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.

Coronary Microcirculation in Aortic Stenosis

“…82,86–88,92,94–106 Some discrepant studies (which include a high proportion of asymptomatic patients or fail to account for stroke volume) 107–110 have been criticized for imprecise data analysis and misclassification. 111 The phenomenon of distinct remodeling is poorly understood, and there is a paucity of invasive data to characterize the cohort and understand factors that predict poor outcome and the response to valve intervention.…”

New classification of geometric ventricular patterns in severe aortic stenosis: Could it be clinically useful?

“…Aortic valve stenosis (AS) is characterized by an active, progressive process of thickening of valve leaflets and formation of calcium nodules which results in a narrow valve orifice and leads to an important obstruction of blood flow across the valve. Initially, the left ventricle (LV) response to increased afterload consists of an adaptive compensatory mechanism with gradual wall thickening to maintain normal wall stress and systolic function . During disease progression, LV hypertrophy (LVH) is followed by interstitial fibrosis starting at the subendocardial layers .…”

The role of the left atrial function in the surgical management of aortic and mitral valve disease

“…Aortic stenosis (AS) is the most common primary valve disease leading to surgery or catheter intervention in the West, and therefore its social relevance is particularly high. AS determines an increased LV pressure overload, which causes LV hypertrophy, myocardial fibrosis, and impaired relaxation . According to current guidelines, valve replacement is recommended when the patient is symptomatic or when left ventricular ejection fraction (LVEF) is <50% .…”

“…AS determines an increased LV pressure overload, which causes LV hypertrophy, myocardial fibrosis, and impaired relaxation. 8 According to current guidelines, valve replacement is recommended when the patient is symptomatic or when left ventricular ejection fraction (LVEF) is <50%. 1,3 However, the prevalence of AS is high in the elderly and, in this subset of patients, symptoms might be underrecognized since their physical activity is reduced, 9 which might lead to a late replacement with worse outcome in the long term.…”