Relationship of mildly increased albuminuria and coronary artery revascularization outcomes in patients with diabetes.

BACKGROUND: The aim of this study was to examine the relationship of albuminuria to cardiovascular disease outcomes in diabetic patients undergoing treatment for stable coronary artery disease. METHODS AND RESULTS: We analyzed data from 2176 participants of the Bypass Angioplasty Revascularization Investigation in type-2 diabetes (BARI-2D) trial, a randomized clinical trial comparing Percutaneous coronary intervention/Coronary artery bypass grafting (PCI/CABG) to medical therapy for people with diabetes. The population was stratified by baseline spot urine albumin-creatinine ratio (uACR) into normal (uACR <10 mg/g), mildly (uACR ≥10 mg/g < 30 mg/g), moderately (uACR ≥30 mg/g < 300 mg/g) and severely increased (uACR ≥300 mg/g) groups, and outcomes compared between groups. Death, myocardial infarction (MI) and/or stroke were experienced by 489 patients at a mean follow-up of 4.3 ± 1.5 years. Compared with normal uACR, mildly increased uACR was associated with a 1.4 times (P = 0.042) increase in all-cause mortality. Additionally, nonwhites with type-II diabetes and stable coronary artery disease who had mildly increased albuminuria had a Hazard ratio (HR) of 3.3 times (P = 0.028) for cardiovascular death, 3.1 times for (P = 0.002) all-cause mortality, and two times for (P = 0.015) MI during follow-up. CONCLUSIONS: Mildly increased albuminuria is a significant predictor of all-cause mortality in those with type-II diabetes mellitus and stable coronary artery disease, as well as for cardiovascular events those who are nonwhites.

Interaction between Albuminuria and Treatment Group Outcomes for Patients with Renal Artery Stenosis: The NITER Study.

PURPOSE: To perform a post-hoc analysis of the Nephropathy Ischemic Therapy (NITER) trial, which enrolled patients with atherosclerotic renal artery stenosis, to evaluate whether medical therapy plus stent placement is superior to medical therapy alone in patients without elevated albuminuria. MATERIALS AND METHODS: Data from 51 patients were analyzed and stratified into 2 cohorts by median urinary albumin (UAlb) levels: cohort 1 ("low albuminuria," UAlb ≤0.04 g/24h) and cohort 2 ("high albuminuria," UAlb >0.04g/24h). Interaction effect between treatment arms and UAlb cohorts was calculated using Cox regression analysis. Survival analysis was followed by test for effect size, power analysis, and construction of a Kaplan-Meier survival table. RESULTS: At study completion, 13 patients had an outcome event: 6 (23%) from cohort 1 and 7 (28%) from cohort 2. Patients in cohort 1 had event-free survival of 83% at 3.9 ± 0.3 years from the primary endpoints of all-cause mortality, dialysis, and cardiovascular events when treated with interventional therapy, compared to 45% when treated with medical therapy alone (P = .501), which showed a 62% treatment effect for stent placement. In cohort 2, event-free survival rates were 64% for medical therapy versus 52% for medical plus interventional therapy (P = .64). Using Cox regression analysis, the interaction effect between treatment arms and UAlb cohorts was not significant (P = .32). The power of the study to detect an interaction effect, if one existed, was only 15%. CONCLUSIONS: Inference cannot be drawn for similar populations because of inadequate sample size, but, in this sample, patients treated with stent placement who had low albuminuria had better outcomes than patients treated with medical therapy alone.