In order to compensate for the shortcomings of not knowing the atherosclerotic burden of a subject, determination of carotid atherosclerosis as a validated marker of coronary and stroke risk can be used to define arterial age. Determining the arterial age may be more convincing for both patients and doctors. Therefore, use of noninvasive, radiation-free methods for determining the atherosclerotic burden of subjects is most desirable. Use of the Framingham vascular age and risk functions to calculate arterial age has led to the realisation that, although it would be helpful in communicating risk to patients, there was no underlying determination of atherosclerotic burden. An arterial age using coronary artery calcium score has been derived from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, where replacing observed age with arterial age performed significantly better in the area under the receiver operating curve. It has been suggested that arterial age can be used instead of the chronological age in risk functions since chronological age is only a surrogate of the atherosclerotic burden on the basis of carotid intima-media thickness. The heart age in the Framingham Heart Study is calculated as the age of a person at the predicted risk but with all other risk factor levels in normal ranges. Since increasing age can be dominant over other major independent cardiovascular risk factors in coronary risk functions, it has become appropriate to determine the vascular/arterial age of a subject. ROC receiver operator characteristic IntroductionĪrterial age is considered to be a marker for biological age and Grundy probably described it best when he paraphrased William Osler, who first observed that by transforming age as a risk factor, patients are as old as their arteries. TPA total plaque area of the carotid arteries Further studies on the external validity and cost effectiveness of the additional ultrasound imaging study are necessary.ĪGLA Arbeitsgruppe Lipide und Atherosklerose (Swiss coronary risk calculator) This finding was also confirmed by a Cox proportional hazards regression model on patients' event-free survival (p = not significant for AGLAca, p = 0.0003 for AGLAaa).ĬONCLUSIONS: Arterial age derived from TPA could be used instead of chronological age in the AGLA coronary risk function. Receiver operating characteristic (ROC) analysis of AGLAca and AGLAaa results showed areas under the curve of 0.65 (p = 0.041) and 0.78 (p <0.0001), respectively, (p = 0.041 for the difference = 0.13). Mean 10-year AGLAca coronary risk was comparable to AGLAaa (8% ± 9% vs 9% ± 15%). Arterial age was found to be y = 5.4175e0.0426x in men and y = 4.1942e0.0392x in women. RESULTS: The derivation cohort included 1,500 subjects (mean age 59 ± 9 years, mean TPA 54 ± 52 mm 2, 5% diabetics, 43% women). AGLAca and AGLAaa were tested externally for their ability to detect 13 myocardial infarctions in 684 subjects (validation cohort). The arterial age formula was found by fitting an exponential function on these data. ![]() In this derivation cohort, sex-specific 5-year groups of mean TPA were calculated in subjects aged between 35 and 79 years. METHODS: In a practice based sample, burden of carotid plaque was obtained with ultrasound, using total plaque area (TPA). PRINCIPLES: As a result of the relatively low sensitivity of coronary risk charts, such as the Swiss coronary risk calculator (Arbeitsgruppe Lipide und Atherosklerose, AGLA), for detecting subjects with future myocardial infarction, the performance of arterial age (aa) as a surrogate marker for chronological age (ca) was tested.
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