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.