Skip to main page content

• Original Article

Thin-Cap Fibroatheroma as High Risk Plaque for Microvascular Obstruction in Patients With Acute Coronary Syndrome

1. Yuichi Ozaki, 
2. Atsushi Tanaka*, 
3. Takashi Tanimoto, 
4. Hironori Kitabata,
5. Manabu Kashiwagi, 
6. Takashi Kubo, 
7. Shigeho Takarada, 
8. Kohei Ishibashi,
9. Kenichi Komukai, 
10. Yasushi Ino, 
11. Kumiko Hirata, 
12. Masato Mizukoshi,
13. Toshio Imanishi and 
14. Takashi Akasaka

+Author Affiliations

1. Wakayama Medical University, Japan

1. ↵* Corresponding author; email: a-tanaka@wakayama-med.ac.jp

Abstract

Background—Plaque contents can cause microvascular impairment, which is an important determinant of clinical outcomes in patients with acute coronary syndrome (ACS). We hypothesized that percutaneous coronary intervention (PCI) for thin-cap fibroatheroma (TCFA) could easily disrupt the fibrous cap and expose the contents of plaque to coronary flow, possibly resulting in microvascular obstruction (MVO). The purpose of this study was to investigate whether TCFA was associated with MVO following PCI in patients with ACS.

Methods and Results—We enrolled 115 patients with ACS who were successfully recanalized with PCI. The patients were divided into a ruptured plaque group (n=59), a non-rupture with TCFA group (n=21), and a non-rupture and non-TCFA group (n=35) according to optical coherence tomography findings of the culprit lesion. Using contrast-enhanced magnetic resonance imaging, we assessed MVO. There were no statistically significant differences in patient's characteristics. The non-rupture with TCFA group more frequently presented MVO (ruptured plaque 27% vs. non-rupture with TCFA 43% vs. non-TCFA and non-rupture 9%, P=0.012). The prevalence of MVO increases as cap thickness decreases.

Conclusions—TCFA is more frequently associated with MVO following PCI. TCFA is a high-risk plaque for MVO following PCI in patients with ACS.