Efficacy and safety of direct oral anticoagulants with and without Aspirin: A systematic review and Meta-analysis

Clinical Characteristics, Patterns of Use, and incidence of Adverse Events in Patients With Nonvalvular Atrial Fibrillation Treated With Oral Anticoagulants in Colombia

Purpose

The aim was to analyze the characteristics, treatment patterns, and clinical outcomes of Colombian patients with non-valvular atrial fibrillation (NVAF) under treatment with oral anticoagulants (OAs).

Patients and Methods

Retrospective cohort in patients with NVAF identified from a drug dispensing database, aged ≥18 years, with first prescription of an OA (index) between January/2013 and June/2018, and a follow-up until June/2019. Data from the clinical history, pharmacological variables, and outcomes were searched. International Classification of Diseases-10 codes were used to identify the patient sample and outcomes. Patients were followed until a general composite outcome of effectiveness (thrombotic events), bleeding/safety or persistence (switch/discontinuation of anticoagulant) events. Descriptive and multivariate analyzes (Cox regressions comparing warfarin and direct oral anticoagulants-DOACs) were carried out.

Results

A total of 2076 patients with NVAF were included. The 57.0% of patients were women and the mean age was 73.3±10.4 years. Patients were followed for a mean of 2.3±1.6 years. 8.7% received warfarin before the index date. The most frequent OA was rivaroxaban (n=950; 45.8%), followed by warfarin (n=459; 22.1%) and apixaban (n=405; 19.5%). Hypertension was present in 87.5% and diabetes mellitus in 22.6%. The mean CHA₂DS₂-VASc Score was 3.6±1.5. The 71.0% (n=326/459) of the warfarin patients presented the general composite outcome, and 24.6% of those with DOACs (n=397/1617). The main effectiveness and safety outcomes were stroke (3.1%) and gastrointestinal bleeding (2.0%) respectively. There were no significant differences between patients with warfarin and DOACs regarding thrombotic events (HR: 1.28; 95% CI: 0.68-2.42), but warfarin was associated with higher bleeding/safety events (HR: 4.29; 95% CI: 2.82-6.52) and persistence events (HR: 4.51; 95% CI: 3.81 -5.33).

Conclusion

The patients with NVAF in this study were mainly older adults with multiple comorbidities. Compared to warfarin, DOACs were found to be equally effective, but safer and had a lower probability of discontinuation or switch.

Direct Oral Anticoagulants as the First Choice of Anticoagulation for Patients with Peripheral Artery Disease to Prevent Adverse Vascular Events: A Systematic Review and Meta-Analysis

The best method of anticoagulation for patients with peripheral artery disease (PAD) is still a topic of interest for physicians. We conducted a meta-analysis to compare the effects of direct oral anticoagulants (DOACs) with those of vitamin-K-antagonist (VKA) anticoagulants in patients with peripheral artery disease. Five databases (Medline (via PubMed), EMBASE, Scopus, Web of Science, and CENTRAL) were searched systematically for studies comparing the effects of the two types of anticoagulants in patients with PAD, with an emphasis on lower-limb outcomes, cardiovascular events, and mortality. In PAD patients with concomitant non-valvular atrial fibrillation (NVAF), the use of DOACs significantly reduced the risk of major adverse limb events (HR = 0.58, 95% CI, 0.39-0.86, p < 0.01), stroke/systemic embolism (HR 0.76; 95% CI 0.61-0.95; p < 0.01), and all-cause mortality (HR 0.78; 95% CI 0.66-0.92; p < 0.01) compared with warfarin, but showed similar risks of MI (HR = 0.81, 95% CI, 0.59-1.11, p = 0.2) and cardiovascular mortality (HR = 0.77, 95% CI, 0.58-1.02, p = 0.07). Rivaroxaban at higher doses significantly increased the risk of major bleeding (HR = 1.16, 95% CI, 1.07-1.25, p < 0.01). We found no significant difference in terms of revascularization (OR = 1.49, 95% CI, 0.79-2.79, p = 0.14) in PAD patients in whom a poor distal runoff was the reason for the anticoagulation. DOACs have lower rates of major limb events, stroke, and mortality than VKAs in PAD patients with atrial fibrillation. Rivaroxaban at higher doses increased the risk of major bleeding compared with other DOAC drugs. More high-quality studies are needed to determine the most appropriate anticoagulation regimen for patients with lower-limb atherosclerosis.