Prognostic contribution of left ventricular myocardial work assessment in mitral valve prolapse

Abstract

Mitral Valve Prolapse (MVP) is the leading cause of primary mitral regurgitation (MR). Due to volume overload-induced changes in severe MR, assessment of left ventricular systolic function, an important marker to refer patients to surgery, is difficult. The aim of our study was to assess cardiac mechanics based on the non-invasive evaluation of myocardial work, by analysing the left ventricular pressure-strain loop, taking into account loading conditions. In total, 321 patients (63% male) with MVP (with or without severe MR), who underwent a comprehensive echocardiography and cardiac magnetic resonance (CMR) between 2010 and 2021, were included. Myocardial work parameters were assessed using a dedicated software. The primary endpoint associated cardiovascular death, sustained ventricular arrhythmia, heart failure, new onset atrial fibrillation, or arterial embolism. Of the 321 patients 186 (58%) had a GWW (global wasted work) < 120 mmHg% and 135 (42%) a GWW ≥ 120 mmHg%. GWW < 120 mmHg% was associated with echographic and CMR parameters of abnormal filling, volume overload and more severe regurgitation. During a mean follow-up of 4.5 ± 2.8 years, censored at the time of mitral valve surgery, 36 cardiovascular events were recorded in the GWW < 120 mmHg% group versus 14 in the GWW ≥ 120 mmHg% group (19% vs. 10%; P = 0.028). Heart failure (15 vs. 6%; P = 0.011) and mitral valve intervention (69 vs. 59%; P = 0.045) rates were higher in the GWW < 120 mmHg% group. Five-year cardiovascular event-free survival was decreased in patients with GWW < 120 mmHg% (46.6 ± 7.7% vs. 59.1 ± 12.4%; P = 0.023). In multivariable analysis, MR severity, the presence of late enhancement on CMR, and GWW < 120 mmHg% (HR 1.76; 95% CI 0.93–3.34; P = 0.085) were associated with impaired event-free survival. Myocardial work-up provides additional diagnostic and prognostic information to echocardiography and cardiac MRI in MV.