Long-term Outcome after CT Angiography in Patients with Possible Acute Coronary Syndrome

Purpose: To assess the long-term outcome and hospital readmission rate associated with a computed tomographic (CT) angiography-guided strategy used to examine patients who present to the emergency department (ED) with symptoms of possible acute coronary syndrome (ACS). Materials and Methods: The study was approved by the institutional review board, and all patients provided written informed consent. A total of 585 consecutive patients (mean age, 58 years +/- 11 [standard deviation]; 58% were male) with ischemic-type chest pain and low to intermediate risk for ACS were evaluated prospectively. Patients underwent coronary CT angiography after single or serial troponin I (TnI) measurement, depending on time of presentation to the ED. Subsequent care was determined with CT angiography findings: Patients without plaque and patients with nonobstructive plaque and at most mild to moderate stenosis (<40% luminal narrowing) were discharged without further investigation. Patients with moderate stenosis (40%-70% narrowing) were discharged and referred for outpatient stress echocardiography. Patients with severe stenosis (>70% narrowing) were admitted. Discharged patients were contacted and their medical records were reviewed to determine rates of death, ACS, revascularization, and hospital admission. By using binomial distribution, Clopper-Pearson confidence intervals (CIs) were calculated for outcome data. Results: Coronary CT angiography findings were as follows: A total of 196 patients (34%) had no coronary plaque or stenosis, 288 (49%) had nonobstructive plaque, 22 (4%) had moderate stenosis, and 79 (13%) had severe stenosis. At median 47.4-month follow-up (range, 24-57 months) of the 506 discharged patients, five (1%; 95% CI: 0.4%, 2.3%) had been readmitted for chest pain; there were no instances of coronary revascularization, ACS, or death (0% for all; 95% CI: 0%, 0.7%). Follow-up was 100% complete. Conclusion: Use of a CT angiography-guided strategy to investigate patients with low to intermediate risk of ACS who present to the ED with chest pain is safe at long-term follow-up, including patients discharged after single TnI measurement. (C)RSNA, 2014.