Prognostic value of left atrial function in patients with severe primary mitral regurgitation undergoing mitral valve repair

Abstract

Abstract Background Timing of mitral valve surgery for primary mitral regurgitation (MR) remains challenging. Since MR has a significant hemodynamic impact on the left atrium (LA), assessment of LA function may have prognostic value in these patients which is incremental to LA volume and left ventricular (LV) remodeling parameters. Purpose This study sought to investigate whether preoperative assessment of LA reservoir strain (LASr) by speckle tracking echocardiography is associated with long-term outcome in patients undergoing mitral valve repair for severe primary MR. Methods Echocardiography was performed prior to mitral valve surgery in 566 patients (age 64±12 years, 66% men) with severe primary MR. Complete clinical information was collected and the endpoint was all-cause mortality after operation. The study population was divided based on a cut-off value of LASr (22%) derived from a spline curve analysis (hazard ratio for all-cause mortality >1). Results Patients with LASr ≤22% (n=277) were significantly older, had more impaired renal function and were more symptomatic (NYHA functional class III to IV) compared to patients with LASr >22% (n=289). In terms of echocardiographic data, patients with LASr ≤22% had significantly lower LV ejection fraction and LV global longitudinal strain (LV-GLS) and significantly higher systolic pulmonary artery pressures and LA volume index compared with patients with LASr >22%. During a median follow-up of 95 (56 – 147) months, 129 patients (22.8%) died. Patients with LASr ≤22% experienced significantly higher mortality rates compared to patients with LASr >22% (log rank chi-square 35.1; p<0.001) (Figure). On multivariable analysis, age (hazard ratio (HR): 1.06; 95% confidence interval (CI): 1.03 to 1.09; p<0.001), LV-GLS (HR: 1.08; 95% CI: 1.02 to 1.15; p=0.014) and LASr (HR: 0.96; 95% CI: 0.93 to 0.99; p=0.014) were independently associated with all-cause mortality. The addition of LASr to a clinical model (including: age, coronary artery disease, estimated glomerular filtration rate, NYHA class III-IV, atrial fibrillation, LV end-diastolic volume index, LV ejection fraction, LV-GLS, LA volume index and systolic pulmonary artery pressure) showed a significant increase in the chi-square value (chi-square differences = 6.9; p=0.011), demonstrating the incremental prognostic value of LASr in patients with primary MR. Conclusions Preoperative LASr is independently associated with all-cause mortality in patients undergoing mitral valve repair for primary MR, has incremental prognostic value over LA volume and LVEF and might therefore be helpful to guide surgical timing. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Jan Stassen has received an ESC training grant (Appehab724.011364741) Association of LASr and outcome