Patterns of left ventricular remodeling in aortic stenosis: therapeutic implications

Abstract

Aortic valve stenosis is characterized by indolent progression followed by the late development of symptoms once left ventricular compensatory mechanisms fail. In this review, we describe the left ventricular response to aortic stenosis. Specifically, we highlight the process of adaptive remodeling, which begins as a beneficial compensatory mechanism but ultimately transitions to a maladaptive process characterized by inappropriate left ventricular hypertrophy, interstitial fibrosis, and diminished contractility. Myocardial fibrosis ensues as the remodeling process progresses with potentially irreversible consequences on diastolic and systolic function and on clinical symptoms and outcomes. Recent data suggest that fibrosis is largely responsible for the development of symptoms in patients with severe aortic stenosis, which unfortunately implies that fibrosis may be advanced by the time clinical symptomatology triggers evaluation for aortic valve replacement. Interstitial fibrosis persists for years after valve replacement and, when severe, can lessen the clinical benefits of valve replacement. Further evaluation of noninvasive measures capable of assessing the extent of maladaptive left ventricular remodeling and of predicting its reversal are desperately needed in order to enhance the personalized delivery of aortic valve replacement for severe aortic stenosis. We support aggressive assessment of symptomatic status with more frequent clinical follow-up and exercise testing in asymptomatic individuals with severe left ventricular hypertrophy or impaired longitudinal contractility. However, whether early valve replacement is advantageous in patients with evidence of maladaptive left ventricular remodeling in the absence of symptoms remains unknown, but is certainly worthy of further investigation.