Evaluation of the benefit of rivaroxaban on VOYAGER PAD primary composite of limb, heart and brain outcomes using the global rank and win ratio methods

Background/Introduction

The VOYAGER PAD trial demonstrated that rivaroxaban 2.5 mg twice daily added to background antiplatelet therapy reduced a composite of irreversible harm events of the heart limb and brain versus placebo in patients with symptomatic peripheral artery disease (PAD) after lower extremity revascularization. The primary analysis was performed as time to first event with equal weighting of components including fatal and non-fatal events.

Purpose

Traditional time to event analyses of composites generally assess outcomes with equal weights. Analyses evaluating outcomes using ranked or weighted methods may provide clinicians a mechanism to interpret results including different weighting and enable shared decision making with patients.

Methods

Exploratory analyses of the primary composite outcome were prespecified prior to trial completion/database lock. Two previously described approaches to evaluate composite outcomes by ranking or weighting were utilized. The first was the global rank method which includes ranking all components of the composite by order of clinical importance (Table 1) with a primary and alternative ranking prespecified. Each patient is assigned a rank with the worse rank for worse outcome and for patients with the same outcome, those occurring earlier assigned the worse rank. Van Elteren test for differences between groups was applied stratified by type of procedure and clopidogrel use consistent with the primary trial analysis. The second was the unmatched win ratio method according to Pocock's rule which ranked CV death higher than non-fatal events and then compared pairs of subjects, one from each treatment group for wins and losses for wins and losses as outlined in Table 1. Finkelstein and Schoenfeld statistics were utilized with confidence intervals provided from bootstrapping.

Results

A total of 6564 patients were randomized and all outcomes through the common study end date were counted. The global rank method using both the primary and alternative method yielded a statistically significant superior effect of rivaroxaban versus placebo (p-value for primary ranking 0.0158, p-value for alternative ranking 0.0155). When using the win-ratio approach, there were more wins for rivaroxaban (14.8%) than placebo (12.8%) with 72.4% of patients having no primary component events (Figure 1). The overall win ratio was 1.16 95% CI (1.03–1.30) in favor of rivaroxaban with p=0.0167.

Conclusion(s)

Rivaroxaban significantly reduces acute limb ischemia, amputation, MI, ischemic stroke or CV death in PAD after lower extremity revascularization. Exploratory analyses of this efficacy composite show consistent superiority either when considered as a ranked hierarchy of outcomes with CV death as the worst or whether considering a win-ratio approach ranking CV death as worse followed by non-fatal events. These data support the robustness of the primary trial results when considering ranking of the composite components.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer

Efficacy and safety of low-dose rivaroxaban on top of aspirin in patients with polypharmacy and multimorbidity: an analysis from the COMPASS trial

Background

In patients with coronary or peripheral artery disease, intensified antithrombotic therapy with aspirin plus low dose rivaroxaban reduced cardiovascular outcomes compared with aspirin alone. Polypharmacy and multimorbidity are frequent in patients with vascular disease and are often perceived as barriers to more intensive pharmacotherapy by both patients and physicians.

Purpose

To report cardiovascular outcomes and the efficacy, safety, and net benefit of low dose rivaroxaban plus aspirin in patients with stable vascular disease by the number of concomitant cardiovascular drugs and by the number of comorbidities.

Methods

We reported ischemic events (cardiovascular death, stroke, or MI), major bleeding (ISTH modified criteria), and a prespecified net clinical outcome in participants from the randomised, double-blind COMPASS study by number of cardiovascular medications (0–2, 3, 4, 5–7) and by number of concomitant medical conditions. We compared rates and hazard ratios of patients treated with rivaroxaban plus aspirin vs aspirin alone by category of number of medications and concomitant conditions and tested for interaction between polypharmacy and multimorbidity and antithrombotic regimen.

Results

Although patients with polypharmacy and multimorbidity have a higher risk of cardiovascular events (Figure) those who required many cardiovascular drugs derived the largest absolute reduction in the net clinical outcome when adding rivaroxaban on top of aspirin. The relative efficacy, safety, and net clinical benefit of adding low-dose rivaroxaban to aspirin in patients with stable vascular diseases were not affected by the number of cardiovascular drugs or by the number of comorbidities. Multimorbidity, but not polypharmacy, was related with a higher risk of major bleeding.

Conclusion

Addition of low-dose rivaroxaban conveyed a benefit irrespective of the number of concomitant drugs or comorbid conditions. Multiple comorbidities and/or polypharmacy should not dissuade the addition of low-dose rivaroxaban to aspirin in otherwise eligible patients.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): The COMPASS trial was funded by Bayer AG.

Moxifloxacin for the treatment of patients with complicated intra-abdominal infections (the AIDA Study)

This prospective, randomized, open, international, multicenter study of adults with complicated intra-abdominal infections (cIAI) compared the efficacy and safety of sequential intravenous (i.v.) to oral (p.o.) moxifloxacin 400 mg once daily, with that of i.v. ceftriaxone 2 g once daily, plus metronidazole 500 mg three times daily, followed by p.o. amoxicillin/clavulanate 625 mg three times daily. The primary efficacy variable was clinical cure at test of cure (TOC) (day 28-42 after study entry) in the per protocol (PP) population. Of 595 patients in the study, 511 patients were valid for PP analysis (246 moxifloxacin, 265 ceftriaxone/metronidazole). Sequential moxifloxacin was noninferior to the comparator regimen--clinical cure rates at TOC were 80.9% versus 82.3% (moxifloxacin versus ceftriaxone/metronidazole; 95% CI -8.9, 4.2%). The incidence of adverse events was comparable between the two treatment groups. Therefore, sequential moxifloxacin monotherapy is as effective and safe as combination therapy with i.v. ceftriaxone plus i.v. metronidazole followed by oral amoxicillin/clavulanate for the treatment of cIAI.