Objective: Current risk stratification of patients with acute chest pain but normal initial cardiac enzymes and nondiagnostic ECG is inefficient. We sought to determine whether contrast-enhanced MDCT-based detection of stenosis is feasible and improves early and accurate triage of patients with acute chest pain.
Subjects and methods: We studied 40 patients (53% men; mean age, 57 +/- 13 years) with chest pain who were awaiting hospital admission to rule out an acute coronary syndrome (ACS) despite the absence of diagnostic ECG changes and normal cardiac enzymes on emergency department presentation. Patients underwent contrast-enhanced MDCT before hospital admission. Afterward, patients received standard clinical care. All physicians involved in the patients' care were blinded to the results of MDCT. An expert panel established the presence or absence of ACS based on American Heart Association (AHA) guidelines. The MDCT images were evaluated for the presence of significant coronary artery stenosis (diameter reduction > 50%) and were used to make a triage decision.
Results: All five patients (12.5%) with ACS (one with non-ST elevation myocardial infarction, four with unstable angina pectoris) had at least one significant coronary stenosis on MDCT (sensitivity, 100% [95% CI, 49-100%)]. ACS was ruled out in 35 patients (87.5%). Significant coronary stenosis was excluded in 26 of the 35 patients without ACS by MDCT (specificity, 74% [CI, 75-88%]), potentially saving 70% of unnecessary hospital admissions.
Conclusion: MDCT-based detection of significant coronary stenoses has tremendous potential to decrease the number of unnecessary hospital admissions, without reducing appropriate admission rates, in patients with chest pain who have nondiagnostic ECG results and normal cardiac enzymes. These results are likely to further improve with advances in MDCT technology.