In vivo detection of high-risk coronary plaques by radiofrequency intravascular ultrasound and cardiovascular outcome: results of the ATHEROREMO-IVUS study

Abstract

Aims: Acute coronary syndromes (ACS) are mostly caused by plaque rupture. This study aims to investigate the prognostic value of in vivo detection of high-risk coronary plaques by intravascular ultrasound (IVUS) in patients undergoing coronary angiography.

Methods and results: Between November 2008 and January 2011, IVUS of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography for ACS (n = 318) or stable angina (n = 263). Primary endpoint was major adverse cardiac events (MACEs) defined as mortality, ACS, or unplanned coronary revascularization. Culprit lesion-related events were not counted. Cumulative Kaplan-Meier incidence of 1-year MACE was 7.8%. The presence of IVUS virtual histology-derived thin-cap fibroatheroma (TCFA) lesions (present 10.8% vs. absent 5.6%; adjusted HR: 1.98, 95% CI: 1.09-3.60; P = 0.026) and lesions with a plaque burden of ≥70% (present 16.2% vs. absent 5.5%; adjusted HR: 2.90, 95% CI: 1.60-5.25; P < 0.001) were independently associated with a higher MACE rate. Thin-cap fibroatheroma lesions were also independently associated with the composite of death or ACS only (present 7.5% vs. absent 3.0%; adjusted HR: 2.51, 95% CI: 1.15-5.49; P = 0.021). Thin-cap fibroatheroma lesions with a plaque burden of ≥70% were associated with a higher MACE rate within (P = 0.011) and after (P < 0.001) 6 months of follow-up, while smaller TCFA lesions were only associated with a higher MACE rate after 6 months (P = 0.033).

Conclusion: In patients undergoing coronary angiography, the presence of IVUS virtual histology-derived TCFA lesions in a non-culprit coronary artery is strongly and independently predictive for the occurrence of MACE within 1 year, particularly of death and ACS. Thin-cap fibroatheroma lesions with a large plaque burden carry higher risk than small TCFA lesions, especially on the short term.

Keywords: Atherosclerosis; Intravascular ultrasound; Natural history; Prognosis; Thin-cap fibroatheroma; Virtual histology.