Influence of obesity on left ventricular adaptation, grading and outcome in aortic valve stenosis

Abstract

Background/Aim: Obesity is associated with hemodynamic changes characterized by volume overload adding to the progressive pressure overload induced by aortic valve stenosis (AS). This thesis investigated whether concomitant obesity in patients with AS independently impacts left ventricular (LV) adaptation, grading and outcome during progression of the valve stenosis. Methods: The project was a planned substudy of the Simvastin Ezetimibe in Aortic Stenosis study (SEAS), a prospective, double-blind, placebo-controlled trial of the effect of statin treatment over 4.3 years in 1873 patients with initially mild to moderate AS. Body mass index (BMI) 25.0-29.9 kg/m2 defined overweight and BMI > 30 kg/m2 defined obesity. Results: In the first study, increasing BMI was associated with higher LV mass and lower LV systolic function in AS patients, independent of age, AS severity and presence of hypertension. In the second study, progression rate of AS did not differ between BMI classes. However, increased BMI predicted higher total mortality and combined rate of hospitalization for heart failure and death from any cause independent of AS severity and other confounders. Study 3 demonstrated that indexing aortic valve area (AVA) for body surface area in obesity was associated with high prevalence of discordant grading (severe AS by aortic valve area index (AVAI), but non-severe AS by AVA). Conclusions: The thesis demonstrates that overweight and obesity significantly influence LV response, grading and outcome in AS patients independent of other known confounders.