Longitudinal strain in patients with severe aortic regurgitation: superiority to ejection fraction for detection of myocardial dysfunction

Abstract

Abstract Objectives The aim of the study was to analyse LV systolic function and mechanical energetics in asymptomatic patients with severe aortic regurgitation (AR) to seek a new hemodynamic concept for timing for surgery. Background Current guidelines suggest surgery for patients with severe AR including clinical symptoms, subnormal LV ejection fraction (EF), or markedly abnormal left ventricular dimensions. However, the optimal measure to detect intrinsic myocardial systolic dysfunction in the presence of normal LVEF remains elusive. Methods Strain and echo-derived single beat pressure-volume analyses were performed in cohorts with severe AR without indication for surgery (ARNS; LVEDD <70mm, EF >50%, n=41), with indication for surgery (ARS; n=19) and in healthy, age-matched controls (C; n=20). Additionally, end-systolic elastance (Ees=LV contractility), stroke work (SW) and total energy (PVA) were calculated. Results Patients with ARNS demonstrated significant depression of LV contractility vs. C: Ees (1.5mmHg/ml ±0.7 vs. 2.25mmHg/ml ±0.7; p<0.001), despite comparable ejection fractions (EF: 0.56±0.05 vs. 0.60±0.07; p=0.10). Accordingly, global longitudinal strain (GLS) was decreased (−16.0±2.5% vs. −21.5±2%; p<0.001), end-diastolic volume markedly enlarged (236ml ±90 vs. 136ml ±30; p<0.001), as were PVA and SW indicating waste of energy. The correlation of GLS vs. Ees was good (r=−0.68; p<0.001). Results of ARS-patients were consistently worse. Conclusion Patients with severe AR and normal LVEF showed depressed LV contractility and waste of energy when assessed by Ees and GLS, both correlating well with each other. Hence, GLS may outperform LV dimensions for predicting timing for surgery and clinical outcomes in AR patients. Funding Acknowledgement Type of funding source: None