Predictive factors of left atrial spontaneous echo contrast in patients with rheumatic mitral valve stenosis: a retrospective study of 159 patients

Mitral valve stenosis is a common manifestation of chronic rheumatic heart disease. The presence of spontaneous echo contrast in the left atrium and left atrial appendage has been reported to be an independent predictor of thrombo-embolic risk in patients with mitral stenosis. The objective of this study was to retrospectively investigate various clinical and echocardiographic variables to predict the spontaneous echo contrast in these patients. This is a bicentric retrospective study which includes 159 cases of symptomatic mitral stenosis from January 2011 to June 2012. All of the patients had transthoracic and transesophageal echocardiography. Patients who had significant mitral regurgitation (> Grade I), significant aortic valve disease, previous mitral valvulotomy and anticoagulation or antiplatelet therapy were excluded from the study. Our study population was divided into two groups based on the presence (Group I) or absence (Group II) of spontaneous echo contrast. Left atrial spontaneous contrast was present in 34.6% of cases. Patients in this group have more frequent atrial fibrillation (P = 0.001), larger left atrial area (P = 0.027) and diameter (P=0.023), smaller mitral valve area (P = 0.025), and higher mean transmitral diastolic gradient (p = 0.003) as compared to patients without spontaneous echo contrast. There were no significant differences in the mean age (p = 0.38), duration of symptoms (p = 0.4) and left ventricular ejection fraction (p = 0.7) between patients with and without spontaneous echo contrast. On multivariate analysis, only mitral valve area and transmitral diastolic gradient (OR: 18.753, 1.21, CI [1,838-191,332], [1,064-1,376], p: 0.013, 0.004, respectively) were found to be independently associated to the presence of spontaneous echo contrast. Patients with severe rheumatic mitral stenosis in atrial fibrillation or sinus rhythm have a higher risk of developing spontaneous echo contrast. These patients might benefit from prophylactic anticoagulation. The long-term outcomes can be ascertained in a study over a longer period and with periodic follow-up.