Cardiovascular events and all-cause mortality by albuminuria and decreased glomerular filtration rate in patients with vascular disease

Abstract

Objectives: Albuminuria and decreased estimated glomerular filtration rate (eGFR) are associated with increased cardiovascular risk, but do not necessarily coexist and have different pathophysiological mechanisms. This study aims to evaluate separate and combined effects of decreased eGFR and albuminuria on the occurrence of vascular diseases and mortality in patients with vascular disease.

Design: Prospective cohort study.

Setting: University Medical Center Utrecht, the Netherlands.

Subjects and main outcome measures: 2600 patients with vascular disease were followed for vascular events, vascular and all-cause mortality. Cox regression analysis was used to calculate hazard ratios (HRs) according to eGFR (MDRD) and albuminuria (albumin-to-creatinine ratio >3 mg mmol(-1)).

Results: In this population, 14.0% had albuminuria, 15.6% had eGFR <60 ml min(-1) 1.73 m(-2) and 5.2% had both. Nonalbuminuric decreased eGFR and albuminuria with normal eGFR generated moderately increased risks on all outcomes. eGFR <60 ml min(-1) 1.73 m(-2) without albuminuria mainly influenced the risk of vascular events (HR 1.50; 1.05-2.15) whilst albuminuria with eGFR >or=60 ml min(-1) 1.73 m(-2) principally affected all-cause mortality (HR 1.53; 1.04-2.26). The combination of eGFR <60 ml min(-1) 1.73 m(-2) and albuminuria was associated with an increased risk for vascular events (HR 2.27; 1.54-3.34), vascular mortality (HR 2.22; 1.40-3.52) and all-cause mortality (HR 1.84; 1.25-2.69). Comparable results were found in additional analyses amongst 759 diabetic patients.

Conclusions: The combination of decreased eGFR with albuminuria is associated with the highest risks of vascular events, vascular and all-cause mortality in patients with vascular diseases. To adequately estimate vascular risk associated with impaired renal function, both eGFR and urinary albumin should be considered.