Direct comparative effectiveness and safety between non-vitamin K antagonist oral anticoagulants for stroke prevention in nonvalvular atrial fibrillation: a systematic review and meta-analysis of observational studies

The non-vitamin K antagonist oral anticoagulants (NOACs) have been increasingly prescribed in clinical practice for stroke prevention in patients with nonvalvular atrial fibrillation (AF). Direct comparisons between NOACs in trials are lacking, leaving an important clinical decision-making gap. We aimed to perform a systematic review and meta-analysis to summarize the evidence of observational studies for direct comparative effectiveness and safety amongst NOACs in patients with AF. Conference proceedings and electronic databases including MEDLINE, CINAHL, EMBASE and PUBMED were systematically searched. We included observational studies directly comparing individual NOACs in patients with nonvalvular AF who were aged ≥ 18 years for stroke prevention. Primary outcome included effectiveness outcome (stroke or systemic embolism) and safety outcome (major bleeding). Data were extracted in duplicated by two reviewers independently. A random-effects meta-analysis was conducted to synthesize the data from included observational studies. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) to rate the overall quality of evidence for each outcome. Fifteen studies were included for qualitative synthesis, twelve studies for meta-analyses. It was found that rivaroxaban and dabigatran were similar with regard to risk of stroke or systemic embolism (Hazard ratio [HR] = 1.00, 95% CI 0.91–1.10; evidence quality: low), but rivaroxaban was associated with higher risk of major bleeding (HR = 1.39, 95% CI 1.28–1.50; evidence quality: moderate). Compared with apixaban, a significantly higher risk of major bleeding was observed with rivaroxaban (HR = 1.71, 95% CI 1.51–1.94; evidence quality: low). Apixaban was associated with lower risk of major bleeding, in comparison with dabigatran (HR = 0.80, 95% CI 0.68–0.95; evidence quality: low). No differences in risk of stroke or systemic embolism was observed between rivaroxaban versus apixaban, and apixaban versus dabigatran. In this study, apixaban was found to have the most favorable safety profile amongst the three NOACs. No significant difference was observed in risk of stroke or systemic embolism between the NOACs. Such findings may provide some decision-making support for physicians regarding their choices amongst NOACs in patients with AF.Published versio

Length of hospitalization and mortality for bleeding during treatment with warfarin, dabigatran, or rivaroxaban

<div><p>Background</p><p>Different outcomes among patients hospitalized for bleeding after starting anticoagulation could influence choice of anticoagulant. We compared length of hospitalization, proportion of Intensive Care Unit (ICU) admissions, ICU length of stay, and 30- and 90-day mortality for adults with atrial fibrillation hospitalized for bleeding after starting warfarin, dabigatran, or rivaroxaban.</p><p>Methods</p><p>An US commercial database of 38 million members from 1 November 2010 to 31 March 2014 was used to examine adults with atrial fibrillation hospitalized for bleeding after starting warfarin (2,446), dabigatran (442), or rivaroxaban (256). Outcomes included difference in mean total length of hospitalization, proportion of ICU admissions, mean length of ICU stay, and all-cause 30- and 90-day mortality.</p><p>Results</p><p>Warfarin users were older and had more comorbidities. Multivariable regression modeling with propensity score weighting showed warfarin users were hospitalized 2.0 days longer (95% CI 1.8–2.3; p < 0.001) than dabigatran users and 2.6 days longer (95% CI 2.4–2.9; p < 0.001) than rivaroxaban users. Dabigatran users were hospitalized 0.6 days longer (95% CI 0.2–1.0; p = 0.001) than rivaroxaban users. There were no differences in the proportion of ICU admissions. Among ICU admissions, warfarin users stayed 3.0 days (95% CI 1.9–3.9; p < 0.001) longer than dabigatran users and 2.4 days longer (95% CI 0.9–3.7; p = 0.003) than rivaroxaban users. There was no difference in ICU stay between dabigatran and rivaroxaban users. There were no differences in 30- and 90-day all-cause mortality.</p><p>Conclusions</p><p>Rivaroxaban and dabigatran were associated with shorter hospitalizations; however, there were no differences in 30- and 90-day mortality. These findings suggest bleeding associated with the newer agents is not more dangerous than bleeding associated with warfarin.</p></div

Cohort definition.

<p>Cohort definition.</p

Differences in adjusted mean total length of stay.

<p>Differences in adjusted mean total length of stay.</p

Patient characteristics, unadjusted and propensity score weighted p-values, by treatment group.

<p>Patient characteristics, unadjusted and propensity score weighted p-values, by treatment group.</p

Mean adjusted length of stay, ICU admission, & discontinuation.

<p>Mean adjusted length of stay, ICU admission, & discontinuation.</p