Stress Echocardiography and Strain in Aortic Regurgitation (SESAR protocol): Left ventricular contractile reserve and myocardial work in asymptomatic patients with severe aortic regurgitation

Objectives: To analyze left ventricular (LV) myocardial deformation and contractile reserve (CR) in asymptomatic patients with severe aortic regurgitation (AR) at rest and during exercise, and their correlation with functional capacity. Background: The natural history of chronic AR is characterized by a prolonged silent phase before onset of symptoms and overt LV dysfunction. Assessment of LV systolic function and contractile reserve has an important role in the decision-making of AR asymptomatic patients. Methods: Standard echo, lung ultrasound, and LV 2D speckle tracking strain were performed at rest and during exercise in asymptomatic patients with severe AR and in age- and sex-comparable healthy controls. Results: 115 AR patients (male sex 58.2%; 52.3 ± 18.3 years) and 55 controls were enrolled. Baseline LV ejection fraction was comparable between the groups. Resting LV global longitudinal strain (GLS) and myocardial work efficiency (MWE) were significantly reduced in AR (GLS-15.8 ± 2.8 vs −21.4 ± 4.4; P <.001). Patients with AR and CR− showed reduced resting LV GLS and MWE and increased B-lines. MWE was closely related to peak effort watts, VO2, LV E/e′, and B-lines, at a multivariable analysis. Both GLS and MWE were strong independent predictors of CR. A resting LV GLS cutoff of −12% differentiated CR+ and CR− (78% sensitivity and 84% specificity). Conclusions: The lower resting values of LV GLS and MWE in severe AR asymptomatic patients suggest an early subclinical myocardial damage that seems to be closely associated with lower exercise capacity, greater pulmonary congestion, and blunted LV contractile reserve during stress.