Mild mitral regurgitation was associated with increased prevalence of thromboembolic events in patients with nonrheumatic atrial fibrillation

Although several studies demonstrated that the presence of significant mitr al regurgitation was associated with reduced occurrence of thromboembolism, little data is available concerning the effect of mild mitral regurgitatio n on the occurrence of thromboembolic events. To evaluate the association b etween mild mitral regurgitation and thromboembolic events, we reviewed 232 patients' records between January 1996 and September 1997 who had nonrheum atic atrial fibrillation. There were 59 patients (25%) with mitral regurgit ation greater than or equal to grade 2, 69 patients (30%) with grade 1 mitr al regurgitation, and 104 patients (45%) with no mitral regurgitation. Pati ents with grade 1 mitral regurgitation had significantly higher prevalence of thromboembolic events (28%) than those with mitral regurgitation greater than or equal to grade 2 (8%, P=0.006) or those with no mitral regurgitati on (11%, P=0.007). A history of previous thromboembolic events were compare d between 173 patients with grade 1 mitral regurgitation and those with no mitral regurgitation using the logistic regression analysis adjusted for ag e, sex, administration of warfarin, and presence of hypertension, diabetes mellitus, structural heart disease, enlarged left atrium (greater than or e qual to 40 mm), chronic atrial fibrillation, and grade 1 mitral regurgitati on. Grade 1 mitral regurgitation (odds ratio=2.689, 95% confidence interval =1.039-7.189, P=0.0434) and no warfarin administration (odds ratio=0.045, 9 5% confidence interval=0.002-0.242, P=0.0036) were significantly associated with the history of thromboembolic events, The presence of mild mitral reg urgitation in nonrheumatic atrial fibrillation was associated with higher p revalence of thromboembolic events. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.