Comparing U.S. and Canadian treatment patterns on venous thromboembolism outcomes in the GARFIELD-VTE registry

Background: Economically developed countries continue to find that venous thromboembolism (VTE) is a major cause of morbidity and mortality.

Objective: To compare baseline risk profiles and patient workflow patterns between the United States (U.S.) and Canadian management of VTE patients from 2014 to 2017.

Methods: The Global Anticoagulant Registry in the FIELD (GARFIELD-VTE) is a prospective, observational study of 10,679 patients with objectively confirmed VTE, followed for 3 years. In total 1101 patients enrolled in the U.S. and Canada were included in this analysis.

Results: Median age and body mass index were comparable between the U.S. (60.5; 30.2) and Canadian (59.7; 29) patients. A higher percentage of U.S. patients were black (n = 128, 24.1 %; n = 22, 3.9 %) and had a higher VTE-associated risk profile, including immobilization, hospitalization, and recent surgery. U.S. patients had a higher combined DVT and PE primary diagnoses (20.3 %) and were more likely to be treated in hospitals (77.2 %) than Canadians (13.3 %; 48.1 %). Direct oral anticoagulant therapy (DOAC) was nearly two-fold more frequent in Canadian patients (n = 218, 39.2 %) at the end of 3 years in comparison to the U.S. (n = 118, 23.0 %). Adjusted for sex, recent bleed event, heart failure, chronic immobilization, family history of VTE, history of cancer and prior VTE, and renal insufficiency, the risk of all-cause mortality was 51.9 % higher in patients from the U.S. compared to those in Canada after 3 years. Patients from the U.S. also had a higher likelihood of hospitalization, major bleeding, and recurrent VTE after controlling for prior history and comorbid conditions.

Conclusion: Higher rates of adverse VTE-associated outcomes in the U.S. may be attributed to different baseline risk profiles, facility care, and distribution of specialists and their subsequent treatment strategies.

Type of research: Global, multicentre, non-interventional, prospective registry titled Global Anticoagulant Registry in the FIELD - Venous Thromboembolism (GARFIELD-VTE).

Key findings: 531 U.S. and 557 Canadians patients included in study. DOAC use more frequent in Canadian patients after 3 years than U.S. (39.2 % vs. 23.0 %, respectively). Adjusted for sex, recent bleed event, heart failure, chronic immobilization, family history of VTE, history of cancer and prior VTE, and renal insufficiency, all-cause mortality risk remained higher in U.S. patients vs. Canadian patients after 3 years. U.S. patients had higher likelihood of hospitalization, major bleeding, and recurrent VTE.

Take-home message: Higher rates of adverse VTE-associated outcomes in the U.S. may be attributed to different baseline risk profiles, facility care, and composition of specialists and their subsequent treatment strategies.

Table of contents summary: Global, multicentre, non-interventional, prospective registry titled Global Anticoagulant Registry in the FIELD - Venous Thromboembolism (GARFIELD-VTE). Higher rates of adverse VTE-associated outcomes were observed in U.S. patients vs Canadian patients, which may be attributed to different baseline risk profiles, facility care, and distribution of specialists and their subsequent treatment strategies.