Background
An increased frequency of venous thromboembolism (VTE) has been shown among patients with reduced kidney function as measured by a decreased estimated glomerular filtration rate (eGFR). However, current practices with respect to VTE prevention and management in patients with a reduced eGFR in general population settings remain uncertain.
Study Design
Observational study.
Setting & Participants
Community investigation of 1,509 metropolitan Worcester (Massachusetts) residents with validated VTE during 1999, 2001, and 2003 with further follow-up for up to 3 years.
Predictor
VTE patients further classified according to their eGFR on presentation: < 30, 30-59, 60-89, or ≥ 90 ml/min/1.73m2 (reference group).
Outcomes
Recurrent VTE, major bleeding episodes, and all-cause mortality.
Measurements
Demographic and clinical characteristics, treatment practices, and study outcomes were extracted from patients’ hospital and outpatient medical records; eGFR was estimated using the Chronic Kidney Disease Epidemiology equation.
Results
VTE patients with eGFR < 30 ml/min/1.73m2 were at an increased risk for recurrent VTE (HR, 1.83; 95% CI, 1.03-3.25), major bleeding episodes (HR, 2.30; 95% CI, 1.28-4.16) and all-cause mortality (HR, 1.70; 95% CI, 1.12-2.57) over 3-year follow-up. Patients with reduced eGFR also presented with more co-morbidities and were less likely to be discharged on any form of anticoagulant therapy (72.6%, 81.0%, 82.1%, and 87.3% for eGFR < 30, 30-59, 60-89, and ≥ 90 mL/min/1.73m2, respectively; p<0.001).
Limitations
Reduced eGFR status is presumed based on creatinine values on clinical presentation. The impact of drug dosage, timing, type of anticoagulant therapy, and medication adherence on study outcomes could not be evaluated.
Conclusions
Severe reductions in eGFR are associated with an increased risk of long-term recurrent VTE, bleeding, and total mortality in patients with VTE. A greater frequency of serious co-morbidities, difficulties implementing available management strategies, and suboptimal VTE prophylaxis during hospital admissions likely contributed to our findings.
