The Relationship between coronary artery calcification as assessed by multi-detector computed tomography and arterial stiffness

Pulse wave analysis and intima-media thickness (IMT) of carotid artery are the non-invasive indicators of subclinical atherosclerosis. Coronary artery calcification (CAC) score measured by multi-detector computed tomography (MDCT) is well known as a predictor of coronary heart disease (CHD). We investigated the association between coronary calcification assessed by MDCT and extracoronary atherosclerosis measured by pulse wave analysis and IMT of carotid artery. Arterial stiffness and carotid IMT were measured consecutively in 133 patients who underwent their first coronary MDCT angiography due to chest pain. Patients were divided into three groups according to the CAC score (group 1, score = 0, n = 62; group 2, 0 < score < 400, n = 58; group 3, score ≥ 400, n = 13). The classification of CAC score was associated with age, prevalence of hypertension and dyslipidemia, systolic blood pressure, pulse pressure, brachial-ankle pulse wave velocity, percentage of brachial mean artery pressure, upstroke time (UT), augmentation index, and carotid IMT. In a multivariate analysis, age (P = .048), hypertension (P = .007), dyslipidemia (P = .24), and mean ankle UT (P = .038) were independent variables for the classification of CAC score. The UT of pulse wave was significantly associated with the CAC score. The increased UT of pulse wave might provide incremental risk prediction in addition to that defined by conventional CHD risk assessment.     

Measurement of pulse wave velocity: site matters

BACKGROUND: Aortic pulse wave velocity (PWV) predicts mortality from cardiovascular disease, ischaemic heart disease and stroke. However, a comparison of associations between PWV measured at different sites and atherosclerosis in coronary, carotid and femoral arteries has not been made. METHODS: In 159 men (ages 45-82 years) with and without known coronary artery disease, PWV measurements were made between carotid-femoral, carotid-radial and femoral-posterior tibial sites, using an ultrasound technique. Coronary artery calcification (CAC) scores were measured by multislice computed tomography. Carotid and femoral intima-media thickness (IMT) and presence of plaque were determined by ultrasound. Known coronary artery disease was confirmed by angiography. Participants were grouped into four categories of CAC score: 0-10, 11-100, 101-400, > 400 Hounsfield Units (HU). Measurements of blood pressure, heart rate and fasting bloods were made in all individuals. RESULTS: Carotid-femoral PWV correlated positively with CAC score and increased with incremental coronary calcification category (median carotid-femoral PWV 16.8 m/s in those with CAC score > 400 HU and 13.8 m/s in those with CAC score < 10 HU; P = 0.003). Carotid-femoral PWV also correlated with carotid and femoral IMT (P < 0.001, P = 0.004, respectively) and with carotid and femoral plaque (P = 0.001, P = 0.038, respectively). Increased carotid-femoral PWV also correlated with increasing age (P < 0.001), systolic blood pressure (P < 0.001), mean arterial pressure and pulse pressure (P < 0.001). Carotid-radial and femoral-posterior tibial PWV were not significantly associated with CAC score, carotid or femoral IMT or carotid plaque. CONCLUSIONS: Carotid-femoral PWV is a better indicator of atherosclerosis than either carotid-radial or femoral-posterior tibial PWV, and should be used preferentially in studies of atherosclerosis and in stratifying risk in clinical settings.     

冠心病病人冠状动脉与颈动脉粥样硬化相关分析

目的 探讨冠心病病人颈动脉与冠状动脉粥样硬化的关系。方法 冠心病病人122例，经冠状动脉造影确诊，用颈动脉超声检测颈动脉内膜-中膜厚度（intima-media thickness，IMT）及粥样硬化程度。结果 病人病变冠状动脉支数分组间，IMT、颈动脉斑块积分和斑块发生率的差异有统计学意义。冠状动脉病变支数与IMT相关（r=0.73），与颈动脉斑块积分相关（r=0.67）。冠状动脉造影积分与IMT相关（r=0.69），与颈动脉斑块积分相关（r=0.68）。结论 冠心病病人颈动脉粥样硬化与冠状动脉粥样硬化呈正相关，颈动脉病变可间接反映冠状动脉粥样硬化病变程度。     

