Abstract 15062: Incremental Prognostic Utility of LV Global Longitudinal Strain and Functional Capacity in Asymptomatic Patients With Significant Primary Mitral Regurgitation and Preserved Left Ventricular Ejection Fraction Undergoing Rest-Stress Echocardiography

Abstract

Background: Outcomes after mitral valve (MV) surgery for primary mitral regurgitation (PMR) are excellent; however surgical timing in asymptomatic PMR & preserved left ventricular ejection fraction (LVEF) remains challenging. We assessed the incremental utility of resting LV-global longitudinal strain (LV-GLS) & exercise variables in asymptomatic patients with ≥3+ PMR & preserved LVEF (≥60%) who underwent rest-stress echocardiography. Methods: We included 737 such patients (58±13 years, 68% men) between 2000-11. Clinical, resting (including LV-GLS using Velocity Vector Imaging & right ventricular systolic pressure or RVSP) & exercise stress echo (metabolic equivalents or METs) data were recorded. Society of Thoracic Surgeons (STS) score was calculated. Primary events were death & heart failure admission. Results: Hypertension, atrial fibrillation (AF) and coronary artery disease were seen in 48%, 13% & 10% patients. Posterior, anterior & bileaflet prolapse were noted in 46%, 9% & 45% (20% had flail). Mean STS score, resting LVEF, resting RVSP, exercise MET’s & % age-gender predicted MET’s were 1.5±1, 62±2%, 31±12 mmHg, 9.8±3 & 115±27 respectively. 65% underwent MV surgery with mean time to surgery 13±22 months. At 6.2±3 years, events occurred in 61 (8%) patients (death in 33 patients). On multivariable Cox survival analysis, higher rest RVSP (Hazard ratio or HR 1.04), lower % age-gender predicted METS (HR 1.11), lower LV-GLS (HR 1.42), higher STS score (HR 1.12) & AF (HR 2.23) were significantly associated with events (all p<0.05). Association of MV surgery (time-dependent covariate) with outcomes was not significant (HR 0.63 [0.38-1.07, p=0.1). Figure 1a shows an incremental model with association to outcomes & 1b shows survival curves, based on LV-GLS better/worse than median (-21.7%). Conclusions: In asymptomatic patients with ≥3+ PMR & preserved LVEF, lower baseline LV-GLS & %age-gender predicted METs are associated with long-term adverse events.