Morbid Obesity and Mortality in Patients With VTE

Background The influence of morbid obesity on mortality in patients receiving anticoagulant therapy for VTE has not been consistently evaluated. Methods Data from the RIETE (Registro Informatizado Enfermedad TromboEmbolica) registry were used to compare the mortality risk during anticoagulation in patients with VTE and morbid obesity (BMI ≥ 40 kg/m2) vs those with normal weight (BMI, 18.5-24.9 kg/m2). Patients with or without active cancer were analyzed separately. Results By September 2018, there were 1,642 patients with VTE and morbid obesity and 14,848 with normal weight in RIETE. Of these, 245 (5.5%) and 1,397 (11.6%), respectively, had cancer. Median duration of anticoagulant therapy was longer in the morbidly obese patients, with cancer (185 vs 114 days) or without cancer (203 vs 177 days). Among cancer patients, 44 (18.0%) morbidly obese and 1,377 (32.8%) patients with normal weight died during anticoagulation. Among those without cancer, 44 (3.1%) morbidly obese died and 601 (5.6%) with normal weight died. On bivariate analysis, morbid obesity was associated with a lower mortality rate, both in patients with cancer (hazard ratio, 0.34; 95% CI, 0.25-0.45) and in those without cancer (hazard ratio, 0.43; 95% CI, 0.32-0.58). Multivariable analysis confirmed a lower hazard of death in morbidly obese patients with cancer (hazard ratio, 0.68; 95% CI, 0.50-0.94) and without cancer (hazard ratio, 0.67; 95% CI, 0.49-0.96). The risk for VTE recurrences or major bleeding did not differ in patients with or without morbid obesity. Conclusions In patients with VTE, the risk for death during anticoagulation was about one-third lower in morbidly obese patients than in those with normal weight, independently of the presence of cancer.