Assessment of Subclinical Left Ventricular Dysfunction in Aortic Stenosis

Left ventricular (LV) systolic dysfunction is an adverse consequence of the pressure overload of severe aortic stenosis (AS). The enlargement of the interstitial space with reactive fibrosis and subsequently with replacement fibrosis and cell death has been suggested to be the main driver of the transition to symptoms, heart failure, and adverse cardiovascular events even after aortic valve replacement (AVR). Early and accurate recognition of myocardial dysfunction offers the potential to optimize the timing of intervention in severe AS. In the asymptomatic patient, an LV ejection fraction (EF) cutpoint of <50% has been used for this purpose. However, in most asymptomatic patients, an LVEF <50% is uncommon, and patients with an LVEF of 50% to 59% fare almost as badly. Moreover, the presence of a small LV cavity, the reliability and automation of the global longitudinal strain (GLS) signal, and the independent prognostic role of GLS are reasons why GLS could be expected to be a better marker of subclinical LV dysfunction in these patients. This review seeks to define whether the existing EF cutoff in AS should be modified or whether GLS should replace it as the marker of subclinical LV dysfunction.