Prognostic Value of Global Longitudinal Strain and Etiology After Surgery for Primary Mitral Regurgitation

Abstract

Objectives: This study sought to investigate whether left ventricular (LV) global longitudinal strain (GLS) is associated with long-term outcome after mitral valve (MV) surgery for primary mitral regurgitation (MR) and assess the differences in outcome according to MR etiology: Barlow's disease (BD), fibroelastic deficiency (FED), and forme fruste (FF).

Background: Appropriate timing of MV surgery for primary MR is still challenging and may differ according to the etiology. In these patients, LV-GLS has been proposed as more sensitive measure to detect subtle LV dysfunction as compared with LV ejection fraction.

Methods: Echocardiography was performed in 593 patients (64% men, age 65 ± 12 years) with severe primary MR who underwent MV surgery, including assessment of LV-GLS. The etiology (BD, FED, or FF) was defined based on surgical observation. During follow-up, primary endpoint was all-cause mortality and a secondary endpoint included cardiovascular death, heart failure hospitalizations, and cerebrovascular accidents.

Results: During a median follow-up of 6.4 (interquartile range: 3.6 to 10.4) years, 146 patients died (16 within 30 days after surgery), 46 patients were hospitalized for heart failure, and 13 patients had a cerebrovascular accident. Age (hazard ratio [HR]: 1.08; 95% confidence interval [CI]: 1.05 to 1.11; p < 0.001) and LV-GLS (HR: 1.13; 95% CI: 1.06 to 1.21; p < 0.001) were independently associated with all-cause mortality. Patients with LV-GLS >-20.6% (more impaired) showed significant worse survival than did patients with LV-GLS ≤-20.6%; of interest, patients with BD showed similar prognosis compared with FED and FF. In addition, previous atrial fibrillation (HR: 1.70; 95% CI: 1.01 to 2.86; p = 0.045) and LV-GLS (HR: 1.01; 95% CI: 1.01 to 1.15; p = 0.019) were independently associated with the secondary endpoint.

Conclusions: LV-GLS is independently associated with all-cause mortality and cardiovascular events after MV surgery for primary MR and might be helpful to guide surgical timing. Importantly, patients with BD showed similar prognosis when corrected for age, compared with patients with FED or FF.

Keywords: Barlow’s disease; fibroelastic deficiency; global longitudinal strain; primary mitral regurgitation; prognosis.