Prophylactic Rivaroxaban Therapy for Left Ventricular Thrombus After Anterior ST-Segment Elevation Myocardial Infarction.

OBJECTIVES: The aim of this study was to investigate the effects of rivaroxaban on left ventricle thromboprophylaxis in patients with anterior ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Anterior STEMI is associated with an increased risk of left ventricular thrombus (LVT) formation. The contemporary role of prophylactic rivaroxaban therapy remains unclear. METHODS: We randomly assigned 279 patients with anterior STEMI who had undergone primary percutaneous coronary intervention to receive, in a 1:1 ratio, low-dose rivaroxaban (2.5 mg twice daily for 30 days) and dual antiplatelet therapy (DAPT) or only DAPT. The primary efficacy outcome was the LVT formation within 30 days. Net clinical adverse events were assessed at 30 days and 180 days, including all-cause mortality, LVT, systemic embolism, rehospitalization for cardiovascular events, and bleeding. RESULTS: The addition of low-dose rivaroxaban to DAPT reduced LVT formation within 30 days compared with only DAPT (0.7% vs 8.6%; HR: 0.08; 95% CI: 0.01-0.62; P = 0.015; P < 0.001 for superiority). Net clinical adverse events were lower within 30 days in the rivaroxaban group versus those in the only DAPT group and remained relatively low throughout the follow-up period. There were no significant differences in bleeding events between the 2 groups in 30 days and 180 days. However, 1 case of intracranial hemorrhage (major bleeding) occurred in the rivaroxaban group within 30 days. CONCLUSIONS: Our results supported that the short-duration addition of low-dose rivaroxaban to DAPT could prevent LVT formation in patients with anterior STEMI following primary percutaneous coronary intervention. A larger multiple-institution study is necessary to determine the generalizability.

Reduced Rivaroxaban Dose Versus Dual Antiplatelet Therapy After Left Atrial Appendage Closure: ADRIFT a Randomized Pilot Study.

BACKGROUND: Percutaneous left atrial appendage closure (LAAC) exposes to the risk of device thrombosis in patients with atrial fibrillation who frequently have a contraindication to full anticoagulation. Thereby, dual antiplatelet therapy (DAPT) is usually preferred. No randomized study has evaluated nonvitamin K antagonist oral anticoagulant after LAAC, and we decided to evaluate the efficacy and safety of reduced doses of rivaroxaban after LAAC. METHODS: ADRIFT (Assessment of Dual Antiplatelet Therapy Versus Rivaroxaban in Atrial Fibrillation Patients Treated With Left Atrial Appendage Closure) is a multicenter, phase IIb study, which randomized 105 patients after successful LAAC to either rivaroxaban 10 mg (R10, n=37), rivaroxaban 15 mg (R15, n=35), or DAPT with aspirin 75 mg and clopidogrel 75 mg (n=33). The primary end point was thrombin generation (prothrombin fragments 1+2) measured 2 to 4 hours after drug intake, 10 days after treatment initiation. Thrombin-antithrombin complex, D-dimers, rivaroxaban concentrations were also measured at 10 days and 3 months. Clinical end points were evaluated at 3-month follow-up. RESULTS: The primary end point was reduced with R10 (179 pmol/L [interquartile range (IQR), 129-273], P<0.0001) and R15 (163 pmol/L [IQR, 112-231], P<0.0001) as compared with DAPT (322 pmol/L [IQR, 218-528]). We observed no significant reduction of the primary end point between R10 and R15 while rivaroxaban concentrations increased significantly from 184 ng/mL (IQR, 127-290) with R10 to 274 ng/mL (IQR, 192-377) with R15, P<0.0001. Thrombin-antithrombin complex and D-dimers were numerically lower with both rivaroxaban doses than with DAPT. These findings were all confirmed at 3 months. The clinical end points were not different between groups. A device thrombosis was noted in 2 patients assigned to DAPT. CONCLUSIONS: Thrombin generation measured after LAAC was lower in patients treated by reduced rivaroxaban doses than DAPT, supporting an alternative to the antithrombotic regimens currently used after LAAC and deserves further evaluation in larger studies. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03273322.