ABSTRACT
Introduction: Current guidelines for invasive coronary angiography (ICA) in patients presenting with NSTE-ACS outline two treatment pathways: early (within 24 hours [hrs]);or late (>24 hrs). Time of hospital admission is used as the start time, however, we hypothesize that pre-hospital time of symptom onset may be a more optimal starting time. This study was designed to test optimal symptom onset-to-angiography time (OAT) and its association with the presence of coronary occlusion and adverse outcomes. Method(s): Secondary data analysis in NSTE-ACS patients (pre-COVID-19) who underwent ICA. We tested the optimal cutoff point of OAT in classifying coronary occlusion using Youden-index analysis. We tested the association of OAT and in-hospital complication (i.e., myocardial infarction [MI] after admission, unplanned transfer to the cardiac intensive care unit, pulmonary edema, cardiogenic shock, dysrhythmia with intervention) and hospital length of stay [LOS]) using regression models. Result(s): In 163 patients: 124 (76%) had an occluded artery;37 (23%) had an in-hospital complication. Overall, the mean OAT was 26+/-22 hrs (24+/-22 vs. 31+/-21, with and without occluded artery, respectively), and the median LOS was 55 hrs. The Youden-index optimum OAT cutoff point was 13.4 hrs. In the two logistic models, the adjusted OAT was associated with the presence of coronary occlusion (Figure A). OAT, as a continuous variable, was associated with LOS (beta=0.64, 95% CI 0.08-1.21, p=0.025), no other in-hospital complications were significant (Figure B) Conclusion(s): In patients presenting with NSTE-ACS, OAT at both 13.4 and <24 hrs is a significant predictor of the presence of coronary artery occlusion. Every hour of delayed OAT was associated with a prolonged hospital LOS 0.64 hrs (38 min). Symptom onset appears to be an important starting point in determining optimal timing of ICA in patients with NSTE-ACS, but requires further study with a large sample of patients.