Intravascular ULTRAsound-Guided PCI in Patients With ST-Elevation Myocardial Infarction

Intravascular ULTRAsound-Guided PCI in Patients With ST-Elevation Myocardial Infarction: the ULTRA-STEMI Trial

The main goal of the ULTRA-STEMI trial is to investigate the prognostic impact of IVUS-guided PCI in patients with STEMI and correlate IVUS measurements with clinical, procedural, imaging and follow-up outcomes of interest.

Study participants will undergo primary PCI as per standardized procedures; IVUS will be performed at baseline, post-intervention and post-optimization. Manual thrombus aspiration will be performed according to clinical indications. The aspirated thrombi will be collected and scanned with micro-computed tomography (micro-CT). Also, angiographic and peri-procedural data will be gathered. Post-PCI instantaneous wave-free ratio (IFR) will also be performed to assess the severity of the residual coronary-artery stenosis, if any. All patients will be followed up for at least12 months for the adjudication of major adverse cardiovascular events.

The ULTRA-STEMI trial is a prospective investigator-initiated single-centre single-arm observational cohort study aiming to enroll 80 consecutive patients presenting with ST-segment elevation myocardial infarction (STEMI) and undergoing IVUS-guided primary PCI. IVUS will be performed at baseline, post-intervention and post-optimization. Baseline tissue characterization includes the morphological description of culprit lesion plaque and thrombus characteristics as assessed with IVUS. In patients with large thrombus burden, manual thrombus aspiration will be performed according to clinical indications. The aspirated thrombi will be collected and scanned with micro-computed tomography (micro-CT) to correlate IVUS measurements with micro-CT thrombus quantification. Also, angiographic data will be gathered to correlate IVUS measurements with pre-and post-PCI angiographic information. Post-PCI instantaneous wave-free ratio (IFR) will also be performed to assess the severity of the residual coronary-artery stenosis, if any. All patients will be followed up for at least 12 months for the adjudication of major adverse cardiovascular events.The primary endpoint will be target vessel failure at 12 months (defined as a composite of cardiac death, target vessel myocardial infarction and clinically driven target vessel revascularization). The secondary outcomes of interest will be: radiation exposure, contrast use and kidney function effects. Other endpoints include clinical and angiographic outcomes along with post-PCI IVUS, iFR and micro-CT findings.

Inclusion Criteria:

1. Patients with acute STEMI undergoing primary PCI within 12 hours of symptom onset according to the 4th universal definition of myocardial infarction.
2. Age >18 years
3. Individuals willing to voluntarily sign the consent and data protection forms before their inclusion in the clinical study.

Exclusion Criteria:

1. Patients presenting with cardiogenic shock
2. Patients with a known contraindication for primary PCI
3. Pregnancy
4. Presentation ≥12 hours after symptom onset