Abstract 18094: Supersaturated Oxygen Therapy Benefits Late Presenters With Anterior ST-Segment Elevation Myocardial Infarction

Abstract

Introduction: Patients with late-presentation ST-Segment Elevation Myocardial Infarction (STEMI) are at increased risk of mortality and development of heart failure and have limited therapeutic options besides percutaneous coronary intervention (PCI). Hypothesis: Intracoronary supersaturated oxygen therapy (SSO2) (Zoll / Therox) is approved as an adjunctive therapy to PCI in STEMI patients and may reduce infarct size in patients with less than 6 hours of ischemia. However, in pre-clinical studies, the delivery of SSO2 reduces infarct size even when delivered 24 hours following coronary occlusion. We hypothesized that late-presenting anterior STEMI patients may benefit from SSO2 therapy following PCI. Methods: We studied 12 patients (7M, 5F; 60 ± 9 years) with ongoing anterior STEMIs and prolonged ischemic times (12.2 ± 7.6 hrs). Ten of the 12 patients had an occluded LAD on presentation with TIMI 0 flow and 11 patients had anterior q-waves in at least 2 consecutive leads on the presenting EKG. All patients underwent successful PCI of the LAD with DES followed by 60 minutes of SSO2 therapy delivered through a catheter placed in the left main coronary artery. Cardiac MRI measurement of LV function and infarct size was performed in all patients 1 to 3 days later. Results: Mean infarct size was 32 ± 10 % of LV mass. Baseline left-ventricular ejection fraction (LVEF) measured within 24 hours of PCI was 37.8 ± 10.0 %. LVEF improved to 50.2 ± 11.2 % on follow-up imaging performed at a mean of 2 months following PCI (p < 0.01). To date, all patients remain alive and no patients have been admitted for heart failure. One patient underwent LVAD placement during his baseline hospitalization for persistent cardiac shock and another patient underwent bypass surgery 7 months later after having developed in-stent restenosis and progressive CAD. Conclusions: SSO2 therapy can be safely performed in high-risk STEMI patients with prolonged ischemic times who undergo successful PCI and is associated with a significant recovery of LV function when measured several months later.