Initial experience with hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction: Results of a pilot study utilizing intracoronary aqueous oxygen therapy

Objectives The purpose of this study was to evaluate the feasibility and safety of intracoronary hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction (MI). Background Hyperoxemic therapy with aqueous oxygen (AO) attenuates reperfusion injury and preserves left ventricular (LV) function in experimental models of MI. Methods In a multi-center study of patients with acute MI undergoing primary angioplasty (PTCA), hyperoxemic blood (pO2: 600 to 800 mm Hg) was infused into the infarct-related artery for 60 to 90 min after intervention. The primary end points were clinical, electrical and hemodynamic stability during hyperoxemic reperfusion and in-hospital major adverse cardiac events. Global and regional LV function was evaluated by serial echocardiography after PTCA, after AO infusion, at 24 h and at one and three months. Results Twenty-nine patients were enrolled (mean age: 58.9 ± 12.6 years). Hyperoxemic reperfusion was performed successfully in all cases (mean infusion time: 80.8 ± 18.2 min; mean coronary perfusate pO2: 631 ± 235 mm Hg). There were no adverse events during hyperoxemic reperfusion or the in-hospital period. Compared with baseline, a significant improvement in global wall motion score index was observed at 24 h (1.68 ± 0.24 vs. 1.48 ± 0.24, p < 0.001) with a trend toward an increase in ejection fraction (48.6 ± 7.3% vs. 51.8 ± 6.8%, P = 0.08). Progressive improvement in LV function was observed at one and three months, primarily due to recovery of infarct zone function. Conclusions Intracoronary hyperoxemic reperfusion is safe and well tolerated after primary PTCA. These preliminary data support the need for a randomized controlled trial to determine if hyperoxemic reperfusion enhances myocardial salvage or improves long-term outcome.