Influence of obesity on the safety and efficacy of antithrombotic therapy: a systematic review and meta-analysis

Abstract

Abstract Background/Introduction The prevalence of obesity has increased in recent decades and, considering its association with a higher risk of Venous Thromboembolism (VTE) and Acute Coronary Syndromes (ACS), it is necessary to establish an anticoagulation regimen suitable for this group of patients. The obese population is historically underrepresented in clinical trials, so the effect of obesity on the efficacy and safety of antithrombotic treatment is still uncertain. Purpose To evaluate the influence of obesity on the safety and efficacy of antithrombotic therapy in patients with ACS or VTE. Methods This is a systematic review and meta-analysis, using the MEDLINE/PubMed, Scielo, Cochrane, EMBASE and Lilacs databases. Articles characterized as randomized, cohort or case-control studies that compared the occurrence of clinical outcomes (mortality or bleeding) between obese and non-obese patients using parenteral anticoagulants for the treatment of ACS or VTE were selected. To assess the risk of bias, the Cochrane Risk of Bias Tool and the Newcastle-Ottawa Scale were used. Statistical analysis was performed using Revman 5.4 software with relative risk and 95% CI as analytical parameters. Results Six articles, with a total of 40.939 patients, were eligible for this review, being 3 randomized clinical trials and 3 retrospective cohorts. Of the patients, 87.7% had ACS. The mortality rate was 2.6% (95% CI 2.2–3.0%) in obese patients and 3.6% (95% CI 3.3–4.0%) in non-obese patients, while the rate of major bleeding was 6.0% (95% CI 5.6–6.4%) in the obese group and 6.2% (95% CI 5.9–6.5%) in the non-obese group. The incidence of major bleeding was similar between groups with RR: 0.90, 95% CI: 0.77–1.04, p=0.14. The outcome incidence remained comparable when studies were analyzed separately by anticoagulant: enoxaparin (RR: 0.87, 95% CI, 0.70–1.08, p=0.21) or UFH (RR: 0.96, 95% CI, 0.79–1.17, p=0.67). The mortality rate, measured by only 2 studies, was lower in obese patients, with RR: 0.71, 95% CI 0.59–0.87, p=0.0007. Conclusion In patients treated for VTE or ACS, rates of thrombotic complications, death and bleeding were comparable between obese and non-obese patients, regardless of the antithrombotic used. Funding Acknowledgement Type of funding sources: None.