Impact of thrombus aspiration in patients with ST-elevation versus non-ST-elevation acute coronary syndrome: a report from a multicentre Japanese PCI registry

A reduction in coronary flow due to thrombus formation is observed in patients with acute coronary syndrome (ACS) as well as in those with ST-segment elevation myocardial infarction (STEMI) and non-STEMI/unstable angina (NSTEMI/UA). Various pharmacological and device-based strategies have been proposed for the direct intervention on this thrombus formation, among which is manual thrombus aspiration (TA). TA is considered to be a simple, safe, and effective procedure for preventing microvascular obstruction and improving short-term patient prognosis. The clinically effective application of TA during primary percutaneous coronary intervention (PCI) in patients presenting with STEMI – while theoretically plausible – remains a controversial topic, despite a number of randomised clinical trials and meta-analyses published in the literature.

Thrombus formation is the prevailing cause of NSTEMI/UA and accounts for 50-60% of cases of patients presenting with ACS. The risks associated with NSTEMI/UA are known to be similar to those of STEMI. In the clinical setting, NSTEMI/UA patients frequently undergo TA to reduce the risk of distal embolisation, particularly when an angiographically proven intracoronary thrombus is present. However, clinical studies investigating the application and effectiveness of TA in the context of NSTEMI/UA remain sparse.