Renal Impairment, Recurrent Venous Thromboembolism and Bleeding in Cancer Patients with Acute Venous Thromboembolism-Analysis of the CATCH Study.

Objective: This article assesses the impact of renal impairment (RI) on the efficacy and safety of anticoagulation in patients with cancer-associated thrombosis from the Comparison of Acute Treatments in Cancer Hemostasis (CATCH) study (NCT01130025).

Materials And Methods: Renal function was assessed using the Modification of Diet in Renal Disease equation in patients with cancer-associated thrombosis who received either tinzaparin (175 IU/kg) once daily or warfarin for 6 months, in an open-label, randomized, multi-centre trial with blinded adjudication of outcomes. Associations between baseline RI (glomerular filtration rate [GFR] <60 mL/min/1.73m) and recurrent symptomatic or incidental venous thromboembolism (VTE), clinically relevant bleeding (CRB), major bleeding and death were assessed using Fisher's exact test.

Results: Baseline-centralized GFR data were available for 864 patients (96% of study population). RI was found in 131 patients (15%;  = 69 tinzaparin). Recurrent VTE occurred in 14% of patients with and 8% of patients without RI (relative risk [RR] 1.74; 95% confidence interval [CI] 1.06, 2.85), CRB in 19% and 14%, respectively (RR 1.33; 95% CI 0.90, 1.98), major bleeding in 6.1% and 2.0%, respectively (RR 2.98; 95% CI 1.29, 6.90) and mortality rate was 40% and 34%, respectively (RR 1.20; 95% CI 0.94, 1.53). Patients with RI on tinzaparin showed no difference in recurrent VTE, CRB, major bleeding or mortality rates versus those on warfarin.

Conclusion: RI in patients with cancer-associated thrombosis on anticoagulation was associated with a statistically significant increase in recurrent VTE and major bleeding, but no significant increase in CRB or mortality. No differences were observed between long-term tinzaparin therapy and warfarin.