Abstract 222: Natural History of Asymptomatic Severe Degenerative Mitral Regurgitation
Many asymptomatic patients with severe degenerative mitral regurgitation (DMR) and preserved left ventricular (LV) function remain stable for many years, but others develop symptoms, left ventricular dysfunction or new onset of atrial fibrillation (AF) or elevated pulmonary artery pressure (EPAP) and require surgery, according to AHA guidelines.
Purpose: To identify the term course and predictors of symptoms development and LV dysfunction leading to surgery in patients with asymptomatic DMR and preserved LV function.
Methods: Prospective study of a cohort of asymptomatic patients with preserved LV function and severe DMR (presence of prolapse or flail leaflet) with a follow-up ≥1 year. Surgical criteria were established according to AHA guidelines. Clinical and echocardiographic follow-up was performed at least every year and more frequently when it was clinically needed.
Results: 114 patients (64% M, 36% f; 61±13 y) with DMR were followed-up during 6±5.9 years (1–20 years). Valve anatomy was as follows: 30% anterior (AVP), 54% posterior (PVP) and 16% both leaflets were involved. Flail leaflet was present in 39.8% of patients. Left ventricle diameters at beginning of follow-up were: EDD 56.41±7.8 mm; ESD 34±6 mm and EF 61.8%. By Kaplan-Meier curves analysis, 58.8±5.5% of patients remained asymptomatic with normal ejection fraction at 5 years and 40.7±6.3% estimated at 10 years, with an average attrition rate of less than 2% per year. Surgery was indicated in 52 (45.6%) patients: 28 symptoms, 11 developed asymptomatic LV dysfunction and 13 presented new onset of AF or EPAP. Two patients died during follow-up. By univariate Cox regression analysis, sex (HR 2.1; 95% IC 1.1–3.9, p=0.03) and ESD (HR 1.1; 95% IC 1.1–1.2, p=0.021) were associated with symptoms or death. Changes in ESD were associated with symptoms or death. At final follow-up 49 patients were in CF I and 11 patients in CF II with EDD 55.5±7.9 mm, ESD 33.3±5.9 and EF 63.4±7.6%.
Conclusions: Our study suggest that DMR is a slow but progressive disease that deserves a strict clinical an echocardiographic follow-up. Changes in end-systolic diameter indicate a risk for develop symptoms and progressive LV dysfunction.