Microvascular Obstruction in Patients With Anterior STEMI Treated With Supersaturated Oxygen.
BACKGROUND: Supersaturated oxygen (SSO2) delivered into the left anterior descending coronary artery after percutaneous coronary intervention (PCI) for anterior ST-segment elevation myocardial infarction (STEMI) has been shown to reduce infarct size, but its effects on microvascular obstruction (MVO) are unknown. The aim of this study was to compare MVO in patients with anterior STEMI treated with SSO2 after successful primary PCI from 2 studies (the optimized SSO2 pilot and IC-HOT) with similar patients from 7 randomized trials who underwent primary PCI without SSO2 treatment. METHODS: A total of 874 patients with anterior STEMI who underwent MVO assessment using cardiac magnetic resonance imaging within 10 days after primary PCI were included, of whom 90 patients (10.3%) were treated with SSO2. The primary end point was the extent of MVO as a continuous measure in a weighted multivariable model. The secondary end point was the presence of MVO. RESULTS: SSO2 therapy was independently associated with a lower extent of MVO compared with no SSO2 therapy (coefficient, -1.35; 95% CI, -2.58 to -0.11; P = .03). SSO2 therapy was also associated with a borderline lower risk of any MVO (adjusted odds ratio, 0.56; 95% CI, 0.31-1.00; P = .051). CONCLUSIONS: In the present individual patient data pooled analysis from 9 studies, SSO2 therapy was associated with less MVO after successful primary PCI for anterior STEMI.
