Common carotid intima-media thickness measurements in cardiovascular risk prediction: a meta-analysis.
Level 1 - systematic review of randomized trials
Individual participant data meta-analysis of prospective cohort studies for a prognostic/risk prediction question.
PubMed 22910757 · doi:10.1001/jama.2012.9630
What was done
Databases (PubMed from 1950 to June 2012, EMBASE from 1980 to June 2012) and expert opinion were searched to identify general-population studies measuring baseline common carotid intima-media thickness (CIMT) with follow-up for first-time myocardial infarction or stroke. Individual participant data from individuals without pre-existing cardiovascular disease were combined into one dataset. Risk factors from the Framingham Risk Score were refitted and extended with common CIMT measurements to estimate absolute 10-year risks, evaluating changes in C statistics and net reclassification improvement.
What was found
The analysis included 14 population-based cohorts comprising 45,828 individuals followed for a median of 11 years, during which 4,007 first-time myocardial infarctions or strokes occurred. The C statistic remained similar between the refitted Framingham model (0.757; 95% CI, 0.749-0.764) and the model extended with common CIMT (0.759; 95% CI, 0.752-0.766). Overall net reclassification improvement with common CIMT was 0.8% (95% CI, 0.1%-1.6%). In individuals at intermediate risk, net reclassification improvement was 3.6% (95% CI, 2.7%-4.6%), with no differences between men and women.
Why it matters
Adding common CIMT measurements to the Framingham Risk Score produces negligible improvements in cardiovascular risk prediction that are unlikely to be clinically meaningful in routine screening.
Limits
The analysis evaluated only common CIMT measurements and did not evaluate carotid plaque presence or other carotid segments. Findings are restricted to individuals without existing cardiovascular disease in general-population cohorts.
Cited by
- context Carotid intima-media thickness (IMT) measured by ultrasound is an indicator of whole-body cardiovascular status.