Assessment of Outcomes Among Patients With Venous Thromboembolism With and Without Chronic Kidney Disease

IMPORTANCE: Patients with venous thromboembolism (VTE) and concomitant chronic kidney disease (CKD) have been reported to have a higher risk of thrombosis and major bleeding complications compared with patients without concomitant CKD. The use of anticoagulation therapy is challenging, as many anticoagulant medications are excreted by the kidney. Large-scale data are needed to clarify the impact of CKD for anticoagulant treatment strategies and clinical outcomes of patients with VTE. OBJECTIVE: To compare clinical characteristics, treatment patterns, and 12-month outcomes among patients with VTE and concomitant moderate to severe CKD (stages 3-5) vs patients with VTE and mild to no CKD (stages 1-2) in a contemporary international registry. DESIGN, SETTING, AND PARTICIPANTS: The Global Anticoagulant Registry in the Field–Venous Thromboembolism (GARFIELD-VTE) study is a prospective noninterventional investigation of real-world treatment practices. A total of 10 684 patients from 415 sites in 28 countries were enrolled in the GARFIELD-VTE between May 2014 and January 2017. This cohort study included 8979 patients (6924 patients with mild to no CKD and 2055 patients with moderate to severe CKD) who had objectively confirmed VTE within 30 days before entry in the registry. Chronic kidney disease stages were defined by estimated glomerular filtration rates. Data were extracted from the study database on December 8, 2018, and analyzed between May 1, 2019, and July 30, 2020. EXPOSURE: Moderate to severe CKD vs mild to no CKD. MAIN OUTCOMES AND MEASURES: The primary outcomes were all-cause mortality, recurrent VTE, and major bleeding. Event rates and 95% CIs were calculated and expressed per 100 person-years. Hazard ratios (HRs) were estimated with Cox proportional hazards regression models and adjusted for relevant confounding variables. All-cause mortality was considered a competing risk for other clinical outcomes in the estimation of cumulative incidences. RESULTS: Of the 10 684 patients with objectively confirmed VTE, serum creatinine data were available for 8979 patients (84.0%). Of those, 4432 patients (49.4%) were female and 5912 patients (65.8%) were White; 6924 patients (77.1%; median age, 57 years; interquartile range [IQR], 44-69 years) were classified as having mild to no CKD, and 2055 patients (22.9%; median age, 70 years; IQR, 59-78 years) were classified as having moderate to severe CKD. Calculations using the equation from the Modification of Diet in Renal Disease study indicated that, among the 6924 patients with mild to no CKD, 2991 patients had stage 1 CKD, and 3933 patients had stage 2 CKD; among the 2055 patients with moderate to severe CKD, 1650 patients had stage 3 CKD, 190 patients had stage 4 CKD, and 215 patients had stage 5 CKD. The distribution of VTE presentation was comparable between groups. In total, 1171 patients (57.0%) with moderate to severe CKD and 4079 patients (58.9%) with mild to no CKD presented with deep vein thrombosis alone, 547 patients (26.6%) with moderate to severe CKD and 1723 patients (24.9%) with mild to no CKD presented with pulmonary embolism alone, and 337 patients (16.4%) with moderate to severe CKD and 1122 patients (16.2%) with mild to no CKD presented with both pulmonary embolism and deep vein thrombosis. Compared with patients with mild to no CKD, patients with moderate to severe CKD were more likely to be female (3259 women [47.1%] vs 1173 women [57.1%]) and older than 65 years (2313 patients [33.4%] vs 1278 patients [62.2%]). At baseline, the receipt of parenteral therapy alone was comparable between the 2 groups (355 patients [17.3%] with moderate to severe CKD vs 1253 patients [18.1%] with mild to no CKD). Patients with moderate to severe CKD compared with those with mild to no CKD were less likely to be receiving direct oral anticoagulant therapy, either alone (557 patients [27.1%] vs 2139 patients [30.9%]) or in combination with parenteral therapy (319 patients [15.5%] vs 1239 patients [17.9%]). Patients with moderate to severe CKD had a higher risk of all-cause mortality (adjusted hazard ratio [aHR], 1.44; 95% CI, 1.21-1.73), major bleeding (aHR, 1.40; 95% CI, 1.03-1.90), and recurrent VTE (aHR, 1.40; 95% CI, 1.10-1.77) than patients with mild to no CKD. CONCLUSIONS AND RELEVANCE: In this study of patients with VTE, the presence of moderate to severe CKD was associated with increases in the risk of death, VTE recurrence, and major bleeding compared with the presence of mild to no CKD.