Risk of venous thromboembolism in patients by albuminuria and estimated GFR

Background — The risk for venous thromboembolism (VTE) is elevated with albuminuria or a low estimated glomerular filtration rate (eGFR). However, the VTE risk due to the combined effects of eGFR and albuminuria are unknown.

Study Design — Population-based cohort study.

Settings and Participants — 694,956 adults in Ontario, Canada, from 2002 to 2012.

Factors — eGFR and albumin-creatinine ratio (ACR).

Outcome — VTE.

Results — 15,180 (2.2%) VTE events occurred during the study period. Both albuminuria and eGFR were independently associated with VTE. The association of albuminuria and VTE differed by level of eGFR (P for ACR × eGFR interaction < 0.001). After considering the competing risk for death, there was a 61% higher rate of VTE in patients with normal eGFRs (eGFRs>90mL/min/1.73m²) and heavy albuminuria (ACR>300mg/g) compared with those with normal eGFRs and no albuminuria (subdistribution HR, 1.61; 95% CI, 1.38-1.89). Among those with reduced kidney function (eGFR, 15-29mL/min/1.73m²), the risk for VTE was only minimally increased, irrespective of albuminuria (subdistribution HRs of 1.23 [95% CI, 1-1.5] and 1.09 [95% CI, 0.82-1.45] for ACR<30 and >300mg/g, respectively).

Limitations — Only single determinations of ACR and eGFR were used. Diagnostic/International Classification of Diseases codes were used to define VTE.

Conclusions — Albuminuria increases the risk for VTE markedly in patients with normal eGFRs compared with those with lower eGFRs.