patients with low-gradient AS and/or an ejection fraction of 50% or greater. Excess mortality (vs expected mortality) occurred with an aortic valve area of less than 1.0 cm(2) (risk ratio, 1.78; 95% CI, 1.33-2.35; P < .001) even without symptoms (risk ratio, 1.65; 95% CI, 1.05-2.47; P = .02). Aortic valve replacement, ultimately performed in only 45% of those with an aortic valve area less than 1.0 cm(2), reduced mortality (risk ratio, 0.61; 95% CI, 0.39-0.94; P = .02) and heart failure (risk ratio, 0.29; 95% CI, 0.13-0.64; P < .01).

Conclusions: In community practice, AS affects elderly patients, and its presentation is challenging owing to the high frequency of low-gradient severe AS despite a normal ejection fraction and because symptoms are frequently not specific to AS. Consequently, aortic valve replacement is seldom performed despite its considerable benefit. Physicians should be aware that an aortic valve area of less than 1.0 cm(2) predicts for unfavorable outcomes, irrespective of symptoms or gradient. Thus, such patients should undergo a thorough evaluation to detect those who could benefit from aortic valve replacement, despite their challenging presentation.