Metabolic Determinants of the Progression of Aortic Stenosis

Calcific aortic stenosis (AS) has become the most common cardiac disease after coronary artery disease and hypertension. Unfortunately no medical therapies have been proven to decrease either the progression of valve stenosis or the resulting adverse effects on myocardial remodeling and function. In light of the studies performed in PROGRESSA, it becomes obvious that: i) AS is a complex and actively regulated process that involves the interaction of several pathways including lipid infiltration and retention, chronic inflammation, osteogenic activation, and active mineralization within the valvular tissues; ii) AS is not a disease strictly limited to the aortic valve but rather a systemic disease that often involves calcification and stiffening of the aorta and impairment of LV function as a consequence of pressure overload. Our findings suggest that the dysmetabolic milieu linked to visceral obesity may accelerate the deterioration of the structure and function not only of the aortic valve but also of the aorta and of the left ventricle. These findings open new avenues of research and provide strong impetus for the elaboration of prospective studies focusing on the "valvulo-metabolic risk" in AS. The general hypotheses are: The metabolic abnormalities linked to visceral obesity accelerate (1) the progression of valvular calcification and stenosis, aortic calcification and stiffness; (2) the progression of myocardial fibrosis and dysfunction. The general objectives of the study are to elucidate the mechanisms implicated in the pathogenesis of AS and to identify the metabolic factors that determine the progression of: i) aortic valve calcification and stenosis; ii) myocardial fibrosis and dysfunction; and iii) clinical outcomes. This study will contribute to identifying the key metabolic determinants of AS progression and will pave the way for the future development of non surgical therapies for this disease. The results of this study would provide strong support to the realization of randomized trial to test the efficacy of lifestyle modification program or new pharmacological treatment aiming at the reduction of visceral fat and associated metabolic abnormalities in the AS population. Furthermore, this study will contribute to the identification of novel blood and imaging biomarkers of faster disease progression, which will help to optimize risk stratification and timing of AVR in the AS population.