271 patients with permanent AF underwent transesophageal echocardiography (TEE). The severity of MR was assessed by Doppler echocardiography. LA blood stasis on TEE and plasma D-dimer levels were used to evaluate the thromboembolic risk.
Patients with severe MR (n = 20) had significantly higher LA appendage peak flow velocity compared to those with no MR (n = 114) and those with only mild MR (n = 92) (p < 0.05). The grade of LA spontaneous echo contrast (SEC) was lower in patients with severe MR compared to those with no, mild or moderate MR (severe MR 0.7 ± 0.7 grade vs moderate MR 1.7 ± 1.0 grade, mild MR 2.2 ± 1.3 grade, and no MR 1.9 ± 1.3 grade, p < 0.05). Multivariate analysis revealed severe MR as a negative predictor of LA blood stasis on TEE findings (odds ratio 0.27; 95 % confidence interval 0.09-0.86, p < 0.05). By contrast, D-dimer level was significantly higher in patients with moderate MR compared to those with any other type of severity of MR (moderate MR 1.72 ± 1.45 µg/ml vs severe MR 0.76 ± 0.95 µg/ml, mild MR 0.97 ± 1.09 µg/ml, and no MR 0.82 ± 1.15 µg/ml, p < 0.05).
There is a protective effect of MR on LA blood stasis, but this beneficial effect on thromboembolic risk appears to be limited to patients with severe MR.