Predictive Factors of DRT After LAAO: International Multicenter Data

The study included 237 patients with DRT from 37 centers (DRT group), with each patient matched with 2 patients from the same center who had the same type of occluder implanted and no DRT after the procedure (control group, n=474). The objectives of the study included: (1) DRT management strategies; (2) mid-term follow-up results, including major adverse cardiovascular events (MACE), bleeding events, and intracranial hemorrhage; (3) predictive factors for DRT. The DRT group had a higher proportion of hypertension, heart failure, previous stroke, history of venous thromboembolism, hypercoagulable state diseases, and non-paroxysmal atrial fibrillation compared to the control group (Table 1). There were no significant differences in the left atrial appendage morphology between the two groups, with approximately 80% of patients undergoing transesophageal echocardiography-guided procedures, and 74% of patients implanted with the Watchman occluder (Figure 1 and Table 2). The DRT group had a deeper occluder implantation position (12.0±8.4mm vs. 8.2±6.5mm, P<0.001) and a higher incidence of pericardial effusion during the perioperative period (3.4% vs. 0.6%, P=0.01) (Table 2).

During follow-up, the DRT group had higher rates of device displacement (2.7% vs. 0.0%, P=0.002) and residual shunting from the occluder (34.6% vs. 26.1%, P=0.005) (Table 3). The proportions of DRT found at postoperative <45d, 45-180d, 180-365d, and >365d were 24.9%, 38.8%, 16.0%, and 20.3%, respectively. The DRT group underwent imaging examinations more frequently and had a higher incidence of MACE (Figure 2). There were no statistical differences in the choice of antithrombotic drugs between the two groups after surgery, with most patients using single antiplatelet therapy (36.3%) or dual antiplatelet therapy (26.2%) when DRT was detected, followed by a significant increase in anticoagulation therapy, but 25.3% of patients still had DRT at the last follow-up (Figure 3). The median follow-up times for the DRT group and control group were 1.8 years and 1.6 years, respectively, with the DRT group having a higher incidence of MACE (29.5% vs. 3.6%, HR=3.49, P=0.01), where the incidence of ischemic stroke was also higher in the DRT group (16.9% vs. 3.6%, HR=3.49, P=0.01), while there were no significant differences in all-cause mortality and systemic embolism rates between the two groups (Figure 4). Additionally, the rates of bleeding events and intracranial hemorrhage were comparable between the two groups (Figure 5). For patients with both DRT and ischemic stroke, the study found that 59% of DRT cases were detected before the stroke occurred (Figure 6).

Multivariate analysis found that predictive factors for DRT included hypercoagulable state diseases (OR=17.50), pericardial effusion (OR=13.45), renal insufficiency (OR=4.02), occluder implantation distance greater than 10mm from the pulmonary veins (OR=2.41), and non-paroxysmal atrial fibrillation (OR=1.90) (Figure 7). After scoring these predictive factors, a DRT risk scoring system was established, where hypercoagulable state diseases and pericardial effusion each scored 4 points, renal insufficiency, occluder implantation distance greater than 10mm, and non-paroxysmal atrial fibrillation each scored 1 point, with total scores of 0-1 points indicating low risk for DRT and ≥2 points indicating high risk for DRT (Figure 8).

This study shows that DRT after LAAO increases the risk of ischemic stroke. Some factors can predict DRT, and stratifying DRT risk based on these factors can facilitate perioperative and postoperative management.