Abstract 15202: Functional Mitral Regurgitation is a Quantitative Determinant of Mortality in Patients With Left Ventricular Dysfunction in Clinical Practice
Background: Functional mitral regurgitation (FMR) grading in left ventricular (LV) dysfunction is controversial. Pilot studies suggested mortality-risk at low effective regurgitant orifice (ERO) but actual risks over entire spectrums of FMR and ejection fraction (EF) is undefined. Hence, we examined FMR impact, assessed by multiple practitioners over complete LV dysfunction spectrum.
Methods: We enrolled all patients ≥50 years diagnosed with LV dysfunction (EF <50%) at Mayo Clinic between 2003 and 2012 with ERO calculation for FMR. Organic valve disease, previous valve surgery, congenital, hypertrophic or infiltrative myocardial diseases and cancer history were excluded.
Results: Of 6381 patients with LV dysfunction enrolled, 3825 had no/trivial FMR and in those with quantified FMR, ERO was 0.22±0.12 cm2. During long-term follow-up 3538 patients died, 86% under medical treatment and 14% post cardiac surgery or defibrillator implantation. Simple FMR presence determined excess-mortality univariately (RR 1.55, 95%CI [1.45-1.65], p<0.0001) and adjusting for age, gender, EF, atrial fibrillation and comorbidities (RR 1.36, 95%CI [1.26-1.46], p<0.0001). ERO as continuous variable superseded standard categorical FMR grading and independently determined mortality (RR 3.95 [3.05-5.09] per cm2, p<0.0001). Examined for each 0.1 cm2 ERO increment (Figure), excess long-term mortality (vs. no FMR) appears for small ERO (≥0.1 cm2) and continues to increase even beyond the guideline-based 0.2 cm2. The 1-year mortality under medical management was 13% for patients without FMR, 15% for ERO 0.01-0.19, 20% for ERO 0.20-0.39 and 37% for ERO ≥0.40 cm2.
Conclusion: This large study shows that FMR exhibits an independent and quantitative impact on survival over entire LV dysfunction spectrum. Each ERO increment measured in routine clinical practice adds mortality-risk short and long-term. These novel insights should be considered in clinical trials of FMR treatment.
Author Disclosures: G. Benfari: None. C. Antoine: None. W.L. Miller: None. H.I. Michelena: None. V.T. Nkomo: None. M. Enriquez-Sarano: None.
- © 2016 by American Heart Association, Inc.