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Background: Reduced-dose rivaroxaban (10 mg) was used in the J-ROCKET AF trial, demonstrating safety in the Asian population. It remains unclear whether treatment with reduced-dose versus full-dose rivaroxaban (20 mg/15 mg) is associated with all-cause mortality in older patients with nonvalvular atrial fibrillation. Proposed: To evaluate the effects of reduced-dose rivaroxaban on all-cause mortality in patients over 85. Methods: We retrospectively enrolled medical records representing the period from October 2012 to November 2016. The 2 × 2 factorial design incorporated age (≥85 vs. <85) and rivaroxaban use (reduced vs. full dose). The primary study outcomes were all-cause and cardiac-related mortality. Results: The study enrolled 2386 patients with a mean age of 76.6 ± 10.4 years; 51.8% were male. In the ≥85 group (n = 593), the reduced-dose subgroup had lower all-cause (5.3% vs. 10.6%, p = 0.02) and cardiac-related mortality (1.9% vs. 5.1%, p = 0.04), whereas the younger patients receiving reduced-dose rivaroxaban had higher all-cause mortality (3.7% vs. 1.8%, p = 0.01) but no difference in cardiac-related mortality (1.2% vs. 0.7%, p = 0.33). The rate of hospitalization for heart failure was significantly lower in the elderly group with reduced-dose rivaroxaban (7.2% vs. 15.7%, p < 0.01) but not in the younger group. After adjusting for confounders in the older group, treatment with reduced-dose rivaroxaban was associated with lower risk of all-cause mortality (adjusted HR (aHR): 0.40, 95% CI: 0.21–0.74, p < 0.01) and hospitalization for heart failure (aHR: 0.54, 95% CI: 0.29–0.99, p = 0.05). No associations were found between rivaroxaban dose and cardiac-related mortality in either group, nor between younger age and any outcome. Conclusions: Reduced-dose rivaroxaban was associated with lower risks of all-cause mortality and hospitalization for heart failure in older patients with nonvalvular atrial fibrillation. Future studies can investigate the effect of reduced-dose rivaroxaban on prognoses in elderly individuals ≥85 years in the west. [ABSTRACT FROM AUTHOR]

Introduction: Rivaroxaban reduces the risk of thromboembolism in atrial fibrillation (AF) patients, who often also receive antiarrhythmic drugs (AADs) to maintain sinus rhythm. Current guidelines contraindicate concomitant use of rivaroxaban with the popular AAD dronedarone, despite little data demonstrating interactions with AADs. This study investigates the outcomes of concomitant rivaroxaban and AAD drug use in a real-world cohort. Methods: This retrospective study included 1777 non-permanent AF patients taking rivaroxaban for ≥ 1 month between 2011 and 2016 from a multicenter cohort in Taiwan, and compared concomitant AAD use against clinical outcome endpoints for safety, effectiveness, and major adverse cardiac events (MACE). Multivariate Cox proportional hazard analyses were used to evaluate the association between concomitant AAD use and outcomes. Results: Patients were divided into rivaroxaban alone (n = 1205) and with concomitant amiodarone (n = 177), dronedarone (n = 231), or propafenone (n = 164) groups. The proportion of patients using rivaroxaban 10 mg was highest in the concomitant dronedarone group: rivaroxaban alone, 53.6%; with amiodarone, 57.6%; with dronedarone, 77.1%; and with propafenone, 46.3% (p < 0.001). The cumulative incidences of safety (p = 0.892), effectiveness (p = 0.336), and MACE (p = 0.674) were similar between the four groups; however, there were significantly fewer new systemic thromboembolisms in the dronedarone group: rivaroxaban alone, 2.5%; with amiodarone, 0.6%; with dronedarone, 0%; and with propafenone, 1.2% (p = 0.029). The all-cause death rate was also lowest in the dronedarone group: rivaroxaban alone, 9.0%; with amiodarone, 9.6%; with dronedarone, 3.0%; and with propafenone: 6.1% (p = 0.013). After covariate adjustment, there were no differences in the safety, effectiveness, and MACE endpoints between patients receiving or not receiving AADs. Conclusion: Concomitant use of rivaroxaban with AADs appears to be well tolerated, warranting further investigation into the apparent benefits of a reduced dose of rivaroxaban combined with dronedarone. [ABSTRACT FROM AUTHOR]

The emerging data supports rhythm control to prevent major adverse cardiac events (MACE) in high-risk patients with atrial fibrillation (AF). Limited data demonstrated rivaroxaban 10 mg combining dronedarone seemed feasible. This study aimed at investigating clinical events in a dronedarone-treated cohort. This exploratory, retrospective chart review was conducted in nonpermanent AF patients receiving dronedarone for ≥ 3 months between 2009/1 and 2016/2. In Taiwan, dronedarone's labeled indication was strict to age ≥ 70 or 65 to 70 years with either hypertension, diabetes, prior stroke, or left atrium >50 mm. We divided all into 4 groups using antithrombotic strategies to evaluate the safety, effectiveness, and MACE endpoints. A total of 689 patients (mean CHA2DS2-VASc score 3.8 ± 1.4) were analyzed: rivaroxaban 10 mg (n = 93, 13.5%), warfarin (n = 89, 12.9%), antiplatelet (n = 331, 48.0%), and none (n = 176, 25.5%). During the follow-up period (mean 946 ± 493.8 days), the rivaroxaban group did not report any stroke or thromboembolism (ishcmeic stroke rate: antiplatelet [0.6%], none [1.1%]; hemorrahgic stroke rate: warfarin [2.2%]; thromboembolism rate: warfarin [2.2%]). There was no significant difference in safety, effectiveness, and MACE endpoints between groups. Also, >104 weeks of dronedarone use was the independent predictor for MACE after adjusting the strategy and other covariates (hazard ratio 0.14 [95% confidence interval 0.04-0.44], P =.001). Our findings warrant concomitant rivaroxaban 10 mg and dronedarone for further investigation. Regardless of antithrombotic strategies, a more extended persistence of dronedarone was associated with fewer MACE. [ABSTRACT FROM AUTHOR]