Long-term left atrial thrombi after mitral valve replacement

The aim of this study was to evaluate the risk factors and characteristics of long-term postoperative left atrial (LA) thrombi after mitral valve replacement. Transthoracic echocardiography (TTE) file of 3117 consecutive patients with mitral valve replacement history was reviewed (between Jan 2006 and Feb 2019). 45 LA thrombi cases (1.4%) was identified and matched to 180 thrombi-free cases by random sampling. The median detection time of LA thrombi was 58 months (IQR, 17-144) after MV replacement. Distribution of LA thrombi included roof (n = 10), posterior wall (n = 9), appendage (n = 7), lateral wall (n = 6), anterior wall (n = 2), septum (n = 1) and multiple site (n = 10). All thrombi were sessile and immobile. The independent predictors for LA thrombi development by stepwise multiple regression analysis were the larger LA size (> 55 mm), the increased of mitral valve pressure gradient (MVPG > 6 mmHg), and the reduced of left ventricular ejection fraction (LVEF < 50%). Long-term thrombi incidence after mitral valve replacement is somewhat low. In individuals with mitral prosthetic valves, larger LA size, increased MVPG and reduced LVEF were three promising independent predictors of the insistence of LA thrombi. Furthermore, LA thrombi were sessile, immobile and widespread in the long-term postoperative period after mitral valve replacement. Close monitoring should be applied in these patients with thrombi risk.