Background: Mild secondary mitral regurgitation (SMR) is considered clinically benign when left-ventricular ejection fraction (LVEF) is preserved, but evidence on survival associated with mild SMR in normal LVEF is limited.
Methods: We conducted a retrospective cohort study of patients who underwent echocardiography in a health care network between 2013 and 2018. We compared the survival of 4 groups: no valvular abnormalities (group 1), trace SMR with trace or mild tricuspid regurgitation (TR) (group 2), mild SMR with trace or no TR (group 3), and mild SMR with mild TR (group 4). A Cox proportional hazard model evaluated hazard of death in groups 2 to 4 compared with group 1, adjusting for demographics, comorbidities, and LVEF. The same comparisons were repeated in a subgroup of patients with preserved LVEF.
Results: Among the 16,372 patients of mean age 61 (51 to 71) years and 48% women, there were 8132 (49.7%) group 1 patients, 1902 (11.6%) group 2 patients, 3017 (18.4%) group 3 patients, and 3321 (20.3%) group 4 patients. Compared with group 1, group 4 had significantly increased adjusted hazard of death (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.12-1.31; P < 0.001), whereas groups 2 and 3 did not show a significantly different hazard of death. In those with preserved LVEF, the hazard was also significantly higher in group 4, compared with group 1 (HR, 1.14; 95% CI, 1.03-1.26; P = 0.013).
Conclusions: Mild SMR with mild TR, irrespective of LVEF, was associated with worse survival compared with patients without any valvular abnormalities. Patients with mild SMR may require closer monitoring, even with normal LVEF.
Copyright © 2021 Canadian Cardiovascular Society. All rights reserved.