Net clinical benefit of rivaroxaban compared with warfarin in atrial fibrillation: Results from ROCKET AF

Quantitative Benefit-Risk Evaluation of Rivaroxaban in Patients After Peripheral Arterial Revascularization: The VOYAGER PAD Trial

BACKGROUND

The VOYAGER PAD (Efficacy and Safety of Rivaroxaban in Reducing the Risk of Major Thrombotic Vascular Events in Subjects With Symptomatic Peripheral Artery Disease Undergoing Peripheral Revascularization Procedures of the Lower Extremities) trial compared rivaroxaban (2.5 mg twice a day) plus aspirin with aspirin alone in patients with symptomatic peripheral artery disease requiring endovascular or surgical limb revascularization, with 50% receiving clopidogrel background therapy. The New Drug Indication application includes benefit-risk assessments using clinical judgment to balance benefits against risks. During its review, the US Food and Drug Administration requested additional quantitative benefit-risk analyses with formal weighting approaches.

METHODS AND RESULTS

Benefits and risks were assessed using rate differences between treatment groups (unweighted analysis). To account for clinical importance of the end points, a multi-criteria decision analysis was conducted using health state utility values as weights. Monte Carlo simulations incorporated statistical uncertainties of the event rates and utility weights. Intent-to-treat and on-treatment analyses were conducted. For unweighted intent-to-treat analyses, rivaroxaban plus aspirin would result in 120 (95% CI, -208 to -32) fewer events of the primary composite end point (per 10 000 patient-years) compared with aspirin alone. Rivaroxaban caused an excess of 40 (95% CI, 8-72) Thrombolysis in Myocardial Infarction major bleeding events, which was largely driven by nonfatal, nonintracranial hemorrhage Thrombolysis in Myocardial Infarction major bleeding events. For weighted analyses, rivaroxaban resulted in the utility equivalent of 13.7 (95% CI, -85.3 to 52.6) and 68.1 (95% CI, 7.9-135.7) fewer deaths per 10 000 patient-years (intent-to-treat and on-treatment, respectively), corresponding to probabilities of 64.4% and 98.7%, respectively, that benefits outweigh risks favoring rivaroxaban per Monte Carlo simulation.

CONCLUSIONS

These analyses show a favorable benefit-risk profile of rivaroxaban therapy in the VOYAGER PAD trial, with findings generally consistent between the unweighted and weighted approaches.

The importance of assessing the safe and effective use of oral anticoagulants in older adults

See the Reply by Semla and Steinman in this issue.

Non-embolic outcomes in patients with cardiovascular disease and atrial fibrillation treated with rivaroxaban

Aim: It is not well known how comorbidities may change the prognosis of atrial fibrillation (AF) patients. This study was aimed to analyze the impact of cardiovascular disease on this population. Materials & methods: EMIR was a multicenter, prospective study, including 1433 AF patients taking rivaroxaban for ≥6 months. Data were analyzed according to the presence of vascular disease. Results: Coronary artery disease was detected in 16.4%, peripheral artery disease/aortic plaque in 6.7%, vascular disease in 28.3%. Patients with coronary artery disease had higher rates (per 100 patient-years) of major adverse cardiovascular events (2.98 vs 0.71; p < 0.001) and cardiovascular death (1.79 vs 0.41; p = 0.004). Those with vascular disease had higher rates of thromboembolic events (1.47 vs 0.44; p = 0.007), major adverse cardiovascular events (2.03 vs 0.70; p = 0.004), and cardiovascular death (1.24 vs 0.39; p = 0.025). Patients with peripheral artery disease/aortic plaque had similar rates. Conclusion: AF patients with vascular disease have a higher risk of non-embolic outcomes.

Benefit-Risk Assessment of Rivaroxaban for Extended Thromboprophylaxis After Hospitalization for Medical Illness

Background Venous thromboembolism (VTE) often occurs after hospitalization in medically ill patients, but the population benefit-risk of extended thromboprophylaxis remains uncertain. Methods and Results The MARINER (Medically Ill Patient Assessment of Rivaroxaban Versus Placebo in Reducing Post-Discharge Venous Thrombo-Embolism Risk) study (NCT02111564) was a randomized double-blind trial that compared thromboprophylaxis with rivaroxaban 10 mg daily versus placebo for 45 days after hospital discharge in medically ill patients with a creatinine clearance ≥50 mL/min. The benefit-risk balance in this population was quantified by calculating the between-treatment rate differences in efficacy and safety end points per 10 000 patients treated. Clinical characteristics of the study population were consistent with a hospitalized medical population at risk for VTE. Treating 10 000 patients with rivaroxaban resulted in 32.5 fewer symptomatic VTE and VTE-related deaths but was associated with 8 additional major bleeding events. The treatment benefit was driven by the prevention of nonfatal symptomatic VTE (26 fewer events). There was no between-treatment difference in the composite of critical site or fatal bleeding. Conclusions Extending thromboprophylaxis with rivaroxaban for 45 days after hospitalization provides a positive benefit-risk balance in medically ill patients at risk for VTE who are not at high risk for bleeding. Registration URL: https://clinicaltrials.gov/; Unique identifier: NCT02111564.

