Clinical Research
Coronary Artery Disease
Carotid Intima-Media Thickness and Presence or Absence of Plaque Improves Prediction of Coronary Heart Disease Risk: The ARIC (Atherosclerosis Risk In Communities) Study

https://doi.org/10.1016/j.jacc.2009.11.075Get rights and content
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Objectives

We evaluated whether carotid intima-media thickness (CIMT) and the presence or absence of plaque improved coronary heart disease (CHD) risk prediction when added to traditional risk factors (TRF).

Background

Traditional CHD risk prediction schemes need further improvement as the majority of the CHD events occur in the “low” and “intermediate” risk groups. On an ultrasound scan, CIMT and presence of plaque are associated with CHD, and therefore could potentially help improve CHD risk prediction.

Methods

Risk prediction models (overall, and in men and women) considered included TRF only, TRF plus CIMT, TRF plus plaque, and TRF plus CIMT plus plaque. Model predictivity was determined by calculating the area under the receiver-operating characteristic curve (AUC) adjusted for optimism. Cox proportional hazards models were used to estimate 10-year CHD risk for each model, and the number of subjects reclassified was determined. Observed events were compared with expected events, and the net reclassification index was calculated.

Results

Of 13,145 eligible subjects (5,682 men, 7,463 women), ∼23% were reclassified by adding CIMT plus plaque information. Overall, the CIMT plus TRF plus plaque model provided the most improvement in AUC, which increased from 0.742 (TRF only) to 0.755 (95% confidence interval for the difference in adjusted AUC: 0.008 to 0.017) in the overall sample. Similarly, the CIMT plus TRF plus plaque model had the best net reclassification index of 9.9% in the overall population. Sex-specific analyses are presented in the manuscript.

Conclusions

Adding plaque and CIMT to TRF improves CHD risk prediction in the ARIC (Atherosclerosis Risk In Communities) study.

Key Words

CIMT
plaque
risk prediction

Abbreviations and Acronyms

ACRS
ARIC coronary risk score
AUC
area under the receiver-operating characteristic curve
CHD
coronary heart disease
CI
confidence interval
CIMT
carotid intima-media thickness
IDI
integrated discrimination improvement
MI
myocardial infarction
NRI
net reclassification index
TRF
traditional risk factors

Cited by (0)

The ARIC study is carried out as a collaborative study supported by National Heart, Lung, and Blood Institute (NHLBI)contracts N01-HC-55015, N01-HC-55016, N01-HC-55018, N01-HC-55019, N01-HC-55020, N01-HC-55021, and N01-HC-55022from the NHLBI, Bethesda, Maryland. Dr. Nambi has research collaboration with General Electric. Dr. Ballantyne is a consultant for Abbott, Astra Zeneca, Atherogenics, Bristol-Myers Squibb, KOWA, Metabsis, Merck, Merck-Schering-Plough, Novartis, Pfizer, Reliant, Schering-Plough, Sanofi-Synthelabo, Takeda, and GlaxoSmithKline; has received grant/research support from Abbott, ActivBiotics, AstraZeneca, Gene Logic, GlaxoSmithKline, Integrated Therapeutics, Merck, Pfizer, Schering-Plough, Sanofi-Synthelabo, and Takeda; is on the Speakers’ Bureau for AstraZeneca, GlaxoSmithKline, Merck, Pfizer, Reliant, and Merck-Schering-Plough, Schering-Plough; and has received honorarium from Merck, AstraZeneca, Abbott, GlaxoSmithKline, Merck-Schering-Plough, Novartis, Pfizer, Sanof-Synthelabo, Schering-Plough, and Takeda.