Abstract 343: Chest Pain Patients at Low Risk for Acute Coronary Syndrome: 30 Day Implications of 25–50% Diameter Coronary Stenosis With Cardiac Computed Tomography
Background: In patients presenting emergently with chest pain, the short-term implications of non-obstructive coronary stenosis reported as 25–50% diameter reduction with cardiac CT angiography (CCTA) are unclear.
Hypothesis: Low risk patients with acute chest pain and found to have 25–50% stenosis on CCTA will have less than a 2% incidence of acute coronary syndrome (ACS) over 30-days.
Methods: A cohort of patients (n=1247) presenting with low-risk chest pain and participating in the CCTA arms of clinical pathways at two centers were used to identify the subgroup of patients prospectively reported to have a 25–50% maximal diameter stenosis at CCTA. Patients were followed through 30 days by telephone and/or record review to determine the occurrence of ACS. ACS included myocardial infarction (MI), coronary revascularization, unstable angina, and cardiovascular death. The observed rate of ACS was compared to a 2% threshold for additional cardiac testing.
Results: Of the chest pain patients with CCTA, 199 of 1247 (16%) had maximal 25–50% stenosis and were included in this analysis. Included patients had a mean age of 50.5 years, most had a TIMI risk score of 0 (52%) or 1 (38%), 68% had at least 2 serial cardiac markers performed and 36% had stress testing or cardiac catheterization. ACS within 30 days occurred in 1/199 (0.5%, 95% CI 0%–2.8%) participants due to MI detected by positive serial cardiac biomarkers obtained during the index hospitalization. No patients experienced cardiovascular death or required revascularization.
Conclusions: The 30-day ACS rate in low-risk chest pain patients with 25–50% stenosis on CCTA was very low (0.5%) and no CVD deaths or revascularization occurred. This provides supporting evidence that additional testing beyond cardiac biomarkers in the acute setting to exclude ACS is not routinely indicated.