Estimated glomerular filtration rate and albuminuria as predictors of outcomes in patients with high cardiovascular risk: a cohort study.

BACKGROUND: Glomerular filtration rate and albuminuria are risk factors for cardiovascular disease and markers of renal function. OBJECTIVE: To examine the contribution of estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio beyond that of traditional cardiovascular risk factors to classification of patient risk for cardiovascular and renal outcomes. DESIGN: Prospective cohort study that pooled all patients of ONTARGET (ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial) and TRANSCEND (Telmisartan Randomized Assessment Study in Angiotensin-Converting-Enzyme-Inhibitor Intolerant Subjects with Cardiovascular Disease). PATIENTS: 27,620 patients older than 55 years with documented cardiovascular disease, who were followed for a mean of 4.6 years. MEASUREMENTS: Baseline eGFR, urinary albumin-creatinine ratio, and cardiovascular risk factors. Outcomes were all-cause mortality; a composite of cardiovascular death, myocardial infarction, stroke, and hospitalization for heart failure; long-term dialysis; and a composite of long-term dialysis and doubling of serum creatinine level. RESULTS: Lower eGFRs and higher urinary albumin-creatinine ratios were associated with the primary cardiovascular composite outcome (for example, an adjusted hazard ratio of 2.53 [95% CI, 1.61 to 3.99] for an eGFR <30 mL/min per 1.73 m(2) and a very high urinary albumin-creatinine ratio). However, adding information about eGFR and urinary albumin-creatinine ratio to the risk reclassification analyses led to no meaningful decrease in the proportion of patients assigned to the intermediate-risk category (31% without vs. 32% with renal information). In contrast, eGFR and urinary albumin-creatinine ratio were strongly associated with risk for long-term dialysis and greatly improved both model calibration and risk stratification capacity when added to traditional cardiovascular risk factors (65% assigned to intermediate-risk categories without renal information vs. 18% with renal information). LIMITATION: Creatinine levels were not standardized. CONCLUSION: In patients with high vascular risk, eGFR and urinary albumin-creatinine ratio add little to traditional cardiovascular risk factors for stratifying cardiovascular risk but greatly improve risk stratification for renal outcomes. PRIMARY FUNDING SOURCE: Boehringer Ingelheim, Population Health Research Institute, and the European Commission.