Multimorbidity and Venous Thromboembolism: Epidemiological Evidence, Pathophysiology, Prophylactic and Therapeutic Anticoagulation Efficacy, Safety, and Difficulties. A Review.

Multimorbidity defined as the co-occurrence of two or more chronic comorbidities, is becoming increasingly burdensome and is a big challenge for healthcare systems all over the world. Venous thromboembolism (VTE) is a potentially lethal disease and is the third most common cardiovascular disease. Multimorbidity is closely associated with VTE, and the VTE risk is approximately fourfold higher in individuals with multimorbidity compared to those without. Notable and consistent evidences show a significant association between multimorbidity and VTE. Plausible mechanisms for the observed associations between multimorbidity and VTE have been outlined, including higher prevalence of identified VTE risk factors, organ function and coagulation function disorders, reduced physical activity, older age, low cognitive level of VTE, and complications following the multimorbidity. Worse therapeutic and prophylactic anticoagulation efficacy, and safety are suggested by the studies, and the VTE recurrence and bleeding risk are higher in patients with multimorbidity compared to those without. Management of the therapeutic and prophylactic anticoagulation for VTE in patients with multimorbidity is difficult, and a balanced and detailed evaluation of the risks of VTE and bleeding is needed, and antiplatelet medications, increased doses or alternative direct oral anticoagulants (DOACs), thromboelastography (TEG), and physical activity may be helpful.