Short-Term Oral Anticoagulation Versus Antiplatelet Therapy Following Transcatheter Left Atrial Appendage Closure.

BACKGROUND

The impact of antithrombotic therapy on coagulation system activation after left atrial appendage closure (LAAC) remains unknown. This study sought to compare changes in coagulation markers associated with short-term oral anticoagulation (OAC) versus antiplatelet therapy (APT) following LAAC.

METHODS

Prospective study including 78 atrial fibrillation patients undergoing LAAC with the Watchman device. F1+2 (prothrombin fragment 1+2) and TAT (thrombin-antithrombin III) were assessed immediately before the procedure, and at 7, 30, and 180 days after LAAC.

RESULTS

Forty-eight patients were discharged on APT (dual: 31, single: 17) and 30 on OAC (direct anticoagulants: 26, vitamin K antagonists: 4), with no differences in baseline-procedural characteristics between groups except for higher spontaneous echocardiography contrast in the OAC group. OAC significantly reduced coagulation activation within 7 days post-LAAC compared with APT (23% [95% CI, 5%-41%] versus 82% [95% CI, 54%-111%] increase for F1+2, =0.007; 52% [95% CI, 15%-89%] versus 183% [95% CI, 118%-248%] increase for TAT, =0.048), with all patients in both groups progressively returning to baseline values at 30 and 180 days. Spontaneous echocardiography contrast pre-LAAC was associated with an enhanced activation of the coagulation system post-LAAC (144 [48-192] versus 52 [24-111] nmol/L, =0.062 for F1+2; 299 [254-390] versus 78 [19-240] ng/mL, =0.002 for TAT). Device-related thrombosis occurred in 5 patients (6.4%), and all of them were receiving APT at the time of transesophageal echocardiography (10.2% versus 0% if OAC at the time of transesophageal echocardiography, =0.151). Patients with device thrombosis exhibited a greater coagulation activation 7 days post-LAAC (=0.038 and =0.108 for F1+2 and TAT, respectively).

CONCLUSIONS

OAC (versus APT) was associated with a significant attenuation of coagulation system activation post-LAAC. Spontaneous echocardiography contrast pre-LAAC associated with enhanced coagulation activation post-LAAC, which in turn increased the risk of device thrombosis. These results highlight the urgent need for randomized trials comparing OAC versus APT post-LAAC.