Left ventricular systolic performance in asymptomatic aortic stenosis
Department of Medicine B2142, The Heart Center, Rigshospitalet, 9 Blegdamsvej DK-2100, Copenhagen, Denmark
* Corresponding author. Tel: +45 3545 0888; fax: +45 3545 2513. E-mail address: kristian{at}wachtell.net
Some asymptomatic patients with aortic stenosis (AS) are at higher risk of impending symptom onset or adverse clinical outcome than others. This article explores whether parameters of left ventricular (LV) systolic performance may identify asymptomatic patients with AS who are most likely to benefit from aggressive treatment interventions. Studies evaluating the influence of LV systolic function on outcomes in asymptomatic patients with AS were reviewed. Several factors are associated with poor outcomes in AS, including low chamber function (assessed by LV ejection fraction; LVEF) and depressed myocardial contractility (assessed by low midwall fractional shortening; MFS). In most patients, LV wall stress is inversely correlated with LVEF; LV hypertrophy and LV systolic dysfunction develop from the high wall-stress and afterload mismatch. Depressed myocardial contractility may as well identify patients with poor prognoses before clinical symptoms. High global afterload (reflected by a valvulo-arterial impedance Zva 
5.5 mmHg/mL/m2) seen in patients with paradoxically low-flow/low-gradient AS can identify patients at high risk of adverse outcomes, and finally high LV stroke work loss (25%) can also identify patients at risk. Parameters of LV systolic performance can identify patients with asymptomatic AS who are at high risk of impending symptoms of heart failure and adverse clinical outcomes. Such patients may benefit from more aggressive treatment interventions, including aortic valve replacement.
Key Words: Aortic stenosis • Left ventricular wall stress • Midwall fractional shortening • Global afterload • Left ventricular stroke work loss