Pharmacokinetics and Dosing Regimens of Direct Oral Anticoagulants in Morbidly Obese Patients: An Updated Literature Review

Safety and efficacy of direct oral anticoagulants in comparison to warfarin in obese patients with atrial fibrillation: A systematic review and meta-analysis

Background and Aim

Obesity affects nearly 650 million adults worldwide, and the prevalence is steadily rising. This condition has significant adverse effects on cardiovascular health, increasing the risk of hypertension, coronary artery disease, heart failure, and atrial fibrillation (AF). While anticoagulation for obese patients with AF is a well-established therapy for the prevention of thromboembolism, the safety and efficacy of different anticoagulants in this specific population are not well explored. This meta-analysis aimed to compare direct oral anticoagulants (DOAC) to vitamin K antagonists in obese populations with AF.

Methods

The PRISMA guidelines were followed for this meta-analysis, registered in PROSPERO (CRD42023392711). PubMed, PubMed Central, Embase, Cochrane Library, and Scopus databases were searched for relevant articles from inception through January 2023. Two independent authors screened titles and abstracts, followed by a full-text review in Covidence. Data were extracted in Microsoft Excel and analyzed using RevMan v5.4 using odds ratio as an effect measure.

Results

Two thousand two hundred fifty-nine studies were identified from the database search, and 18 were included in the analysis. There were statistically significant reductions in the odds of ischemic and hemorrhagic stroke in the DOAC group compared with the VKA group (OR 0.70, CI 0.66-0.75) and (OR 0.47, CI 0.35-0.62), respectively. In addition, the DOAC group exhibited lower odds of systemic embolism (OR 0.67, CI 0.54-0.83), major bleeding (OR 0.62, CI 0.54-0.72), and composite outcome (OR 0.72, CI 0.63-0.81).

Conclusion

Based on the findings from this meta-analysis, DOACs demonstrate superior safety and efficacy in obese patients with AF compared with VKAs. These results may have significant implications for guiding anticoagulation strategies in this patient population.

Real life results of direct-acting oral anticoagulants recommended-dose in obese vs normal-weight patients with venous thromboembolism

BACKGROUND

There is scarce evidence on the effectiveness and safety of recommended-dose direct acting oral anticoagulants (DOACs) in obese patients with venous thromboembolism (VTE).

MATERIAL AND METHODS

We used the data in the RIETE registry to compare the rates of VTE recurrences and major bleeding during long-term therapy with DOACs at recommended doses in patients with body mass index ≥30 kg/m2 (obese) vs. those with BMI 18.5-24.9 kg/m2 (normal weight). We performed regression models with competing risks for death.

RESULTS

From January 2013 through October 2022, 2885 obese patients and 2676 with normal weight in RIETE received rivaroxaban (n = 3020), apixaban (n = 1754), edoxaban (n = 636) or dabigatran (n = 151). Median age was 63 years and 52 % were female. At baseline, obese patients were more likely to have diabetes (18.6 % vs. 8.4 %), hypertension (51.9 % vs. 31.4 %) or pulmonary embolism (67.7 % vs. 61 %), and less likely to have renal insufficiency (5.3 % vs. 16 %) or anaemia (21.8 % vs. 28 %%). During anticoagulation (median, 147 vs. 101 days), the obese had a similar rate of VTE recurrences (1.71 vs. 2.14 events per 100 patients-years; hazard ratio (HR): 0.81; 95 % CI: 0.49-1.34) or major bleeding (1.45 vs. 1.76 per 100 patients-years; HR: 0.91; 95 % CI: 0.52-1.59) than those with normal weight. These findings persisted after multivariable analysis (recurrent VTE, HR: 0.80; 95 % CI: 0.48-1.32; major bleeding, HR: 1.11; 95 % CI: 0.60-2.07).

CONCLUSION

The use of DOACs at recommended doses in obese patients with VTE was associated with similar rates of VTE recurrences or major bleeding than in patients with normal weight.

Prediction of early neurological deterioration in acute ischemic stroke patients treated with intravenous thrombolysis

A proportion of acute ischemic stroke (AIS) patients suffer from early neurological deterioration (END) within 24 hours following intravenous thrombolysis (IVT), which greatly increases the risk of poor prognosis of these patients. Therefore, we aimed to explore the predictors of early neurological deterioration of ischemic origin (ENDi) in AIS patients after IVT and develop a nomogram prediction model. This study collected 244 AIS patients with post-thrombolysis ENDi as the derivation cohort and 155 patients as the validation cohort. To establish a nomogram prediction model, risk factors were identified by multivariate logistic regression analysis. The results showed that neutrophil to lymphocyte ratio (NLR) (OR 2.616, 95% CI 1.640-4.175, P < 0.001), mean platelet volume (MPV) (OR 3.334, 95% CI 1.351-8.299, P = 0.009), body mass index (BMI) (OR 1.979, 95% CI 1.285-3.048, P = 0.002) and atrial fibrillation (AF) (OR 8.012, 95% CI 1.341-47.873, P = 0.023) were significantly associated with ENDi. The area under the curve of the prediction model constructed from the above four factors was 0.981 (95% CI 0.961-1.000) and the calibration curve was close to the ideal diagonal line. Therefore, this nomogram prediction model exhibited good discrimination and calibration power and might be a reliable and easy-to-use tool to predict post-thrombolysis ENDi in AIS patients.

