Impact of different glycoprotein IIb/IIIa inhibitor infusion routes on infarct size and microvascular obstruction in patients with high thrombotic risk ST elevation myocardial infarction.

OBJECTIVE: Current guidelines recommend the use of glycoprotein IIb/IIIa (GpIIb/IIIa) inhibitors in patients with ST-segment elevation myocardial infarction (STEMI) only as a bail-out therapy. However, drug penetration to the jeopardised area may not be achieved due to impeded blood flow and increased microvascular resistance. Aim of our study is to investigate the impact of distal intracoronary GpIIb/IIIa inhibitor agent infusion in STEMI patients. Primary endpoints were microvascular obstruction (MVO) and infarct size.

METHODS: Patients with STEMI who have high thrombus burden or slow-flow/NR phenomenon and undergoing primary percutaneous coronary intervention (pPCI) were enrolled. Tirofiban was the preferred GpIIb/IIIa inhibitor. Patients were assigned to the systemic intravenous infusion group and intracoronary infusion group in whom bolus dose of tirofiban was distally infused to the infarct related artery. MVO and size of the infarct size were assessed via cardiac MRI.

RESULTS: We prospectively included 75 patients and mean follow-up duration was 383 days. Baseline characteristics were similar between groups except a lower rate of diabetes in distal intracoronary infusion group (p = .006). There was no significant difference in localisation of myocardial infarction, ischaemia duration and preloading of P2Y12 inhibitor between groups. MVO (p = .048) and infarct size (p = .030) were significantly lower in distal intracoronary infusion group.

CONCLUSIONS: Cardiac MRI based assessment revealed that intracoronary administration of GpIIb/IIIa inhibitors distal to the culprit lesion was associated with reduced MVO and infarct size in high thrombotic risk STEMI patients undergoing pPCI.