Sonothrombolysis in Patients With ST-Elevation Myocardial Infarction With Electrocardiographic No-Reflow After Percutaneous Coronary Intervention: A Randomized Controlled Trial

Abstract

Approximately 50% of patients with ST elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) experience microvascular no-reflow. Pre- and post-PCI sonothrombolysis has been shown to decrease infarct size and improve left ventricular (LV) systolic function in STEMI patients receiving urgent PCI. The aim of this study was to investigate whether post-PCI sonothrombolysis alone in STEMI patients with persistent ST elevation could reduce no-reflow and infarct size. Patients with STEMI with symptoms <12hours who had persistent ST elevation (≤70% ST resolution) after primary PCI were randomized to sonothrombolysis or control. The primary end point was summed (Σ) ST elevation 60minutes after study intervention. Secondary end points included infarct size, myocardial perfusion score, LV ejection fraction on cardiovascular magnetic resonance imaging at 2months follow-up, and clinical outcome at 6-month follow-up. Sixty-seven STEMI patients with persistent ST elevation after PCI were randomized (49 left anterior descending, 18 right coronary/left circumflex artery). No difference was observed in Σ ST elevation 60minutes after study intervention (mean difference, 0.6mm; 95% CI, -1.1 to 2.2, P=.50). Complete ST resolution occurred in 14 (40%) of patients treated with sonothrombolysis compared to 6 (19%) of controls (P=.16). Myocardial perfusion score index (1.5±0.3 vs 1.5±0.3, P=.93), infarct size (18.0%±10% vs 16.8%±11%; P=.29) and LV ejection fraction on cardiovascular magnetic resonance (46%±8% vs 47%±11% in the control group; P=.86) were comparable. Incidence of all-cause death, acute coronary syndrome, and hospital admission for heart failure at 6-month follow-up was similar between the groups (sonothrombolysis, 2; control, 5). In STEMI patients with persistent ST elevation after PCI, post-PCI sonothrombolysis did not result in more ST resolution or smaller infarct size compared to control subjects. The incidence of the combined clinical end points was remarkably low in this high-risk patient population.