外周动脉粥样硬化与冠心病的相关性研究

目的探讨外周动脉粥样硬化与冠状动脉粥样硬化的关系及预测价值。方法对74例可疑冠心病患者行冠状动脉造影,其中确诊冠心病57例,正常17例。同时进行颈动脉、股动脉超声检查,对各动脉内膜中层厚度(IMT)、粥样硬化斑块及心血管危险因素同冠状动脉造影结果进行统计分析。依据修正的Gensin评分系统将冠状动脉积分,并以积分的大小进行等级评分,同时对外周动脉斑块对冠脉的预测价值、外周动脉IMT与冠脉积分的对数值进行相关性分析、冠心病组和正常组的危险因素之间进行统计分析。结果冠脉造影阳性组CA、FA的IMT和粥样硬化斑块发生率高于阴性组(P<0.05),颈动脉、股动脉粥样硬化对冠心病的阳性预测值分别为59.4%和53.1%,两处为阳性的阳性预测值是71.9%。颈动脉IMT与冠心病的log(Gensin评分)之间相关系数为0.891,股动脉IMT与冠心病的(Gensin评分)之间相关系数为0.75。结论外周动脉的粥样硬化是冠心病的相关因素,可作为研究冠状动脉粥样硬化的间接指标和窗口。     

高频超声评价颈动脉粥样硬化与冠状动脉病变的关系

目的利用高频超声检测颈动脉内中膜厚度(IMT)、斑块形成情况,并与冠状动脉(冠脉)病变程度的关系进行分析。方法应用ASPEN彩色多普勒超声诊断仪,对428例健康人(对照组)及89例冠心病患者(冠心病组)进行颈动脉IMT、斑块形成的检测。冠心病组患者以冠脉病变支数分为3个亚组。结果冠心病组患者颈动脉IMT为(1.19±0.14)mm,而对照组为(0.92±0.13)mm,(P<0.01);IMT增厚检出率及斑块形成检出率冠心病组为43.21%、74.65%,而对照组为14.49%、34.35%,(P<0.01)。1支冠脉病变组IMT为(1.00±0.014)mm,斑块形成检出率为42.86%;2支冠脉病变组IMT为(1.15±0.018)mm,斑块形成检出率为65.52%;3支及以上冠脉病变组IMT为(1.31±0.018)mm,斑块形成检出率为74.49%,(P<0.01)。结论颈动脉IMT增厚、斑块形成对冠心病具有预测价值;颈动脉IMT增厚、斑块形成与冠脉病变严重程度呈正相关。     

Subclinical atherosclerosis in northern and southern China: the Chinese paradox

Background The incidence of coronary heart disease (CHD) is higher in Northern than that in Southern China, however differences in traditional CHD risk factors do not fully explain this. No study has examined the differences in subclinical atherosclerosis that may help explain the differences in incidence. This study examined these differences in subclinical atherosclerosis using coronary computed tomography (CT) for calcification between the Northern and Southern China. Methods We selected a random sample of participants in a large multi-center ongoing epidemiologic study for coronary calcium scanning in one northern city (North) (Beijing, n = 49) and in two southern cities (South) (Shanghai, n = 50, and Guangzhou, n = 50). Participants from the three field centers (mean age 67 years) underwent coronary risk factor evaluation and cardiac CT scanning for coronary calcium measurement using the Multi-Ethnic Study of Atherosclerosis scanning protocol. Results Adjusted log-transformed coronary artery calcium score in North China (Beijing) was 3.1±0.4 and in South China (Shanghai and Guangzhou) was 2.2±0.3 (P = 0.04). Mean calcium score for the northern city of Beijing was three times higher than that of the southern city of Guangzhou (P = 0.01) and 2.5 times higher than for the southern city of Shanghai (P = 0.03). Conclusions The extent of subclinical atherosclerosis is significantly higher in the northern city of Beijing than that in the two southern cities of Guangzhou and Shanghai, even after adjusting for standard cardiac risk factors. This finding suggests that standard risk factors do not fully explain north south differences in clinical CHD incidence.     

