Albuminuria and cardiovascular events in patients with acute coronary syndromes: Results from the TRACER trial

Background Albuminuria is associated with cardiovascular (CV) outcomes. We evaluated albuminuria, alone and in combination with estimated glomerular filtration rate (EGFR), as a predictor of mortality and CV morbidity in 12,944 patients with non-ST-segment elevation acute coronary syndromes. Methods Baseline serum creatinine and urinary dipsticks were obtained, with albuminuria stratified into no/trace albuminuria, microalbuminuria (≥30 but <300 mg/dL), or macroalbuminuria (≥300 mg/dL). Kaplan-Meier rates and proportional Cox hazards models of CV death, overall mortality, CV death or myocardial infarction (MI), and bleeding were calculated. Incidence of acute kidney injury, identified by adverse event reporting and creatinine increase (absolute ≥0.3 mg/dL or relative ≥50%), was descriptively reported. Results Both dipstick albuminuria and creatinine values were available in 9473 patients (73.2%). More patients with macroalbuminuria, versus no/trace albuminuria, had diabetes (66% vs 27%) or hypertension (86% vs 68%). Rates for CV death and overall mortality per strata were 3.1% and 4.8% (no/trace albuminuria); 5.8% and 9.0% (microalbuminuria); and 7.7% and 12.6% (macroalbuminuria) at 2 years of follow-up. Corresponding rates for CV death or MI were 12.2%, 16.9%, and 23.5%, respectively. Observed acute kidney injury rates were 0.6%, 1.2%, and 2.9% (n = 79), respectively. Adjusted HRs for macroalbuminuria on CV mortality were 1.65 (95% CI 1.15-2.37), and after adjustment with EGFR, 1.37 (95% CI 0.93-2.01). Corresponding HRs for overall mortality were 1.82 (95% CI 1.37-2.42) and 1.47 (95% CI 1.08-1.98). Conclusions High-risk patients with non-ST-segment elevation acute coronary syndromes and albuminuria have increased morbidity and increased overall mortality independent of EGFR.