Evaluation of intracoronary hyperoxemic oxygen therapy in acute anterior myocardial infarction: The IC‐HOT study

Background In the randomized AMIHOT‐II trial, supersaturated oxygen [SSO2] delivered into the left anterior descending (LAD) artery via an indwelling intracoronary infusion catheter following primary percutaneous coronary intervention (PCI) significantly reduced infarct size in patients with anterior ST‐segment elevation myocardial infarction (STEMI) but resulted in a numerically higher incidence of safety events. Objectives The IC‐HOT study evaluated the safety of SSO2 therapy selectively delivered to the left main coronary artery (LMCA) for 60 minutes after PCI in patients with anterior STEMI. Methods SSO2 therapy was administered to the LMCA after stent implantation in 100 patients with anterior STEMI and proximal or mid‐LAD occlusion presenting within 6 hours of symptom onset. The primary endpoint was the 30‐day composite rate of net adverse clinical events (NACE) (death, reinfarction, clinically driven target vessel revascularization, stent thrombosis, severe heart failure, or TIMI major/minor bleeding) compared against an objective performance goal of 10.7%. Cardiac magnetic resonance imaging was performed at 4 and 30 days to assess infarct size. Results SSO2 delivery was successful in 98% of patients. NACE at 30 days occurred 7.1% of patients (meeting the primary safety endpoint of the study); there were no deaths, only one stent thrombosis and one case of severe heart failure. Median [interquartile range] infarct size was 24.1% [14.4%, 31.6%] at 4 days and 19.4% [8.8%, 28.9%] at 30 days. Conclusion Following primary PCI in acute anterior STEMI, infusion of SSO2 via the LMCA was feasible and was associated with a favorable early safety profile.