Left Atrial Appendage Occlusion Versus Oral Anticoagulation in Atrial Fibrillation : A Decision Analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is a potential alternative to oral anticoagulants in selected patients with atrial fibrillation (AF). Compared with anticoagulants, LAAO decreases major bleeding risk, but there is uncertainty regarding the risk for ischemic stroke compared with anticoagulation.

OBJECTIVE

To determine the optimal strategy for stroke prevention conditional on a patient's individual risks for ischemic stroke and bleeding.

DESIGN

Decision analysis with a Markov model.

DATA SOURCES

Evidence from the published literature informed model inputs.

TARGET POPULATION

Women and men with nonvalvular AF and without prior stroke.

TIME HORIZON

Lifetime.

PERSPECTIVE

Clinical.

INTERVENTION

LAAO versus warfarin or direct oral anticoagulants (DOACs).

OUTCOME MEASURES

The primary end point was clinical benefit measured in quality-adjusted life-years.

RESULTS OF BASE-CASE ANALYSIS

The baseline risks for stroke and bleeding determined whether LAAO was preferred over anticoagulants in patients with AF. The combined risks favored LAAO for higher bleeding risk, but that benefit became less certain at higher stroke risks. For example, at a HAS-BLED score of 5, LAAO was favored in more than 80% of model simulations for CHA₂DS₂-VASc scores between 2 and 5. The probability of LAAO benefit in QALYs (>80%) at lower bleeding risks (HAS-BLED score of 0 to 1) was limited to patients with lower stroke risks (CHA₂DS₂-VASc score of 2). Because DOACs carry lower bleeding risks than warfarin, the net benefit of LAAO is less certain than that of DOACs.

RESULTS OF SENSITIVITY ANALYSIS

Results were consistent using the ORBIT bleeding score instead of the HAS-BLED score, as well as alternative sources for LAAO clinical effectiveness data.

LIMITATION

Clinical effectiveness data were drawn primarily from studies on the Watchman device.

CONCLUSION

Although LAAO could be an alternative to anticoagulants for stroke prevention in patients with AF and high bleeding risk, the overall benefit from LAAO depends on the combination of stroke and bleeding risks in individual patients. These results suggest the need for a sufficiently low stroke risk for LAAO to be beneficial. The authors believe that these results could improve shared decision making when selecting patients for LAAO.

PRIMARY FUNDING SOURCE

None.

A Structured Literature Review and International Consensus Validation of FORTA Labels of Oral Anticoagulants for Long-Term Treatment of Atrial Fibrillation in Older Patients (OAC-FORTA 2019)

INTRODUCTION

Evidence regarding safety and efficacy of oral anticoagulants for the treatment of atrial fibrillation (AFib) in older adults has been assessed regarding the age appropriateness of oral anticoagulants (OAC) according to the FORTA (Fit fOR The Aged) classification (OAC-FORTA). Three years after its first version (OAC-FORTA 2016), an update was initiated to create OAC-FORTA 2019.

METHODS

A structured review of randomized controlled clinical trials and summaries of individual product characteristics was performed to detect newly emerged evidence on oral anticoagulants in older patients with AFib. This review was used by an interdisciplinary panel of European experts (N = 10) in a Delphi process to label OACs according to FORTA.

RESULTS

A total of 202 records were identified and 11 studies finally included. We found four new trials providing relevant data on efficacy and safety of warfarin, apixaban, dabigatran or rivaroxaban in older patients with AFib. In the majority of studies comparing the non-vitamin-K oral anticoagulants (NOACs) with warfarin, NOACs were superior to warfarin regarding at least one relevant clinical endpoint. The mean consensus coefficient significantly increased from 0.867 (OAC-FORTA 2016) to 0.931 (p < 0.05) and the proposed FORTA classes were confirmed in all cases during the first round (consensus coefficient > 0.8). Warfarin, dabigatran, edoxaban and rivaroxaban were assigned to the FORTA B label, acenocoumarol, fluindione and phenprocoumon were labeled FORTA C and only apixaban was rated as FORTA A.