Safety and efficacy of oral anticoagulants in extreme weights

BACKGROUND

The 2021 International Society on Thrombosis and Haemostasis' (ISTH) recommends standard doses of apixaban and rivaroxaban regardless of high body mass index (BMI) and weight, but had not compare DOACs head-to-head in obesity or address underweight patients.

METHODS

Our aim is to evaluate the safety and efficacy of DOACs in underweight and obese patients compared to warfarin. The primary endpoints include incidence of thromboembolic and bleeding events. Descriptive statistics was used for continuous variables. The Kruskal-Wallis test was used to compare the four-groups for continuous measures and the chi-square test or Fisher's exact test was used to analyze categorical data. The chi-square test or Fisher's exact test, was used for categorical variables, and the Mann-Whitney test (the non-parametric counterpart to the two-sample t-test) for continuous data.

RESULTS

Of 2940 patients receiving anticoagulation for venous thromboembolism (VTE) treatment or atrial fibrillation (AF), 492 met eligibility criteria. Within each group, 248 patients received warfarin, 101 received apixaban, 100 received rivaroxaban and 43 received dabigatran. Patients were characterized in 4 body mass index (BMI) categories, in which 80 were underweight and 412 were obese.

CONCLUSIONS

When each DOAC was compared to warfarin in rates of VTE, apixaban showed statistically significant lower rate of VTE (p = 0.0149). However, no statistical significance was identified in the rate of VTE between DOACs combined vs. warfarin (p = 0.1529). When each DOAC was compared to warfarin, apixaban showed the lowest rate of overall bleeding (p = 0.0194). However, no statistical difference in the rate of bleeding was observed between DOACs combined vs. warfarin (p = 0.3284). Patients with extreme body weights requiring anticoagulation for VTE and AF may safety benefit from DOAC therapy. This evaluation showed apixaban with the lowest rate of VTE and bleeding compared to warfarin, rivaroxaban, and dabigatran. These results provide experience for the clinician to use DOACs, particularly apixaban, in underweight and obese populations.

The Importance of Assessing Drug Pharmacokinetics and Pharmacodynamics in the Obese Population During Drug Development

Obesity remains a US national health crisis and a growing concern worldwide. Concerningly, individuals who are obese are at an increased risk for comorbid diseases that include, but are not limited to, hypertension, diabetes, cardiovascular disease, and cancer. Beyond the risk for developing these conditions, obesity may also impact the pharmacological activity of the therapies being used to treat them and other disease states. The pharmacokinetics (PK), pharmacodynamics (PD), safety, and efficacy of therapies, both currently marketed and under clinical development, may be directly impacted by the physiological alterations that occur secondary to the occurrence of chronic excess body weight. The increased prevalence of this disease should not be ignored. Both private and federal institutions involved in drug research and development should consider, as appropriate, a greater inclusion of individuals who are obese in clinical trials throughout the entirety of drug development, and leverage the available PK, PD, safety, and efficacy data to make more informed dosing recommendations.

Metabolic Syndrome and Atrial Fibrillation: Different Entities or Combined Disorders

Obesity, hypertension, insulin resistance, and dyslipidemia are all clusters of an entity called "Metabolic Syndrome". The global trends of this syndrome's incidence/prevalence continue to increase reciprocally, converting it into a massive epidemic problem in the medical community. Observing the risk factors of atrial fibrillation, a medical condition that is also converted to a scourge, almost all parts of the metabolic syndrome are encountered. In addition, several studies demonstrated a robust correlation between metabolic syndrome and the occurrence of atrial fibrillation. For atrial fibrillation to develop, a combination of the appropriate substrate and a trigger point is necessary. The metabolic syndrome affects the left atrium in a multifactorial way, leading to atrial remodeling, thus providing both the substrate and provoking the trigger needed, which possibly plays a substantial role in the progression of atrial fibrillation. Due to the remodeling, treatment of atrial fibrillation may culminate in pernicious sequelae, such as repeated catheter ablation procedures. A holistic approach of the patient, with simultaneous treatment of both entities, is suggested in order to ensure better outcomes for the patients.