Shared genetic architecture in the relationship between adult stature and subclinical coronary artery atherosclerosis

Background

Short stature is associated with increased risk of coronary heart disease (CHD); although the mechanisms for this relationship are unknown, shared genetic factors have been proposed. Subclinical atherosclerosis, measured by coronary artery calcification (CAC), is associated with CHD events and represents part of the biological continuum to overt CHD. Many molecular mechanisms of CAC development are shared with bone growth. Thus, we examined whether there was evidence of shared genes (pleiotropy) between adult stature and CAC.

Methods

877 Asymptomatic white adults (46% men) from 625 families in a community-based sample had computed tomography measures of CAC. Pleiotropy between height and CAC was determined using maximum-likelihood estimation implemented in SOLAR.

Results

Adult height was significantly and inversely associated with CAC score (P = 0.01). After adjusting for age, sex and CHD risk factors, the estimated genetic correlation between height and CAC score was −0.37 and was significantly different than 0 (P = 0.001) and −1 (P < 0.001). The environmental correlation between height and CAC score was 0.60 and was significantly different than 0 (P = 0.024).

Conclusions

Further studies of shared genetic factors between height and CAC may provide important insight into the complex genetic architecture of CHD, in part through increased understanding of the molecular pathways underlying the process of both normal growth and disease development. Bivariate genetic linkage analysis may provide a powerful mechanism for identifying specific genomic regions associated with both height and CAC.     

颈动脉内中膜厚度及斑块与冠心病的相关性

目的探讨颈动脉内中膜厚度(IMT)及斑块与冠状动脉造影(CAG)结果的相关性,了解IMT在预测冠心病方面的价值。方法研究对象116名经CAG分为冠心病组和非冠心病组,超声观察颈动脉IMT及有无斑块形成并与CAG结果比较。结果非冠心病组与冠心病组比较患者颈动脉IMT、斑块指数均存在显著性差异(P<0．01),颈动脉IMT与冠状动脉狭窄程度呈正相关(r= 0．634,P<0．01)。颈动脉IMT对冠心病诊断有较高的敏感性及特异性。结论颈动脉超声可能是冠心病诊断的一项重要的辅助检查手段。     

脉搏波传导速度和踝臂指数对冠心病的诊断价值

目的探讨脉搏波传导速度（pulse wave velocity,Pwv）、踝臂指数（ankle brachial index,ABI）对冠状动脉粥样硬化性心脏病（冠心病）冠状动脉（冠脉）狭窄严重程度的诊断价值,分析Pwv及动脉内膜中层厚度（inteima-media thickness,IMT）对于筛选冠心病的敏感性与特异性。方法应用无创动脉硬化检测仪和彩色多普勒超声机收集体检及住院疑似冠心病的132例患者的血管功能性指标PWV、ABI及结构性指标IMT,同时对这些患者行冠脉造影检查,按照冠脉造影结果将患者分为冠脉正常组及冠心病组。按照冠脉造影结果又将冠心病组分为单支病变组、两支病变、多支病变组。按照分组对检查结果进行相关性分析并观察PWV、IMT对于筛选冠心病的灵敏性与特异性。结果冠心病组Pwv显著高于冠脉正常组,差异有统计学意义（1756．07±314．30vs1385．98±109．92,t=-8．994,P〈0．001）：冠心病组ABI低于冠脉正常组,差异有统计学意义（1．06±0．13vs1．19±0．07,t=6．011,P〈0．001）。PWV对于筛选冠心病的敏感性为66．19％、特异性为96％;IMT对于筛选冠心病的敏感性为50．72％、特异性为75％。结论Pwv、ABI对于评价冠心病冠脉病变的严重程度有很好的诊断价值：Pwv比IMT对于冠心病的筛选具有更重要的临床意义。     

Comparative performance of subclinical atherosclerosis tests in predicting coronary heart disease in asymptomatic individuals.

