| Popis: |
This study sought to quantify and model conversion of a normal coronary artery calcium (CAC) scan to an abnormal CAC scan.Although the absence of CAC is associated with excellent prognosis, progression to CAC0 confers increased risk. The time interval for repeated scanning remains poorly defined.This study included 3,116 participants from the MESA (Multi-Ethnic Study of Atherosclerosis) with baseline CAC = 0 and follow-up scans over 10 years after baseline. Prevalence of incident CAC, defined by thresholds of CAC0, CAC10, or CAC100, was calculated and time to progression was derived from a Weibull parametric survival model. Warranty periods were modeled as a function of sex, race/ethnicity, cardiovascular risk, and desired yield of repeated CAC testing. Further analysis was performed of the proportion of coronary events occurring in participants with baseline CAC = 0 that preceded and followed repeated CAC testing at different time intervals.Mean participants' age was 58 ± 9 years, with 63% women, and mean 10-year cardiovascular risk of 14%. Prevalence of CAC0, CAC10, and CAC100 was 53%, 36%, and 8%, respectively, at 10 years. Using a 25% testing yield (number needed to scan [NNS] = 4), the estimated warranty period of CAC0 varied from 3 to 7 years depending on sex and race/ethnicity. Approximately 15% of participants progressed to CAC10 in 5 to 8 years, whereas 10-year progression to CAC100 was rare. Presence of diabetes was associated with significantly shorter warranty period, whereas family history and smoking had small effects. A total of 19% of all 10-year coronary events occurred in CAC = 0 prior to performance of a subsequent scan at 3 to 5 years, whereas detection of new CAC0 preceded 55% of future events and identified individuals at 3-fold higher risk of coronary events.In a large population of individuals with baseline CAC = 0, study data provide a robust estimation of the CAC = 0 warranty period, considering progression to CAC0, CAC10, and CAC100 and its impact on missed versus detectable 10-year coronary heart disease events. Beyond age, sex, race/ethnicity, diabetes also has a significant impact on the warranty period. The study suggests that evidence-based guidance would be to consider rescanning in 3 to 7 years depending on individual demographics and risk profile. |
