Association Between White Blood Cell Counts at Diagnosis and Clinical Outcomes in Venous Thromboembolism - From the COMMAND VTE Registry-2.

Background: White blood cell (WBC) counts were reported to be a risk factor for acute adverse events in patients with venous thromboembolism (VTE). However, there are limited data on VTE patients without active cancer.

Methods and results: The COMMAND VTE Registry-2 was a multicenter study enrolling 5,197 consecutive patients with acute symptomatic VTE. We divided 3,668 patients without active cancer into 4 groups based on WBC count quartiles (Q1-Q4) at diagnosis: Q1, ≤5,899 cells/μL; Q2, 5,900-7,599 cells/μL, Q3, 7,600-9,829 cells/μL; and Q4, ≥9,830 cells/μL. Patients in Q4 more often presented with pulmonary embolism (PE) than patients in Q1, Q2, and Q3 (68% vs. 37%, 53%, and 61%, respectively; P<0.001). The proportion of massive PEs among all PEs was higher in Q4 than in Q1, Q2, and Q3 (21% vs. 3.4%, 5.8%, and 11%, respectively; P<0.001). Compared with Q1, Q2, and Q3, patients in Q4 had a higher cumulative 5-year incidence of all-cause death (17.0%, 15.2%, 16.1%, and 22.8%, respectively; P<0.001) and major bleeding (10.9%, 11.0%, 10.3%, and 14.4%, respectively; P=0.002). The higher mortality risk of Q4 relative to Q2 was consistent regardless of the presentations of VTEs.

Conclusions: An elevated WBC count on VTE diagnosis was associated with a higher risk of mortality and major bleeding regardless of VTE presentation, suggesting the potential usefulness of WBC counts for further risk stratification.