Very rarely can one give a warranty in Medical Sciences. In such a situation, it become eye-cathing when a researcher comes out and makes a claim that there may exist a A 15-year warranty period for asymptomatic individuals without CAC.
This result comes as a conclusion of a follow-up study done by Valenti and colleagues who sought to study the long-term (15-year) prognosis in asymptomatic individuals with a CAC score of 0, quantifying the “warranty period” of this finding.
A total of 9,715 individuals undergoing CAC imaging were stratified by age, Framingham risk score (FRS), and National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) categories and followed for a mean of 14.6 years. A warranty period was pre-defined as <1% annual mortality rate. Vascular age was estimated by linear regression.
During follow-up, of the 4,864 individuals with a baseline CAC score of 0, 229 deaths occurred (4.7%). Fifteen-year survival was 95.1% for those with CAC 0 compared with 83.7% for those with CAC >O. On multivariate analysis, a CAC score >O was the strongest predictor of death in the overall population beyond individual cardiovascular risk factors, FRS, and NCEP ATP III
The calculated warranty period of a CAC score of 0 was almost 15 years for individuals at low and intermediate risk with no significant differences regarding age and sex. Also, a CAC score of 0 was associated with a vascular age 30 years less than the chronological age of individuals 80 years of age and older, with similar but less pronounced findings in younger patients.
The reseracher concluded that a CAC score of 0 confers a 15-year warranty period against mortality in individuals at low to intermediate risk irrespective of age or sex. In those considered at high risk based on clinical risk scores, a CAC score of 0 confers better survival than in individuals at low to intermediate risk but with a CAC score>O.
The authors also talked about the concept of Vascular Youth- those who are aged 50 and more and yet have a CAC score of Zero.
1.Valenti V, O’ Hartaigh B, Heo R, et al (Min JK, senior author). A 15-year warranty period for asymptomatic individuals without coronary artery calcium. Prospective follow-up of 9,715 individuals. JACC Cardiovasc Imaging. 2015; 8: 900-9.