The prognostic performance of subclinical atherosclerosis in predicting coronary heart disease (CHD) needs to be clarified because of the existence of many non-invasive tests available for its detection in the clinical setting: ultrasound measurement of carotid intima-media thickness (IMT) and plaque, cardiac computed tomography assessment of coronary artery calcium, Doppler stethoscope measurement of ankle-arm index pressure (AAI), and mechanographic or Doppler determination of aortic pulse wave velocity (PWV). Data analysis of the main prospective studies in asymptomatic populations allows the establishment of a dose-response relationship between subclinical atherosclerosis burden and cumulative incidence of future CHD event (absolute risk). Negative subclinical atherosclerosis testing conveys a low 10-year CHD risk inferior to 10% whatever the test considered, i.e. IMT less than the 1st tertile or 1st quintile, AAI > or = 0.90, PWV less than the first tertile, no discernible carotid plaque, or zero coronary calcium score. Positive testing for IMT (>95th percentile or 5th quintile), AAI (<0.90), or PWV (>3rd tertile) conveys a moderately high 10-year CHD risk between 10 and 20%. Positive testing for carotid plaque (focal protrusion >1.5 mm or mineralization) or coronary calcium (total score >300 or 400 units) conveys a high 10-year CHD risk superior to 20%. Therefore, positive subclinical atherosclerosis measurement seems to have its place in the context of existing prediction models, namely for intermediate risk classification. It also remains to be established whether individuals with negative subclinical atherosclerosis may be considered at low CHD risk and receive conservative management.     

No correlation and low agreement of imaging and inflammatory atherosclerosis' markers in familial hypercholesterolemia

Our purpose was to study the determinants of coronary and carotid subclinical atherosclerosis, aortic stiffness and their relation with inflammatory biomarkers in familial hypercholesterolemia (FH) subjects. Furthermore, we evaluated the agreement degree of imaging and inflammatory markers’ severity used for coronary heart disease (CHD) prediction. Coronary calcium scores (CCS), carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV), C reactive protein (CRP) and white blood cells count (WBC) were determined in 89 FH patients (39 ± 14 years, mean LDL-C = 279 mg/dl) and in 31 normal subjects (NL). The following values were considered as imaging and biomarkers’ severity: CCS > 75th% for age and sex, IMT > 900 μm, PWV > 12 m/s, and CRP > 3 mg/l.Coronary artery calcification (CAC) prevalence and severity, IMT, PWV and WBC values were higher in FH than in NL (all parameters, p < 0.05). After multivariate analysis, the following variables were considered independent determinants of (1) IMT: systolic blood pressure, 10-year CHD risk by Framingham risk scores (FRS) and apolipoprotein B (r² = 0.33); (2) PWV: age (r² = 0.35); (3) CAC as a continuous variable: male gender and LDL-cholesterol year score (LYS) (r² = 0.32); (4) presence of CAC as dichotomous variable: FRS (p = 0.0027) and LYS (p = 0.0228). With the exception of a moderate agreement degree between IMT and PWV severity (kappa = 0.5) all other markers had only a slight agreement level (kappa < 0.1). In conclusion, clinical parameters poorly explained IMT, CAC and PWV variability in FH subjects. Furthermore, imaging markers and inflammatory biomarkers presented a poor agreement degree of their severity for CHD prediction.     

颈动脉多普勒超声与心绞痛患者冠状动脉病变的关系

目的采用彩色多普勒超声仪分析心绞痛患者颈动脉病变,探讨其在冠状动脉病变中的临床诊断价值。方法选择因心绞痛行冠状动脉造影的住院患者328例,根据冠状动脉造影结果分为4组:对照组(80例)、单支病变组(102例)、2支病变组(62例)和多支病变组(84例)。用彩色多普勒超声仪测量颈总动脉内膜中层厚度(intimamediathickness,IMT)及颈动脉分叉处IMT,记录颈动脉斑块的位置、数量。结果与对照组比较,2支病变组分叉处IMT和斑块积分明显增高,多支病变组颈总动脉IMT、分叉处IMT和斑块积分明显增高,差异有统计学意义(P0.05,P0.01)。与对照组比较,多支病变组颈总动脉IMT增厚比例明显增高,差异有统计学意义(P0.05);与单支病变组比较,多支病变组颈总动脉IMT增厚比例明显增高,差异有统计学意义(P0.05)。糖尿病是冠状动脉病变的主要危险因素(OR=2.8,95% CI:1.18～6.63)。结论颈动脉粥样硬化与冠状动脉病变有相关性,采用彩色多普勒超声分析颈动脉病变情况,对冠心病患者具有较好的筛查及预测价值。     

