Left atrial strain as a pre-operative prognostic marker for patients with severe primary mitral regurgitation

Abstract

Abstract Background For patients with severe mitral regurgitation (MR), new indices are needed to optimize surgical timing before irreversible myocardial dysfunction. Purpose We investigated the prognostic role of left atrial (LA) strain by speckle tracking echocardiography after mitral surgery for severe MR, and its association with LA fibrosis. Methods 70 patients with primary severe MR undergoing echocardiography before mitral surgery were enrolled. Patients with other valvular disease > moderate, left bundle branch block, coronary artery disease, heart failure (HF), pacemaker implantation, heart transplantation, poor acoustic window, were excluded. The primary composite endpoint included HF and mortality; the secondary endpoint was post-operative functional capacity (NYHA and Borg CR10). LA fibrosis was assessed by atrial biopsy specimens. Results Of 62 patients eligible, 32 had composite events (medium follow-up: 3.3±2.5 years for event-group, 7.6±1 years for non-event group). Characteristics of our study population are summarized in Table 1. With Kaplan-Meier analysis (Fig. 1), PALS provided a good risk stratification; it also was an independent and incremental predictor of outcome in four multivariate Cox adjusted models. There was a strong association between PALS and secondary endpoint (NYHA: r2=0.11, p=0.04; Borg CR10: r2=0.10, p=0.02) and an inverse correlation between PALS <21% and LA fibrosis (r2=0.80; 76.6±20.7% vs 31.9±20.8%; p<0.0001). Conclusions Global PALS emerged as a reliable predictor of outcome and functional capacity for severe primary MR, and as a marker of LA fibrosis. Figure 1 Funding Acknowledgement Type of funding source: None