"Optimized" delivery of intracoronary supersaturated oxygen in acute anterior myocardial infarction: a feasibility and safety study.

OBJECTIVES: We sought to evaluate the feasibility and safety of catheter-based supersaturated oxygen (SSO2 ) delivery via the left main coronary artery (LMCA) following primary percutaneous coronary intervention (PCI).

BACKGROUND: In the multicenter, randomized AMIHOT-II trial, SSO2 delivered into the proximal or mid left anterior descending (LAD) artery via an indwelling intracoronary infusion catheter in patients with acute anterior ST-segment elevation myocardial infarction (STEMI) following primary PCI significantly reduced infarct size but resulted in a numerically higher incidence of safety events.

METHODS: Patients with acute anterior STEMI presenting within 6 hr of symptom onset were enrolled at three centers. Following successful LAD stenting, SSO2 was infused into the LMCA via a diagnostic catheter for 60 min. The primary safety endpoint was the 30-day rate of target vessel failure (composite of death, reinfarction, or target vessel revascularization). Cardiac magnetic resonance imaging (cMRI) was performed at 3-5 and 30 days to assess infarct size.

RESULTS: Twenty patients with acute anterior STEMI were enrolled. The infarct lesion was located in the proximal LAD in 7 cases (35%) and the mid LAD in 13 cases (65%). Following primary PCI, SSO2 was delivered successfully in all cases. Target vessel failure within 30 days occurred in 1 patient (5%). Median [interquartile range] infarct size was 13.7% [5.4-20.6%] at 3-5 days and 9.6% [2.1-14.5%] at 30 days.

CONCLUSIONS: Following primary PCI in acute anterior STEMI, infusion of SSO2 via the LMCA is feasible, and is associated with a favorable early safety and efficacy profile.