Safety Profile Favors Apixaban Over Rivaroxaban in High-Risk Patients with Atrial Fibrillation and Peripheral Artery Disease

Introduction: The Complex Intersection of AF and PAD

The management of patients with non-valvular atrial fibrillation (NVAF) often requires a nuanced approach, particularly when comorbid with peripheral artery disease (PAD). This specific patient population represents a high-risk cohort characterized by a dual burden of thromboembolic risk: the risk of stroke and systemic embolism from the heart, and the risk of major adverse limb events (MALE) from the peripheral vasculature. For years, Direct Oral Anticoagulants (DOACs) have been the cornerstone of therapy for NVAF. However, comparative evidence specifically tailored to those with concurrent PAD has remained relatively sparse, leaving clinicians to extrapolate data from broader trials.

Both rivaroxaban and apixaban are frequently prescribed Factor Xa inhibitors. While their efficacy in the general NVAF population is well-documented, their comparative performance in the AF-PAD population is critical. A recent population-based cohort study by Dari et al., published in the European Heart Journal – Cardiovascular Pharmacotherapy, provides much-needed clarity on this comparison, evaluating whether one agent holds a definitive advantage in terms of effectiveness and safety.

Highlights of the Research

The study provides several key takeaways for clinicians managing the AF-PAD patient profile:

• Effectiveness in preventing major adverse limb events (MALE) and stroke/systemic embolism was comparable between rivaroxaban and apixaban.
• Rivaroxaban was associated with a statistically significant 55% increase in the risk of major bleeding compared to apixaban.
• The findings persist across various major cardiovascular events (MACE), reinforcing apixaban’s role as a potentially safer choice in this specific multi-morbid population.

Study Design and Methodology

To address the clinical question, researchers conducted a robust population-based cohort study using the UK Clinical Practice Research Datalink (CPRD). This database provides a comprehensive look at real-world clinical practice, capturing diverse patient demographics and treatment patterns. The study included patients aged 45 years or older with incident NVAF and a history of PAD who initiated therapy with either rivaroxaban or apixaban between 2013 and 2021.

The cohort consisted of 6,170 new users of rivaroxaban and 9,990 new users of apixaban. The mean age of the participants was approximately 78.5 years, and 44% were female, reflecting a typically elderly and high-risk population seen in daily practice. To minimize the impact of confounding factors—such as age, renal function, and baseline comorbidities—the researchers employed propensity score fine stratification and weighting. This rigorous statistical approach ensures that the comparisons between the two drug groups are as balanced as possible, mimicking the conditions of a randomized controlled trial.

Primary Outcomes and Endpoints

The study focused on three primary areas:

• Effectiveness (Limb): Major adverse limb events (MALE).
• Effectiveness (Systemic): A composite of ischemic stroke, transient ischemic attack (TIA), or systemic embolism (SE).
• Safety: Major bleeding (MB).
• Secondary Outcome: Major adverse cardiovascular events (MACE), including myocardial infarction and cardiovascular death.

Key Findings: Comparable Efficacy, Divergent Safety

The results of the analysis provide a clear distinction between the effectiveness of the two medications and their respective safety profiles. When looking at the primary effectiveness endpoints, the differences between rivaroxaban and apixaban were not statistically significant.

Effectiveness Outcomes

For Major Adverse Limb Events (MALE), the incidence rates were 6.7 per 1,000 person-years for rivaroxaban and 5.6 per 1,000 person-years for apixaban. The adjusted Hazard Ratio (aHR) was 1.20 (95% CI 0.87–1.65). Similarly, the risk for the composite endpoint of stroke, TIA, or systemic embolism showed no significant difference, with an aHR of 1.15 (95% CI 0.97–1.36). The incidence of MACE also remained similar between the two groups (aHR 1.10; 95% CI 0.94–1.28). These findings suggest that both agents are equally capable of managing the thrombotic risks associated with AF and PAD.

The Safety Signal: Major Bleeding

The most striking result of the study was in the safety domain. Major bleeding rates were significantly higher in the rivaroxaban group compared to the apixaban group. Specifically, the incidence of major bleeding was 46.1 per 1,000 person-years for rivaroxaban versus 29.8 per 1,000 person-years for apixaban. This translated to an adjusted Hazard Ratio of 1.55 (95% CI 1.36–1.77). This 55% increased risk of bleeding with rivaroxaban represents a clinically meaningful difference that may influence prescribing decisions, especially in an elderly population already prone to hemorrhagic complications.

Expert Commentary and Clinical Implications

The findings of this study align with broader observations in the DOAC literature, where apixaban has frequently demonstrated a superior safety profile regarding gastrointestinal and major bleeding compared to rivaroxaban. However, seeing this trend replicated specifically in the PAD sub-population is vital. Patients with PAD often have more extensive systemic atherosclerosis and are frequently prescribed concomitant antiplatelet therapy, which further elevates bleeding risks.

Biological Plausibility

The difference in bleeding risk may be attributed to the pharmacokinetic profiles of the two drugs. Rivaroxaban is typically administered once daily, leading to higher peak concentrations (Cmax) compared to the twice-daily dosing of apixaban. These higher peaks may predispose patients to bleeding episodes. Conversely, the twice-daily regimen of apixaban results in more stable plasma concentrations with lower peaks, which may explain its more favorable safety profile in real-world cohorts.

Guideline Context

Current guidelines for NVAF generally recommend DOACs over warfarin, but they do not always specify a preference between individual DOACs. However, for patients with high bleeding risk—a category many PAD patients fall into—this data provides evidence-based support for prioritizing apixaban. It is also important to note that the study reflects “real-world” use, including various dosing levels and patient adherence patterns, which adds to its generalizability.

Study Limitations

As with any observational study, certain limitations must be acknowledged. While propensity score weighting was used, the possibility of residual confounding remains. Factors such as physician preference, subtle differences in patient frailty, or socioeconomic status might not have been fully captured. Furthermore, the study relied on electronic health records, which are subject to coding errors. Nevertheless, the large sample size and the consistency of the results with previous DOAC comparisons lend high credibility to the findings.

Conclusion

For clinicians managing patients with the challenging combination of atrial fibrillation and peripheral artery disease, the choice of anticoagulant is a critical decision. The evidence from this population-based study suggests that while rivaroxaban and apixaban provide equivalent protection against devastating limb and embolic events, apixaban is the safer option. With a 55% lower risk of major bleeding, apixaban offers a more favorable risk-benefit ratio for this vulnerable population. Future research may continue to explore whether these results hold true across different stages of PAD severity, but for now, the data strongly supports apixaban as a preferred therapeutic agent in the AF-PAD landscape.

References

Dari L, Beradid S, Constans J, Pariente A, Renoux C. Effectiveness and safety of rivaroxaban vs. apixaban in patients with atrial fibrillation and peripheral artery disease. Eur Heart J Cardiovasc Pharmacother. 2025 Dec 16;11(8):664-673. doi: 10.1093/ehjcvp/pvaf063. PMID: 40884391.