Relationship between markers of plaque vulnerability in optical coherence tomography and atherosclerotic progression in adult patients with heart transplantation

Background Cardiac allograft vasculopathy (CAV) is an accelerated form of coronary artery disease, and optical coherence tomography (OCT) provides detailed microstructural information. The current study was designed to test the hypothesis that markers of plaque vulnerability derived from OCT could predict CAV progression after heart transplantation (HTx). Methods In 34 consecutive patients (median 3.1 years from HTx), intravascular ultrasound (IVUS) and OCT were performed in the left anterior descending artery (LAD) during routine annual coronary angiography. The presence of vulnerability markers, such as lipid pools, thin-cap fibroatheroma, macrophages and microchannels, was assessed in 100 consecutive frames of OCT in 20-mm segments of proximal LAD. The total number of appearances of vulnerable markers was defined as the vulnerability score (VS). Plaque volume (PV) was measured in the same study segment using IVUS at baseline and at 1-year follow-up, and the association between the baseline VS and the subsequent change in percent PV (PV / vessel volume × 100 [%PV]) was evaluated. Results Follow-up IVUS study was conducted after 12.5 ± 1.3 months. The mean VS was 59.9 ± 44.6. Compared with the initial %PV, the follow-up %PV increased in the study segment (25.6 ± 13.7% to 31.8 ± 17.5%, p < 0.001). The correlations between baseline VS and Δ%PV were significant in the study segment (r = 0.757, p < 0.001). On multivariable analysis, only the VS correlated significantly with Δ%PV. Conclusions Our results demonstrate that the markers of plaque vulnerability in OCT can predict the progression of CAV. Therefore, in patients with HTx, OCT may aid in determining prognosis and guiding therapy related to CAV.