Objectives: The authors sought to validate a clinical decision rule that young adult (younger than 40 years) chest pain patients without known cardiac disease who had either no cardiac risk factors and/or a normal electrocardiogram (ECG) are at low risk (<1%) for acute coronary syndromes (ACS) and 30-day adverse cardiovascular (CV) events.
Methods: A prospective cohort study of patients 24-39 years old who received an ECG for chest pain from July 1999 to March 2002 were included. Cocaine users were excluded. Data collection was structured at presentation, hospital course was followed daily, and 30-day follow-up was obtained by telephone. The main outcome was 30-day adverse CV events (death, acute myocardial infarction, percutaneous intervention, and coronary artery bypass graft). Descriptive statistics were used.
Results: Of 4,492 visits for chest pain, 1,023 met criteria. Patients were most often female (61%) and African American (73%). Ninety-eight percent were available for 30-day follow-up. The overall risks of ACS and 30-day adverse CV events were 5.4% and 2.2%, respectively, in our entire cohort. For patients with no cardiac history and no cardiac risk factors, the risk of ACS and 30-day adverse CV events was 1.8%. The risk in patients with no cardiac history and a normal ECG was 1.3%. Patients with no cardiac history, no cardiac risk factors, and a normal ECG had a risk of 1.0%. A modified clinical decision rule found that in young adult patients without a known cardiac history, either no classic cardiac risk factors or a normal ECG, and initially normal cardiac marker studies, the risk of ACS was also extremely low (0.14%) and there were no adverse CV events at 30-day follow-up (95% confidence interval = 0.1% to 0.2%).
Conclusions: A modified clinical decision rule described a group of patients with a 0.14% risk of ACS that was free from 30-day adverse CV events.