Mahmoodi BK et al. (2008) High absolute risks and predictors of venous and arterial thromboembolic events in patients with nephrotic syndrome: results from a large retrospective cohort study. Circulation 117: 224–230

Data from a number of studies have indicated that patients with nephrotic syndrome (NS) are at an increased risk of thromboembolic events, but the absolute risks of venous thromboembolism (VTE) or arterial thromboembolism (ATE) in this patient population are unknown. To address this lack of information, Mahmoodi et al. assessed the incidences of ATE and VTE in a cohort of 298 patients with NS.

The mean age of the study population was 42 years and 59% of the cohort were male. During a mean follow-up of 10 years, 29 patients had at least one episode of VTE and 43 patients had at least one episode of ATE. The resulting annual incidence rates for VTE and ATE were 1.02% and 1.48%, respectively. However, the incidences of VTE and ATE within 6 months of a diagnosis of NS were considerably higher than these data might indicate—the annual incidences of VTE and ATE on the basis of data obtained in the 6 months following NS diagnosis were 9.85% and 5.52%, respectively. The ratio of proteinuria to serum albumin (a measure of the severity of NS) was significantly associated with the incidence of VTE (hazard ratio 5.6, 95% CI 1.2–26.2; P = 0.03), but neither either parameter alone nor their ratio was predictive of ATE. The incidence of ATE was significantly associated with age, sex, hypertension, diabetes mellitus, smoking and estimated glomerular filtration rate (P ≤0.02 for all).

The authors conclude that patients with NS have high absolute risks of VTE and ATE, particularly in the first 6 months after diagnosis.