Prognostic Value of Global Longitudinal Strain-Based Left Ventricular Contractile Reserve in Candidates for Percutaneous Correction of Functional Mitral Regurgitation: Implications for Patient Selection

Abstract

Patients with symptomatic heart failure (HF), reduced left ventricular ejection fraction (LVEF), and high-grade functional mitral regurgitation (MR) may benefit from percutaneous edge-to-edge mitral valve repair (PMVR). However, patient selection still remains a central issue. We sought to investigate the potential role of the global longitudinal strain- (GLS-) based left ventricular contractile reserve (LVCR) at dobutamine stress echocardiography (DSE) in this setting. Thirty-three stable HF patients (MR grade≥3+; median LVEF, 29%; median GLS, -8.3%) who were candidates for PMVR were prospectively enrolled. All patients underwent DSE to assess LVCR (LVEF increase≥5%; GLS increase≥2%; stroke volume [SV] increase≥20% of the measured SV value). After DSE, a positive LVCRLVEF was detected in 21 patients (64%), positive LVCRGLS in 12 patients (36%), and positive LVCRSV in 14 patients (42%). LVCRGLS was associated with better symptom relief, MR improvement, and LV reverse remodeling in a short-term follow-up. A significant improvement of GLS during DSE (hazard ratio [HR], 0.549; 95% CI, 0.395-0.765; P<.001), along with history of HF hospitalization (HR, 1.48; 95% CI, 1.119-1.967; P=.006) and beta-blocker therapy (HR, 0.146; 95% CI, 0.046-0.462; P=.001), were independently associated with risk of death/heart transplantation/HF-related hospitalizations. LVCR, assessed by speckle-tracking DSE, is associated with better results after PMVR in the setting of advanced HF. Improvement of longitudinal function emerged, beyond the ejection fraction, as an independent predictor of outcomes and could improve the selection of best candidates for the percutaneous correction of functional MR.