Significant mitral regurgitation is protective against left atrial spontaneous echo contrast and thrombus as assessed by transesophageal echocardiography.

This retrospective study examines whether a relationship exists between the severity of mitral regurgitation (MR) and the presence of left atrial spontaneous echo contrast and/or thrombus (SEC/THR) as assessed by transesophageal echocardiography in 427 consecutive patients. Clinical data were evaluated in 316 of these patients. Nine percent of patients with MR < or = 2+ versus < 1% of those with MR > or = 3+ had SEC/THR (p < 0.03). Atrial fibrillation, left ventricular dysfunction, mitral stenosis, and mitral valve prosthesis were demonstrated to be independent positive predictors of left atrial SEC/THR, whereas MR > or = 3+ was an independent negative predictor of SEC/THR. SEC/THR was less common in patients with MR > or = 3+ than in patients with MR < or = 2+ for any given number of independent positive predictors of SEC/THR. This relationship did not hold true in patients with a mechanical mitral prosthetic valve. Clinical data revealed a trend towards a lower prevalence of stroke or transient ischemic attacks in patients with MR > or = 3+. Stroke and transient ischemic attacks were significantly more common in patients with SEC/THR (p < 0.001). We suggest that significant MR may be protective against the formation of left atrial SEC/THR.