Abstract 14693: Incremental Utility of BNP and LV Global Longitudinal Strain in Predicting Post-operative LV Systolic Dysfunction and Outcomes in Asymptomatic Patients With Significant Primary Mitral Regurgitation Undergoing Mitral Valve Surgery

Abstract

Background: Outcomes after mitral valve (MV) surgery for primary mitral regurgitation (PMR) are excellent. However, some patients have a drop in post-op left ventricular ejection fraction (LVEF), despite preserved pre-op LVEF. In asymptomatic patients with ≥3+ PMR with preserved pre-op LVEF (≥60%) who underwent MV surgery for class IIa indications, we assessed the incremental ability of brain natriuretic peptide (BNP) & LV-global longitudinal strain (LV-GLS) to predict a) a reduction in post-op LVEF & b) long-term mortality. Methods: We included 448 such patients (61±12 years, 69% men) who had MV surgery between 2005-08. Clinical (including logBNP), baseline (including LV-GLS using Velocity Vector Imaging) & follow up echo (LVEF) data were recorded. Post-op LVEF <50% was considered abnormal. Society of Thoracic Surgeons (STS) score was calculated. Death during follow-up was recorded. Results: At baseline, atrial fibrillation, angiotensin inhibitors and betablockers & MV flail were observed in 21%, 55%, 40% & 45%, while mean STS score, logBNP, MV efective regurgitant orifice, LVEF, right ventricular systolic pressure & LV-GLS were 4.1±1, 4.1±1, 0.55±0.2 cm2, 62±2%, 37±15 mm Hg & -20.6±2%. 92% underwent MV repair (11% with coronary bypass) & 94 (21%) had abnormal post-op LVEF. At 7.7±2 years, there were 30 (7%) deaths. Figure 1a shows logistic regression of association between abnormal post-op LVEF & various factors. On multivariable Cox survival analysis, higher STS score (Hazard ratio or HR 1.55), lower LV-GLS (HR 1.17) & higher logBNP (HR 2.26) were independent predictors of long-term mortality (all p<0.05). Figure 1 b-c shows curves for long-term survival, based on LV-GLS & log-BNP better or worse than median. Conclusions: In asymptomatic patients with ≥3+ PMR & baseline LVEF ≥60% who underwent MV surgery, lower baseline LV-GLS & higher logBNP were associated with abnormal post-op LVEF. Both, higher logBNP & LV-GLS were associated with higher long-term mortality.