The aim of this study is to determine the progression of coronary artery calcification (CAC) using electron beam computed tomography (CT) when the initial CAC score (CACS) is zero and to determine the best interval to repeat a CAC scan. We studied 388 individuals with zero CACS (308 males; mean age: 48.8 ± 8.26 years) who underwent 2 consecutive CT scans in a period of at least 12 months apart. The interscan period was 2.99 ± 1.35 years (range: 1-6 years). Three-quarters of the individuals (75%) did not develop any CAC progression, 20.87% presented CAC progression of 1 to 10, 3.6% had 11 to 50, whereas only 0.51% had >50. The average time of new CAC development was 4.2 ± 1.1 years. Individuals with CAC progression presented higher incidence of hypertension, diabetes mellitus, hypercholesterolaemia and higer frequency of male gender than those with without CAC changes (p<0.02). No cardiac events occurred during the follow-up period.

Although several studies have demonstrated the association between coronary artery calcification (CAC) and coronary artery disease events, the underlying mechanism has not been fully elucidated. Furthermore, extensive CAC still remains a poorly understood phenomenon. The objective of this study is to determine the clinical characteristics and differences between 831 asymptomatic individuals with very high CAC scores (CACS ≥ 1000) and 497 asymptomatic individuals with CAC scores of 400 to 999. Individuals with CACS ≥ 1000 were more likely to have hypertension ([HTN]; P = .0004), hypercholesterolemia (P = .0001), diabetes mellitus ([DM] P = .005), and high body mass index ([BMI]; P = .03) compared with individuals with CACS = 400-999. On multivariable analysis, age (P < .0001) and BMI (P = .01) were found to be significant risk factors for the presence of very high CAC. While for males, age (P < .0001), hypercholesterolemia (P = .001), DM (P = .002), and obesity (P = .003) were independent risk factors; in females only HTN (P = .04) was independent risk factor.

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