CONCLUSION

OAC-FORTA 2019 confirms that AFib can be successfully treated with positively labeled antithrombotics at advanced age.

Personalized benefit-risk assessments combining clinical trial and real-world data provide further insights into which patients may benefit most from therapy: Demonstration for a new oral antiplatelet therapy

PURPOSE

Quantitative benefit-risk (B-R) assessments are used to characterize treatment by combining key benefits and risks into a single metric but have historically been done for the "average" patient. Our aim was to conduct an individualized assessment for the oral antiplatelet vorapaxar by combining trial and real-world data to further personalize the treatment profiles.

METHODS

Using linked UK health care databases, we developed risk prediction equations for key ischemic and bleeding events using Cox proportional hazards models. Trial hazard ratios, relative to placebo, were applied to baseline risk estimates to compute expected attributable risks, summed to derive a per-patient net clinical benefit (NCB). High risk subgroups were defined a priori, and Gaussian mixture models (GMM) were fit to characterize the NCB distribution and identify subgroups with similar NCBs.

RESULTS

NCB was consistently positive for all subgroups, likely due to the outcome correlation, and would remain positive with a 12-fold increase in bleeding risk. GMMs identified three distinct NCB subgroups. Compared with the middle/lower NCB subgroups, those with a higher NCB tended to be older, female, and have higher CV disease burden.

CONCLUSIONS

Personalized B-R assessments are feasible and clinically valuable and can be used to better predict who would benefit most from therapy.

Benefits and risks of extended treatment of venous thromboembolism with rivaroxaban or with aspirin

BACKGROUND

Full- or lower-dose anticoagulant therapy or aspirin can be used for extended therapy in patients with venous thromboembolism (VTE), but information on their relative benefit-risk profiles is limited.

METHODS

Data from the EINSTEIN-CHOICE trial were used to compare the benefit-risk profiles of extended treatment with rivaroxaban (20 or 10 mg once daily) and aspirin (100 mg once daily) in VTE patients who had completed 6 to 12 months of anticoagulation therapy. One-year cumulative incidences of recurrent VTE and major bleeding were estimated and benefits and risks were calculated by determining the between group differences in a hypothetical population of 10,000 VTE patients treated for 1 year.

FINDINGS

A total of 1107 patients were treated with 20 mg of rivaroxaban, 1127 with 10 mg of rivaroxaban, and 1131 with aspirin. The cumulative incidences of recurrent VTE in the rivaroxaban 20-mg, rivaroxaban 10-mg and aspirin groups were 1.9%, 1.6%, and 5.0%, respectively, whereas the cumulative incidences of major bleeding were 0.7%, 0.4% and 0.5%, respectively. The incidences of the combined outcome of recurrent VTE and major bleeding were 2.8% and 3.4% lower in the rivaroxaban 20-mg and 10-mg groups than in the aspirin group. For 10,000 patients treated for 1 year, there would be 284 (95% confidence interval [CI] 106 to 462) and 339 (95% CI 165 to 512) fewer events with rivaroxaban 20 mg or 10 mg than with aspirin.

INTERPRETATION

Compared with aspirin, extended anticoagulation with once daily rivaroxaban reduces recurrent VTE with a favourable benefit-risk profile.

FUNDING

Bayer AG.

Drug persistence and outcomes in a cohort of patients with nonvalvular atrial fibrillation treated with rivaroxaban after 2 years of follow-up in clinical practice

Aim: To evaluate medication persistence and outcomes in patients with atrial fibrillation after 2 years of treatment with rivaroxaban in routine practice. Methods: Retrospective study of atrial fibrillation patients in whom rivaroxaban was prescribed during the first quarter of 2014 in the healthcare area of Costa del Sol (Málaga). Results: A total of 111 patients (mean age 74.9 ± 10.9 years; 52.3% men; CHA2DS2-VASc 3.6 ± 1.3; HAS-BLED 1.3 ± 0.6) were included. A total of 96.3 and 90.6% of patients remained on rivaroxaban therapy after 1 and 2 years of treatment, respectively. During this period, stroke, net clinical benefit outcome (thromboembolic events, myocardial infarction, cardiovascular death and major bleeding) and cardiovascular death occurred in 3.6, 5.4 and 1.8% of patients, respectively. Conclusion: In routine practice, medication persistence with rivaroxaban was high. Rates of major cardiac events were low.