Incidence of subclinical atherosclerosis as assessed with electron beam CT in adults ≤45 years old

Abstract

Coronary atherosclerosis is a continuous process beginning early in life, with a long and clinically asymptomatic phase, before manifestations appear in middle and/or late adulthood. Coronary artery calcification (CAC) is a well-established marker of atherosclerosis; nonetheless, the clinical validity of CAC in young adults – traditionally considered as a population group of low cardiovascular risk – remains unclear. We aimed to assess the prevalence of CAC in a population of young individuals without previous history of coronary artery disease (CAD) in the UK and its association with conventional cardiovascular risk factors. This analysis includes 4186 asymptomatic young individuals who underwent electron beam computed tomography (EBCT) at European Scanning Centre (London, UK) between January 2002 and December 2009 as part of a preventive healthcare examination. Demographic information and the presence of cardiovascular risk factors were abstracted from referral letters and/or questionnaires completed by the patients prior to their tests. Individuals with previously documented CAD or chronic kidney disease were excluded. All EBCT CAC studies were performed using the same scanner (Imatron C300 Ultrafast computed tomography scanner, GE Healthcare, London, UK) and the same scanning protocol. The age (mean SD) of the study cohort was 40.5 3.6 years (range 26–45 years, 83.8% males). The majority (81.6%) of this cohort was Caucasians, followed by South Asians (8%). Hypertension, dyslipidaemia, and diabetes mellitus (DM) were present in 15.5, 7.9, and 2.8% of individuals, respectively. Family history of premature CAD was present in 17%, while 17.4% were smokers. The proportion of individuals with hypertension and dyslipidaemia increased with increasing age, while the prevalence of smoking and that of a positive family history for CAD decreased (Table 1). Overall, CAC was present in 21.8% of the cohort, while individuals with CAC comparing with those with CAC score 0 were males (95.2 vs. 80%, p 1000 were 78.2, 19, 2.1, 0.5, and 0.2%, respectively. The prevalence and distribution of CAC among various age groups are shown in Table 1. CACwas found in 24.8%ofmales (CAC score 1–100, 101–400, 400–1000, >1000 in 21.6, 2.5, 0.5, and 0.1%, respectively) and 6.6% of females (CAC score 1–100, 101–400, 400–1000, >1000 in 5.4, 0.6, 0.15 and 0.4%, respectively) (p 0) was identified in 20%. There was a male preponderance. Assessment of CAC score is a useful clinical tool in young individuals, as it can confirm the presence of subclinical atherosclerosis. In this way, the abnormal levels of calcium may place individuals into a higher risk group in terms of future events and lead to more aggressive treatment with preventative therapies.