Rationale and design of a randomized controlled trial to evaluate thrombus modification efficacy of sustained mechanical aspiration thrombectomy in patients with ST Elevation Myocardial Infarction: The CAPTURE AMI study

Background Distal myocardial perfusion remains impaired in up to half of patients after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI), partly through the distal embolization of thrombus and plaque debris. Reduction of thrombus burden prior to PCI in STEMI has been associated with improved markers of perfusion. However, traditional manual syringe aspiration thrombectomy has demonstrated inconsistent efficacy of thrombus extraction in prior studies. Sustained mechanical aspiration thrombectomy may achieve more reliable coronary thrombus extraction, with promising early results in non-randomized analyses thus far. Objectives CAPTURE AMI (ClinicalTrials.gov; NCT07687576) will test whether sustained mechanical aspiration thrombectomy reduces pre-stent thrombus burden compared with standalone PCI in patients with highly thrombotic STEMI. Methods In this investigator-initiated, single-center randomized controlled trial, 60 patients undergoing primary PCI with TIMI thrombus grade ≥ 4 will be randomized 1:1 to optical coherence tomography (OCT) guided PCI alone, or to sustained mechanical aspiration using the CAT-RX (Penumbra) Aspiration System followed by OCT-guided PCI. The primary endpoint is the absolute change in thrombus burden between two paired pre-PCI OCT runs, measured offline by blinded readers. Exploratory endpoints include pre-PCI thrombus volume, thrombus area and flow area, post-PCI in-stent thromboatheroma and flow volumes, final stent expansion and apposition on OCT, indices of coronary microvascular physiology and major adverse cardiac and cerebrovascular events over 6-month follow-up. Conclusions CAPTURE AMI will provide randomized, imaging- and physiology-based evidence on the thrombus-modifying efficacy of sustained mechanical aspiration thrombectomy in STEMI.