Thrombus aspiration in acute myocardial infarction: Rationale and indication

Abstract

Reperfusion of myocardial tissue is the main goal of primary percutaneous coronary intervention (PPCI) with stent implantation in the treatment of acute ST-segment elevation myocardial infarction (STEMI). Although PPCI has contributed to a dramatic reduction in cardiovascular mortality over three decades, normal myocardial perfusion is not restored in approximately one-third of these patients. Several mechanisms may contribute to myocardial reperfusion failure, in particular distal embolization of the thrombus and plaque fragments. In fact, this is a possible complication during PPCI, resulting in microvascular obstruction and no-reflow phenomenon. The presence of a visible thrombus at the time of PPCI in patients with STEMI is associated with poor procedural and clinical outcomes. Aspiration thrombectomy during PPCI has been proposed to prevent embolization in order to improve these outcomes. In fact, the most recent guidelines suggest the routine use of manual aspiration thrombectomy during PPCI (class IIa) to reduce the risk of distal embolization. Even though numerous international studies have been reported, there are conflicting results on the clinical impact of aspiration thrombectomy during PPCI. In particular, data on long-term clinical outcomes are still inconsistent. In this review, we have carefully analyzed literature data on thrombectomy during PPCI, taking into account the most recent studies and meta-analyses.

Keywords: Thrombus aspiration, Thrombectomy, Myocardial reperfusion, Myocardial infarction, No-reflow

Core tip: Distal coronary embolization occurs predominantly at the time of the initial balloon or stent inflation, so thrombus burden reduction by thrombectomy devices before percutaneous coronary intervention may decrease the dangerous phenomenon of no-reflow. Manual aspiration catheters are the most commonly used devices. Several randomized trials have demonstrated the efficacy and safety of pretreatment with manual thrombectomy during primary percutaneous coronary intervention. There are some unanswered questions about thrombus aspiration, including whether there is truly a mortality benefit, which subgroups may or may not benefit from aspiration, and whether patients with a large thrombus burden are better treated with mechanical thrombectomy.