Background: Published data suggest worse outcomes in acute coronary syndrome (ACS) patients and concurrent coronavirus disease 2019 (COVID-19) infection. Mechanisms remain unclear. Objectives: The purpose of this study was to report the demographics, angiographic findings, and in-hospital outcomes of COVID-19 ACS patients and compare these with pre–COVID-19 cohorts. Methods: From March 1, 2020 to July 31, 2020, data from 55 international centers were entered into a prospective, COVID-ACS Registry. Patients were COVID-19 positive (or had a high index of clinical suspicion) and underwent invasive coronary angiography for suspected ACS. Outcomes were in-hospital major cardiovascular events (all-cause mortality, re–myocardial infarction, heart failure, stroke, unplanned revascularization, or stent thrombosis). Results were compared with national pre–COVID-19 databases (MINAP [Myocardial Ischaemia National Audit Project] 2019 and BCIS [British Cardiovascular Intervention Society] 2018 to 2019). Results: In 144 ST-segment elevation myocardial infarction (STEMI) and 121 non–ST-segment elevation acute coronary syndrome (NSTE-ACS) patients, symptom-to-admission times were significantly prolonged (COVID-STEMI vs. BCIS: median 339.0 min vs. 173.0 min; p < 0.001; COVID NSTE-ACS vs. MINAP: 417.0 min vs. 295.0 min; p = 0.012). Mortality in COVID-ACS patients was significantly higher than BCIS/MINAP control subjects in both subgroups (COVID-STEMI: 22.9% vs. 5.7%; p < 0.001; COVID NSTE-ACS: 6.6% vs. 1.2%; p < 0.001), which remained following multivariate propensity analysis adjusting for comorbidities (STEMI subgroup odds ratio: 3.33 [95% confidence interval: 2.04 to 5.42]). Cardiogenic shock occurred in 20.1% of COVID-STEMI patients versus 8.7% of BCIS patients (p < 0.001). Conclusions: In this multicenter international registry, COVID-19–positive ACS patients presented later and had increased in-hospital mortality compared with a pre–COVID-19 ACS population. Excessive rates of and mortality from cardiogenic shock were major contributors to the worse outcomes in COVID-19 positive STEMI patients
