The presence of spontaneous echo contrast didn't increase the risk for left atrial appendage closure: A propensity score matching analysis based on the CLACBAC study

Left atrial appendage closure (LAAC) was effective in preventing thromboembolic events and stroke in patients with atrial fibrillation (AF). However, whether left atrial spontaneous echo contrast (LA-SEC) poses a higher risk for thromboembolism is contradictory. We aimed to investigate whether LA-SEC is a risk factor for thromboembolic events in patients who underwent LAAC. 258 consecutive patients who underwent successful LAAC were enrolled and divided according to the presence or absence of LA-SEC detected by transesophageal echocardiography (TEE). Propensity score matching (PSM) was used to eliminate covariate imbalances. Baseline characteristics, periprocedural details, and clinical outcomes were compared between LA-SEC and non-LA-SEC groups and PSM-matched groups. Of the 258 patients enrolled, mean age was 71.8 ± 8.3 years and 59.3 % were male. LA-SEC group had a higher percentage of persistent AF and worse cardiac function. No significant difference in peri-procedure parameters was found. Through follow-up of 38.1 ± 10.7 months, the total incidence of thromboembolic events and stroke was 7.8 % and 6.6 %, respectively. Though the event-free survival rate of thromboembolic events (Log-Rank P = 0.042) and stroke (Log-Rank P = 0.010) was significantly lower in the LA-SEC group, multivariable COX regression analysis showed LA-SEC was not an independent predictor of thromboembolic events (Hazard ratio 2.073, 95 % Confidence interval 0.845–5.082, P = 0.111). Further survival analysis between PSM-matched groups with comparable baseline characteristics presented no significant difference in survival free from thromboembolic events (Log-Rank P = 0.616) and stroke (Log-Rank P = 0.312). Patients with LA-SEC had worse condition, while LA-SEC per se did not increase the incidence of thromboembolic events and stroke for patients who underwent LAAC.