Subclinical Coronary Artery Disease as Detected by Coronary Computed Tomography Angiography in an Asymptomatic Population

BACKGROUND AND OBJECTIVES: Primary prevention of coronary artery disease (CAD) has become a public health issue, according to increasing awareness of the substantial risks posed by asymptomatic atherosclerosis. The aims of this study were to determine the prevalence and characteristics of subclinical CAD using coronary computed tomography angiography (CCTA), and to evaluate the role of this advanced technology in identifying subclinical CAD in asymptomatic Korean individuals, compared with conventional risk stratification. SUBJECTS AND METHODS: We enrolled 4,320 consecutive asymptomatic individuals (61% males, aged 50+/-9 years), who underwent 64-slice CCTA during a routine health check. RESULTS: Coronary artery plaques were present in 1,053 (24%) individuals. Significant stenosis (diameter stenosis > or =50%) was identified in 139 (3%) subjects, and most of the significant lesions (87%) were located in the left anterior descending artery. CCTA revealed noncalcified plaques in 5% of subjects with a coronary calcium score of zero (n=801). Although 25% (n=10) of those with noncalcified plaque had significant stenosis, most of them (90%) were classified into low- or moderate-risk groups according to National Cholesterol Education Program risk stratification guidelines. In a young population (age < or =55 years for males, < or =65 years for females), 30% of subjects with significant stenosis were classified into a low-risk group and 60% had low (0 to 100) calcium scores. CONCLUSION: Subclinical CAD in asymptomatic individuals cannot be ignored for its considerable prevalence, CCTA may be helpful in identifying at-risk subclinical CAD in a noninvasive manner, especially in the young and traditionally low-risk population.

Association of Lipoprotein Lipase Gene Polymorphism and Coronary Artery Disease in Korean

BACKGROUND: The accumulation of lipoprotein and monocyte in the intima of the arterial wall is the most important step of the development of coronary artery disease (CAD). Lipoprotein lipase (LPL) plays an anti-atherogenic role by lipolysis of triglyceride-rich lipoproteins, but, it may also act as a receptor of some lipoproteins and monocyte at the arterial wall and act as a atherogenic molecule. Previous studies showed somewhat contradictory results about the association of CAD and LPL polymorphisms and mutations. Racial and dietary difference may contribute to these contradictory results. In this study, we tried to find out the association of CAD and the genetic variation of the LPL (PvuII RFLP in intron 6, HindIII RFLP in intron 8 and Ser 447 Ter mutation in exon 9) in Korean population. METHOD AND RESULT: CAD patients (n=146), confirmed by coronary angiography and healthy Korean adult volunteers (n=110) were genotyped for PvuII/HindIII RFLP and Ser447Ter mutation of the LPL gene by PCR-digestion method. Between two groups, the genotype frequency of these genetic variations was not different. But, the genetic variations showed different effect on lipid profile and body mass index (BMI) in the CAD group and in the control group. In the CAD group, P1 allele carriers showed higher total cholesterol (P1P1+P1P2:P2P2=216+-51 mg/dl:198+/-38 mg/dl, p=0.039) and higher LDL cholesterol level (P1P1+P1P2:P2P2=143+/-46 mg/dl:126+/-36 mg/dl, p=0.047), and H1 allele carriers had lower Body mass index than non-carriers (23.8+/-2.3 kg/m2 :24.8+/-2.9 kg/m2 , p=0.047). In the control group, the Ser447Ter mutation carriers had higher HDL cholesterol level than non-carriers (59+/-10mg/dl versus 53+/-11mg/dl, p=0.049) and patients with P1 allele showed lower body mass index (P1P1+P1P2: P2P2=23.1+/-2.6 kg/m 2 :24.5+/-2.6 kg/m2 , p=0.006). CONCLUSION: In Korean, PvuII/HindIII RFLP and Ser447Ter mutation was not associated with CAD, and they showed different effect on the lipid profile and on the body mass index according to the study group. These results suggests that the phenotypic characteristics of the LPL gene of the Korean people are different from those of occidental people.