Napkin-ring sign on coronary CT angiography for the prediction of acute coronary syndrome
Kenichiro Otsuka, Shota Fukuda, Atsushi Tanaka, Koki Nakanishi, Haruyuki Taguchi, Junichi Yoshikawa, Kenei Shimada, Minoru Yoshiyama, Kenichiro Otsuka, Shota Fukuda, Atsushi Tanaka, Koki Nakanishi, Haruyuki Taguchi, Junichi Yoshikawa, Kenei Shimada, Minoru Yoshiyama
Abstract
Objectives: The aim of this study was to determine the predictive value of the napkin-ring sign on coronary computed tomography angiography (CTA) for future acute coronary syndrome (ACS) events in patients with coronary artery disease.
Background: Recent studies have reported a close association between the napkin-ring sign on coronary CTA and thin-cap fibroatheroma.
Methods: The subjects of this prospective study were 895 consecutive patients who underwent coronary CTA examination and were followed for >1 year. The primary endpoint was an ACS event (cardiac death, nonfatal myocardial infarction, or unstable angina pectoris). The coronary CTA analysis included the presence of obstructive plaque, positive remodeling (PR), low-attenuation plaque (LAP), and the napkin-ring sign. The napkin-ring sign was defined by the following criteria: 1) the presence of a ring of high attenuation around certain coronary artery plaques; and 2) attenuation of the ring presenting higher than those of the adjacent plaque and no >130 Hounsfield units.
Results: Of the 12,727 segments, 1,174 plaques were observed, including plaques with PR in 130 segments (1.0%), LAP in 107 segments (0.8%), and napkin-ring signs in 45 segments (0.4%). Thirty-six of the 45 plaques with napkin-ring signs (80%) overlapped with those showing either PR or LAP. During the follow-up period (2.3 ± 0.8 years), 24 patients (2.6%) experienced ACS events, and plaques developed in 41% with a napkin-ring sign. Segment-based Cox proportional hazards models analysis showed that PR (p < 0.001), LAP (p = 0.007), and the napkin-ring sign (p < 0.0001) were independent predictive factors for future ACS events. Kaplan-Meier analysis demonstrated that plaques with napkin-ring signs showed a higher risk of ACS events compared with those without a napkin-ring sign.
Conclusions: The present study demonstrated for the first time that the napkin-ring sign demonstrated on coronary CTA was strongly associated with future ACS events, independent of other high-risk coronary CTA features. Detection of the napkin-ring sign could help identify coronary artery disease patients at high risk of future ACS events.
Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
Source: PubMed