Hiroyuki Takaoka MD, PhD, Presenter: Nothing to Disclose

Nobusada Funabashi MD, PhD, Abstract Co-Author: Nothing to Disclose

Masae Uehara MD, Abstract Co-Author: Nothing to Disclose

Yoshio Kobayashi, Abstract Co-Author: Nothing to Disclose

To evaluate patient prognosis after coronary CT and compare the risk of major adverse cardiac events (MACE) between patients with and without non-calcified plaques (NCP), or calcified plaques (CP) using a Kaplan-Meier analysis and a Cox proportional hazard model.

A total of 296 consecutive patients with suspected coronary artery disease (172 male, mean age 64.9 ± 12.0 years, hypertension, 62%; diabetes mellitus, 27%; dyslipidemia, 48%; smokers, 46%; and obese, 32%), who underwent coronary CT (Light speed Ultra 16, GE Healthcare) from 2003 to 2004 were included. The patients were followed for a median of 63.2 ± 32.6 months after coronary CT. The incidence of MACE was compared with a Kaplan-Meier analysis and the log rank statistic.

39% had NCP and 75% had CP. 13 had a MACE, including coronary revascularization because of ischemic events and cardiac death after coronary CT. Patients with NCP had a higher risk of MACE (7.9%) than those without (2.2%; p=0.02) during the observation period. Significant differences between the subjects with and without NCP were seen at each time point and when the whole period of follow-up was compared with a Kaplan-Meier analysis and log rank test (p=0.02; Figure 1). A Cox proportional hazards model was used to test the significance of NCP as a predictor of MACE considering the influence of age, male sex, hypertension, dyslipidemia, smoking habits, and obesity. This analysis revealed that NCP was predictor of MACE (Hazard ratio 3.65, p=0.01). Patients with CP had a higher risk of MACE (5.9%) than those without (0%) (p=0.03) during the observation period. A significant difference between the subjects with and without CP was also seen at each time point and when the whole period of follow-up was compared with a Kaplan-Meier analysis and log rank test (p=0.02; Figure 2). But a Cox proportional hazards model revealed that CP was not predictor of MACE.  

Patients with NCP on coronary CT had a higher risk of MACE than those without following a median of 63 months using a Kaplan-Meier analysis and Cox proportional hazard regression with a hazard ratio of 3.65.

The influence of NCP on the incidence of MACE was stronger than that of CP. Evaluation for NCP on enhanced CT may be more important than for CP on non-enhanced CT.

Takaoka, H, Funabashi, N, Uehara, M, Kobayashi, Y, Higher Risk Prognosis for Major Cardiac Events in Patients with Noncalcified Plaques on Coronary CT Following a Median of 63 Months Using Kaplan-Meier Analysis and Cox Proportional Hazard Regression.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11020006.html