Thrombus Aspiration in Patients with ST-Segment Elevation Myocardial Infarction Presenting Late after Symptom Onset

Objectives The aim of this study was to examine whether manual thrombus aspiration reduces microvascular obstruction assessed by cardiac magnetic resonance imaging in patients with ST-segment elevation myocardial infarction (STEMI) presenting late after symptom onset. Background Thrombus aspiration is an established treatment option in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). However, there are only limited data on the efficacy of thrombus aspiration in patients with STEMI presenting ≥12 h after symptom onset. Methods Patients with subacute STEMI presenting ≥12 and ≤48 h after symptom onset were randomized to primary PCI with or without manual thrombus aspiration in a 1:1 ratio. Patients underwent cardiac magnetic resonance imaging 1 to 4 days after randomization. The primary endpoint was the extent of microvascular obstruction. Results A total of 152 patients underwent randomization. The mean time between symptom onset and PCI was 28 ± 12 h. Baseline characteristics were comparable between groups. The majority of patients (60%) showed at least a moderate amount of viable myocardium in the affected region. Extent of microvascular obstruction was not significantly different between patients assigned to thrombus aspiration and the control group (2.5 ± 4.0% vs. 3.1 ± 4.4% of left ventricular mass, p = 0.47). There were also no significant differences in infarct size, myocardial salvage, left ventricular ejection fraction, and angiographic and clinical endpoints between groups. Conclusions In this first randomized trial of thrombectomy in patients with STEMI presenting late after symptom onset, routine thrombus aspiration before PCI failed to show a benefit for markers of reperfusion success. (Effect of Thrombus Aspiration in Patients With Myocardial Infarction Presenting Late After Symptom Onset; NCT01379248)