Eosinophil count is positively correlated with coronary artery calcification

Recent studies suggested that allergic disorders and increased eosinophil count were associated with atherosclerosis. The purpose of this study was to assess the relationship between eosinophil count and coronary artery calcification (CAC). We performed a cross-sectional study in 1363 consecutive participants with clinical suspicion of coronary heart disease (CHD). We evaluated the relationships between CAC score determined by multislice CT and peripheral eosinophil count as well as major cardiovascular risk factors, including age, body mass index, smoking status, hypertension, dyslipidemia, diabetes mellitus (DM), high-sensitivity C-reactive protein and estimated glomerular filtration rate (eGFR). Sex (P=0.0004), hypertension (P=0.0002), dyslipidemia (P=0.0004) and DM (P=0.0061) were associated with log(CAC+1), respectively. Positive correlations were found between log(CAC+1), and age (r=0.325, P<0.0001) and eosinophil count (r=0.165, P<0.0001). Negative correlations were found between log(CAC+1) and eGFR (r=-0.166, P<0.0001). Multivariate linear regression analysis demonstrated that age (β=0.314, P<0.0001), sex (β=0.124, P<0.0001), hypertension (β=0.084, P=0.0008), DM (β=0.108, P<0.0001), eGFR (β=-0.079, P=0.0021) and eosinophil count (β=0.147, P<0.0001) were independent determinants of log(CAC+1). In conclusion, eosinophil count correlated positively with CAC in participants with clinical suspicion of CHD.     

冠心病患者冠状动脉粥样硬化程度与颈动脉粥样硬化的相关性研究

目的 探讨冠心病患者颈动脉粥样硬化与冠状动脉硬化程度之间的关系.方法 选取2012年1月至2013年6月河北大学附属医院心内科治疗的冠心病患者350例,依据冠状动脉造影结果将患者分为冠心病组和非冠心病组,其中冠心病组260例,非冠心病组90例;依据造影结果将冠心病组患者进行再次分组,其中单支病变组113例,双支病变组89例,三支病变组58例.比较冠心病组及非冠心病组间及不同冠状动脉病变支数三组间的颈动脉内-中膜厚度（IMT）、斑块积分及Gensini评分;统计分析冠状动脉病变支数与以上观察指标的相关性.结果 冠心病组的颈动脉IMT、斑块积分、Gensini积分分别为（1.37±0.23）、（5.37±3.98）、（23.32±7.33）,均高于非冠心病组,两组间比较差异有统计学意义（P＜0.05）.双支病变组和三支病变组的斑块检出率为79.8％和81.0％,双支病变组及三支病变组患者颈动脉IMT分别为（1.31±0.21）mm和（1.37±0.27）mm,双支病变组和三支病变组患者的斑块检出率与颈动脉IMT值均高于单支病变组,三组间比较差异有统计学意义（P＜0.05）.冠状动脉病变支数与IMT、颈动脉斑块积分呈显著正相关;Gensini评分与IMT及颈动脉斑块积分呈显著正相关.结论 冠状动脉的粥样硬化程度随着患者的颈动脉粥样硬化程度的升高而加重,冠心病的严重程度可以通过颈动脉超声检测反映出来.     

Distribution of coronary atherosclerosis in patients with coronary artery disease

The distribution of coronary atherosclerosis has not been fully clarified. We measured coronary artery calcium score (CACS) in 624 consecutive patients for the right coronary artery (RCA), left main trunk (LMT), left anterior descending coronary artery (LAD), and left circumflex coronary artery (LCx), then calculated total CACS. Coronary artery calcium score was measured using the Agatston method. We divided these patients into four groups: CACS 1–100 (Group A, n = 267), CACS 101–400 (Group B, n = 160), CACS 401–1000 (Group C, n = 110), and CACS >1000 (Group D, n = 87). In Group A, B, and C, the CACS in LAD was significantly higher than in the other three arteries (P < 0.0001). In Group D, the CACS was not significantly different between LAD and RCA (P = 0.6930). In Groups A, B, and C, coronary artery calcium (CAC) was more frequently found in LAD compared with other arteries (P < 0.0001). However, in Group D the prevalence of CAC was not significantly different among the three arteries (P = 0.4435). Coronary artery calcium was found more frequently in LAD than in the other coronary arteries in patients with mild to high CAC, but not in those with very high CAC.     

