Thrombus aspiration in STEMI revisited: impact on coronary microcirculation?

Abstract

In this issue of Open Heart , Hoole et al 1 present the IMPACT trial. The authors investigate the effect of thrombus aspiration (TA) on changes in microvascular function during primary percutaneous coronary intervention (PPCI) for ST elevation myocardial infarction (STEMI). However, no difference between the TA group and the control group receiving balloon angioplasty first line could be verified. This is a timely topic indeed, since the impact of TA on coronary microcirculation was an important rationale to suggest prognostic benefits in patients with STEMI in the past. Early data from smaller and medium-sized randomised controlled trials (RCT) fuelled substantial enthusiasm about the concept of coronary thrombectomy with a view to reduce the thrombus burden, and avoid distal embolisation and consecutive ‘no reflow’ in PPCI.2 ,3 Of note, ‘no reflow’ following PPCI has been observed frequently in this patient cohort.4 This phenomenon has been closely associated with microvascular obstruction and increased myocardial infarct size, with worse adverse clinical outcome.5 Similarly, dislodged debris from the culprit lesion, consisting of conglomerates of platelets and neutrophil granulocytes, may congest the microvasculature and deteriorate the ‘no reflow’.6 This is also a feature of the reperfusion injury (RI), which occurs after restoration of blood flow in the infarcted vessel.6 Notably, this RI has been estimated to account for up to 50% of the final infarct size, and efforts to mitigate the RI and ‘no reflow’ appear therefore as an appealing therapeutic approach. …