December 13, 1952BMJ562 citationsOpen Access
Study of the Aetiology of Carcinoma of the Lung
Key Result
A total burden score combining carotid intima-media thickness and the number of segments with plaque improved 5-year ICVD risk prediction compared with conventional risk scores (NRI +17.1%).
Study Design
Type
Observational (n=1,734)
Structured PICO
Does a total burden score (TBS) of carotid atherosclerosis improve the prediction of ischaemic cardiovascular disease events compared to conventional risk scores in a Chinese cohort?
P
Population
1734 Chinese subjects (623 men, 1111 women) aged 43–79 years at baseline.
I
Intervention
Total burden score (TBS) of carotid atherosclerosis (combining carotid IMT and number of segments with plaque)
C
Comparator
Conventional risk score, IMT alone, or number of segments with plaque alone
O
Outcome
Ischaemic cardiovascular disease (ICVD) events, including coronary heart disease and ischaemic strokecomposite
A novel total burden score combining carotid IMT and plaque segments significantly improves the 5-year risk prediction of ischaemic cardiovascular disease over conventional risk scores.
Abstract
Background Several indices of carotid atherosclerosis have been studied to investigate their associations with the risk of cardiovascular disease. However, the best index of carotid atherosclerosis that predicts the risk of cardiovascular disease remains unclear. Objective To investigate the index that best reflects the relationship between carotid atherosclerosis and subsequent ischaemic cardiovascular disease (ICVD) events. Design An observational longitudinal study with a 5-year follow-up. Participants 1734 Chinese subjects (623 men, 1111 women) aged 43–79 years at baseline. Main outcome measures ICVD events, including coronary heart disease and ischaemic stroke. Results Carotid intima-media thickness (IMT) at baseline was significantly associated with the risk of ICVD among participants without carotid plaque (multivariable adjusted HR=1.59, 95% CI 1.04 to 2.45) but not among those with plaque (HR=1.04, 95% CI 0.78 to 1.39). However, the total area of plaques (HR=1.29, 95% CI 1.08 to 1.55), the number of plaques (HR=1.14, 95% CI 1.02 to 1.27) and the number of segments with plaque (HR=1.45, 95% CI 1.09 to 1.93) were all significantly associated with ICVD in participants with plaque. Thus, carotid IMT and the number of segments with plaque were combined to establish a summary index—the total burden score (TBS) of carotid atherosclerosis—which was shown to improve the prediction of the 5-year risk of ICVD significantly compared with IMT or the number of segments with plaque alone. The c-statistics and net reclassification index showed that TBS improved the risk prediction by increases of 6.0% and 17.1%, respectively, compared with the conventional risk score. Conclusion The TBS could significantly improve the prediction of ICVD risk and should be used in clinical practice and future studies.