冠心病患者冠状动脉病变血管数与高敏C反应蛋白、颈动脉斑块分级和内皮功能的相关性

目的探讨冠心病患者冠状动脉病变血管数与高敏C反应蛋白(hsCRP)、内皮依赖血管舒张功能、颈动脉内膜中层厚度(IMT)和斑块积分的相关性。方法采用高分辨率血管超声法检测76例冠心病患者与30例非冠心病对照组肱动脉血流介导的内皮依赖性血管舒张功能(FMD)、颈动脉IMT及斑块积分;并检测患者血液中hsCRP水平,对冠心病患者进行冠状动脉造影,根据冠状动脉病变血管数将冠心病患者分为3组:单支病变组、双支病变组及三支病变组。结果冠心病患者的血浆hsCRP显著高于对照组,FMD在冠心病各亚组中明显降低,与对照组比较差异有统计学意义(均为P<0.05);IMT在冠心病组中明显增厚,与对照组比较差异有统计学意义(均为P<0.05);颈动脉斑块积分在冠心病各亚组间比较差异有统计学意义(P<0.05)。冠心病患者冠状动脉病变血管数与血浆hsCRP及斑块积分呈正相关,与FMD呈负相关。结论血浆hsCRP、FMD及颈动脉斑块积分的检测与冠心病患者冠状动脉病变支数相关。     

Assessment by cardiovascular magnetic resonance, electron beam computed tomography, and carotid ultrasonography of the distribution of subclinical atherosclerosis across Framingham risk strata

Screening for subclinical atherosclerosis has been advocated for individuals at intermediate global risk for coronary heart disease (CHD). However, the distribution of subclinical atherosclerosis test values across CHD risk strata is unknown. We studied a stratified random sample of 292 participants (mean age 59.5 years, 50% women) from the offspring cohort of the Framingham Heart Study who were free of clinically apparent cardiovascular disease. We assessed abdominal and thoracic aortic plaque burden by cardiovascular magnetic resonance (CMR), coronary artery calcification (CAC) and thoracic aortic calcification (TAC) by electron beam computed tomography, and common carotid intima-media thickness (C-IMT) by ultrasonography. We categorized the upper 20% of each measurement as a high level of atherosclerosis and evaluated these variables across clinically relevant Framingham CHD risk score strata (low, intermediate, and high risk). In age-adjusted analyses in men and women, correlations across CMR aortic plaque, CAC, TAC, and C-IMT were low (maximum r = 0.30 for CAC:TAC in women, p <0.005). In men and women, the proportion of subjects with high atherosclerosis test results for any of these measurements increased significantly across Framingham CHD risk score strata (Kruskal-Wallis test, p <0.0001). In the intermediate Framingham CHD risk score category, 14% of men and 25% of women had a high atherosclerosis result on >or=2 measurements. However, different participants were identified as having high atherosclerosis by each modality. For example, in a comparison of the overlap across CMR aortic plaque, CAC, and C-IMT, only 4% of men and 16% of women were classified as having high atherosclerosis on all 3 measurements. In conclusion, in a community-based sample, correlations among subclinical atherosclerosis test results are low, and a substantial proportion has high levels of subclinical atherosclerosis detected on >or=2 imaging tests.     

Clinical significance of the coronary calcification score by multidetector row computed tomography for the evaluation of coronary stenosis in Japanese patients.

