Risk Stratification and Mortality in Mitral Stenosis Patients

Abstract

Background: Rheumatic mitral stenosis is the most common valvular abnormalities found in developing countries. Mortality risk in those populations was poorly investigated. In addition, hemodynamic, morphological, and mechanical factors that influence or predict outcome of rheumatic mitral stenosis have not been identified.

Aims: To determine predictive factors affecting outcome in rheumatic mitral stenosis patients.

Method: This retrospective cohort study was conducted at the National General Hospital Dr. Sardjito, Yogyakarta, Indonesia. The study recruited patients from the Valvular Heart Disease Registry from May 2014 to November 2020. New York Heart Association (NYHA) functional classification, invasive or surgical treatment, and incidence of death were recorded. The baseline rhythm from electrocardiography (ECG) was categorized as sinus rhythm and atrial fibrillation or atrial flutter. Based on the findings of trans thoracal echocardiography (TTE), subjects who had moderate to severe pure rheumatic mitral stenosis (or followed by mitral regurgitation and / or less significant tricuspid regurgitation as a natural history) and subjects with rheumatic mitral stenosis with a combination of other heart valve problems (of which severity more significantly) classified as groups I and II. The mitral valve area (MVA), mitral valve gradient (MVG), left atrial diameter (LA), and mean pulmonary artery pressure (mPAP) were then analyzed.

Results: A total of 477 patients (mean age 44.08 ± 10.93 years; 71.5% female) were enrolled in this study. There were 61 deaths during the median follow up of 393 days of which 35 deaths occurred in group I and 26 deaths occurred in group II. Kaplan Meier curve shows the 1 year survival rate is higher in group I than group II which is 92.5% and 92%, respectively. Bivariate followed by multivariate analysis showed MVG and mPAP were predictive risk factors for mortality in group I with p = 0.020 and p = 0.021. MVG parameter values evaluated from echocardiography with a cut-off of more than 10 mmHg and mPAP parameters with a cut-off of more than 50 mmHg were independent predictive risk factors for mortality. Thus, patients were at higher risk of death if MVG > 10 mmHg and mPAP > 50 mmHg

Conclusion: One year survival rate in group I was higher than group II. MVG and mPAP were risk factors for predicting mortality in group I.