Clinical Pearls & Morning Reports
Dangas et al. conducted a randomized, open-label, event-driven, multicenter trial that investigated the role of a treatment strategy including anticoagulation with rivaroxaban as compared with an antiplatelet strategy in patients without established indications for anticoagulation after successful transcatheter aortic-valve replacement (TAVR). Read the Original Article here.
Q: What do current practice guidelines recommend to reduce the risk of thromboembolic complications after TAVR?
A: Thromboembolic complications (stroke, systemic embolism, valve thrombosis, and venous thromboembolism) have been observed after TAVR. Observational data suggest that subclinical leaflet thrombosis may occur with bioprosthetic valves and that this phenomenon may be associated with an increased risk of cerebrovascular events and prevented or reversed by anticoagulation. Current practice guidelines recommend the use of dual antiplatelet therapy early after TAVR, although the recommendation is based mainly on expert consensus.
Q: What dose of rivaroxaban was used in the anticoagulation group in the trial by Dangas et al.?
A: The anticoagulant (experimental) group was assigned to receive rivaroxaban at a dose of 10 mg daily plus aspirin at a dose of 75 to 100 mg daily for 3 months, followed by rivaroxaban monotherapy (10 mg daily).
A: The trial was terminated prematurely by the data and safety monitoring board because of safety concerns. Anticoagulation with rivaroxaban was associated with a higher risk of death or thromboembolic complications and a higher risk of bleeding than an antiplatelet-based strategy. In the intention-to-treat analysis, death or first thromboembolic event (the primary efficacy outcome) occurred in 105 patients in the rivaroxaban group and in 78 patients in the antiplatelet group (incidence rates, 9.8 and 7.2 per 100 person-years, respectively; hazard ratio with rivaroxaban, 1.35; 95% confidence interval [CI], 1.01 to 1.81; P=0.04). A total of 64 deaths occurred in the rivaroxaban group and 38 in the antiplatelet group (incidence rates, 5.8 and 3.4 per 100 person-years, respectively; hazard ratio, 1.69; 95% CI, 1.13 to 2.53). In the intention-to-treat analysis, life-threatening, disabling, or major bleeding (the primary safety outcome) occurred in 46 patients in the rivaroxaban group and 31 patients in the antiplatelet group (incidence rates, 4.3 and 2.8 per 100 person-years, respectively; hazard ratio with rivaroxaban, 1.50; 95% CI, 0.95 to 2.37; P=0.08).
A: The higher number of deaths in the rivaroxaban group than in the antiplatelet group did not appear to be directly attributable to the higher risk of bleeding in the rivaroxaban group. Most of the adjudicated causes of death in the rivaroxaban group were sudden or from unknown reasons, as well as due to noncardiovascular causes. Hence, the mechanism underlying the higher mortality in the rivaroxaban group observed in the intention-to-treat analysis in this trial is unclear.