BACKGROUND: The coronary artery calcification (CAC) score measured by multidetector row computed tomography (MDCT) has emerged as a marker for predicting coronary artery disease (CAD). To evaluate the clinical significance of the CAC score, coronary artery stenosis as assessed by coronary angiography (CAG) was compared with the CAC score determined by MDCT, risk factors and medications. METHODS AND RESULTS: Subjects included 374 consecutive patients who underwent ECG-gate CT angiography using MDCT. The accuracy in patients with a CAC score >or=400 was 84%, and significantly lower than that in patients with a CAC score =0. In addition 92 patients (68 males, 24 females; mean age, 63+/-11 years) who underwent both MDCT and CAG within a 1-month period were selected for further investigation. Patients with significant coronary stenosis had a significantly higher CAC score than those without stenosis. In addition, a higher number of stenosed vessels was associated with a higher CAC score. The subjects were divided into 3 groups according to the CAC score: low (0-12), intermediate (13-444) and high (>or=445). The CAC score was significantly associated with age, and plasma levels of total cholesterol and hemoglobinA1c, and logistic regression analysis revealed that significant coronary stenosis as assessed by CAG was most closely correlated with the CAC score (p=0.03). CONCLUSIONS: The CAC score determined by MDCT can predict CAD independent of other factors, such as age, metabolic diseases and medications, when coronary stenosis can not be diagnosed because of severe calcification.     

Coronary artery calcium versus intima-media thickness as a measure of cardiovascular disease among asymptomatic adults (from the Rancho Bernardo Study)

Detection and quantification of subclinical coronary heart disease by noninvasive imaging techniques offers the potential for earlier diagnosis with targeted prevention and therapy. This study, designed to determine the extent to which carotid artery intima-media thickness (IMT) predicts coronary artery calcium (CAC) in asymptomatic older adults, included 141 men and 137 women > or =55 years of age with no previous coronary heart disease who had B-mode ultrasound of the common and/or internal carotid arteries in 1997 to 1999 to measure IMT and electron beam computed tomographic scanning in 2001 to 2002 to measure CAC score. Overall, 29% of participants had a severe plaque burden (CAC score >400); 50% of these had a CAC score >800. IMT of the common and internal carotid arteries was significantly associated with the CAC score measured an average of 3 years later. The ability to correctly identify subjects with a severe CAC score (sensitivity) was 50% to 60% for an IMT of the internal or common carotid artery > 80th percentile (internal carotid IMT > or =1.9 mm and common carotid IMT > or =1.04 mm). Specificity, the ability to correctly identify those who did not have a severe CAC score (> or =400), was approximately 75%. In conclusion, IMT of the carotid arteries predicted the severity of CAC burden an average of 3 years later in community-dwelling asymptomatic older adults.     

Assessment of coronary artery calcification in hemodialysis patients using multi-detector spiral CT scan.

Cardiovascular disease in association with coronary artery calcification (CAC) is the leading cause of death in patients with end-stage renal disease (ESRD). The evaluation of CAC has been performed by electron beam CT scan. The purpose of the present study was to assess CAC using multi-detector spiral CT (MDCT) and to evaluate contributors to CAC in these patients. Fifty-three patients on chronic hemodialysis participated in this study. Their mean age was 61.0+/-9.6 years, and the mean duration of dialysis therapy was 6.7+/-5.4 years. We used an automatic device to measure arterial pulse wave velocity (PWV) as an index of arterial wall stiffness. The aortic calcification index (ACI) was quantified morphometrically by CT scan. The CAC score correlated positively with ACI score (r =0.863, p <0.0001). Linear regression analysis indicated that the CAC scores correlated positively with age (r =0.406, p =0.0023), C-reactive protein (r =0.38, p =0.0047) and PWV (r =0.303, p =0.0271). Stepwise regression analysis indicated that ACI (beta-coefficient=0.862, p <0.0001) and arterial PWV (beta-coefficient=0.303, p <0.0001) were independently associated with CAC score. The mean CAC score of patients with cardiac events (2,568.5+/-2,575.1 mm3) was significantly higher than that (258.0+/-409.2 mm3) of patients without cardiac events. In conclusion, our results showed clearly that assessment of CAC score using MDCT may be predictive for detecting the presence of coronary artery disease. CAC is indirectly associated with increased arterial stiffness and the extent of aortic calcification in hemodialysis patients. We did not find a significant correlation between CAC score and parameters of mineral metabolism, including serum levels of calcium, phosphorus and parathyroid hormone. A longitudinal prospective study is required to assess the predictive value of this technique in determining cardiac events in large numbers of hemodialysis patients.