This study is an investigator-led prospective study of 'Virtual Histology'-intravascular ultrasound (VH-IVUS) in patients with acute coronary syndrome or stable angina undergoing PCI. VH-IVUS is based upon spectral analysis of ultrasound backscatter, with different plaque components exhibiting a defined spectrum.

The radiofrequency signal is mathematically transformed into a colour-coded representation, including lipid, fibrous tissue, calcification, and necrotic core. 170 patients were prospectively enrolled and underwent 3-vessel VH-IVUS pre-PCI, in both stable angina and acute coronary syndrome patients (primary PCI). Troponin-I (cTnI) was measured pre-PCI and 24 hours post-PCI. The combined primary endpoint of major adverse cardiovascular events (MACE) included unplanned revascularization, myocardial infarction (MI) and death, with a secondary endpoint of post-PCI MI (MI 4a). This study shows that this new imaging technique can prospectively identify patients at high risk for MACE, validating the technique for interventional studies and to identify high-risk patients for targeted treatment. The study was funded by the BRC, and then subsequently supported by the BHF.