Distribution and Frequency of Thin-Capped Fibroatheromas and Ruptured Plaques in the Entire Culprit Coronary Artery in Patients With Acute Coronary Syndrome as Determined by Optical Coherence Tomography

The aim of this study was to investigate the distribution and frequency of thin-capped fibroatheromas (TCFAs) within the entire length of culprit coronary arteries in patients with acute coronary syndrome. Our population was drawn from 43 consecutive patients with acute coronary syndrome (with or without ST-segment elevation) who underwent optical coherence tomography to visualize the entire culprit coronary artery using a nonocclusive optical coherence tomographic technique. Patients were categorized divided into a TCFA group or a no-TCFA group on the basis of the optical coherence tomographic findings. There were no differences in baseline characteristics or angiographic findings between the 2 groups. High-sensitive C-reactive protein in the TCFA group was significantly higher than in the no-TCFA group (median 3.3 mg/L, interquartile 3.1, vs 1.7 mg/L, interquartile 2.2, p = 0.03). Plaque rupture was found in 28 patients (65%) and multiple plaque ruptures in 5 patients (12%). Optical coherence tomogram revealed 21 TCFAs in 18 patients (42%). Multiple TCFAs were found in the same vessel in 3 patients (7%). The distribution of TCFAs in the right coronary arteries of our subject population was relatively even (proximal 2 [12%], mid 5 [29%], distal 3 [18%], p = 0.42), whereas TCFAs in the left anterior descending artery were common in proximal sites (proximal 6 [27%], mid 2 [9%], distal 0, p = 0.018). In conclusion, the use of optical coherence tomography to look for TCFAs and identify their distribution when combined with C-reactive protein may contribute to forming a strategy for preventing impending coronary events.