Relationship between renal dysfunction and outcomes in emergency department patients with potential acute coronary syndromes

Objectives To determine whether patients with elevated creatinine who present to the emergency department (ED) with potential acute coronary syndrome (ACS) are at an increased risk of acute myocardial infarction (AMI) or 30-day cardiovascular (CV) events. Methods A secondary analysis of a cohort study of patients presenting to the ED with potential ACS with serum creatinine measurements. Research assistants collected demographics, history, symptoms, hospital course and 30-day follow-up. Outcomes measured were in-hospital AMI and 30-day CV events (death, nonfatal AMI, revascularisation). Prespecified multivariable models included age, gender, race and cardiac risk factors and presenting electrocardiogram (ECG). We used a creatinine cut-off point of 132.6 mmol/l. Data are presented as OR and 95% CI. Results 3451 patients were enrolled (age, 52.9 +/- 13.2; 55% female patients; 64% black patients). There were 120 AMI during initial visit and 232 patients had 30-day CV events (43 deaths, 128 AMI, 120 revascularisations). Creatinine values were normal in 3086 (89.4%) and abnormal in 365 (10.5%) patients. In multivariable models the adjusted OR (95% CI) for the association between abnormal creatinine and AMI was 1.43 (0.88 to 2.30) and 30-day CV events was 1.57 (1.10 to 2.25). The odds of 30-day CV events were increased for patients who were older, male subjects, white, had hyperlipidaemia, hypertension or a history of CAD, or presented with an abnormal ECG. Conclusion In patients with potential ACS in the ED, renal dysfunction predicts a higher likelihood of 30-day CV events, but not an independent predictor after controlling for other risk factors. It appears to be a marker of other CV risks.