Calculating Vascular Age
The CIMT worksheet automatically calculates the patient’s vascular age based on “Use of Carotid Ultrasound to Identify Subclinical Vascular Disease and Evaluate Cardiovascular Disease Risk: A Consensus Statement from the American Society of Echocardiography Carotid Intima-Media Thickness Task Force, Endorsed by the Society for Vascular Medicine.” (James H. Stein, MD, FASE, et al, 2008)
For the vascular age to be calculated, the following fields must be populated:
- Patient's age
- Patient's gender
- Patient's race
- Mean or Max CIMT for the left distal CCA (dependent on applicable study data set)
- Mean or Max CIMT for the right distal CCA (dependent on applicable study data set)
If the patient’s demographics fall within the ranges for any of the studies listed below, and the patient’s relevant CIMT falls within the study’s data set, the vascular age is calculated.
| Race | Age | Study Data Set Used to Calculate Vascular Age |
|---|---|---|
Black White | >=25 and <=40 | Bogalusa |
| >40 and <45 | AXA | |
| >=45 and <=65 | ARIC | |
| >65 and <=84 | MEDA | |
| >84 and <=110 | CHS | |
Asian Hispanic or Latino | >=45 and <=84 | MESA |
| Independent of race, if none of the above conditions is met | >=30 and <=65 | AXA |
| >65 and <=110 | CHS |
If the patient does not meet any of these criteria, the vascular age is not calculated.
If a patient meets the criteria for more than one study, the more reliable study is used. For example, for a 45-year-old white male, both the ARIC study and AXA study could be used. However, the ARIC study was found to be more reliable. Therefore, in this case, the ARIC study is used to calculate the patient’s vascular age.
Vascular age is calculated based on the higher of the left and right distal CCA percentile. When ARIC, MESA, and AXA are used, the vascular age is based on the mean CCA distal value. When Bogalusa and CHS are used, the vascular age is based on the max CCA distal value. The average of the mean or max CCA distal right and left values is never used because it could inaccurately indicate a lower risk.
Some study data sets provide values only for specific ages. When these studies are used, if the patient’s relevant CIMT value falls between the 50th percentile values for two adjacent ages, the vascular age is calculated based on where it falls in the range between the two 50th percentile values.
For cases in which the study data set provides values for age ranges, if the relevant CIMT value falls on the 50th percentile for an age range, the mean age for that range is selected as the vascular age. If the relevant CIMT falls between the 50th percentile values for two adjacent age ranges, the vascular age will be either the upper bound of the lower age range or the lower bound of the higher age range, depending on which is closer to the mean CIMT value.