Moderate aortic stenosis: a new actor has come into stage

摘要

It is well established that patients with severe aortic stenosis (AS) have a poor prognosis once symptoms develop. European and American guidelines both recommend surgical (SAVR) or transcatheter (TAVR) aortic valve replacement in severe AS in the presence of symptoms or left ventricular systolic dysfunction, defined as a left ventricular ejection fraction (LVEF) <50% (1,2). However, controversy still exists regarding the optimal timing of intervention in asymptomatic patients with severe AS, as several studies have shown that even truly asymptomatic patients based on an exercise test can have an increased risk of adverse events. Significant advances in SAVR and TAVR made in recent years have paved the way for large randomized trials that are currently evaluating the potential benefits of an early intervention in asymptomatic patients with severe AS (AVATAR, EvolVeD, ESTIMATE, EARLY-TAVR). Pending the results of these trials, staging the AS based on the evaluation of cardiac structural and hemodynamic changes as a whole, integrating information from rest and exercise echocardiography, cardiac magnetic resonance imaging (CMR) and biomarkers profile, can provide additional clues to the better understanding of the severity of the disease (3-5). In recent years, several small studies have shown that mild and moderate AS was not a benign disease, as initially envisioned, being associated with an increased incidence of cardiovascular events (6). As an example, Delesalle et al. reported an increased mortality rate (47%±3%) at 6 years of follow-up in patients with moderate AS and preserved LVEF (7). Patients with moderate AS and LV dysfunction appeared to have an even worse prognosis, with a 61% risk of adverse events (death, aortic valve replacement and heart failure hospitalization) at 6 years (8). In the HAVEC registry, concerning a larger cohort of patients with moderate AS, Lancellotti et al. reported a 2-, 4-, and 8-year survival rate of 94%±1%, 89%±2%, and 78%±4%, respectively. Independent determinants of cardiovascular mortality were body surface area, dyslipidemia, peak aortic jet velocity, LVEF and aortic valve intervention. A peak aortic jet velocity >3.5 m/s and a LVEF <60% were the predicting cut-off points associated with a worse outcome (9).