Correlation and predictive value of aortic root calcification markers with coronary artery calcification and obstructive coronary artery disease

Objective

To evaluate the correlation between aortic root calcification (ARC) markers and coronary artery calcification (CAC) derived from coronary artery calcium scoring (CACS) and their ability to predict obstructive coronary artery disease (CAD).

Methods

We retrospectively analyzed 189 patients (47% male, age 60.3 ± 11.1 years) with an intermediate probability of CAD who underwent clinically indicated CACS and coronary CT angiography (CCTA). ARC markers [aortic root calcium score (ARCS) and volume (ARCV)] were calculated and compared to CAC markers: coronary artery calcium score (CACS), volume (CACV), and mass (CACM). CCTA datasets were visually evaluated for significant CAD (stenosis ≥ 50%) and the ability of ARC markers to predict obstructive CAD was assessed.

Results

ARCS (mean 67.7 ± 189.5) and ARCV (mean 67.3 ± 184.7) showed significant differences between patients with and without CAC (109.4 ± 238.6 vs 9.42 ± 31.4, p < 0.0001; 108.5 ± 232.4 vs 9.9 ± 30.5, p < 0.0001). A strong correlation was found for ARCS and ARCV with CACS, CACM, and CACV (all p < 0.0001). In a multivariate analysis, ARCS (OR 1.09, p = 0.033) and ARCV (OR 1.12, p = 0.046) were independent markers for CAC. Using a receiver-operating characteristics analysis, the AUC to detect severe CAC was 0.71 (p < 0.0001) and 0.71 (p < 0.0001) for ARCS and ARCV, respectively. ARCS (0.67, p < 0.0001) and ARCV (0.68, p < 0.0001) showed discriminatory power for predicting obstructive CAD, yielding sensitivities 61 and 78% and specificities of 62 and 80%, respectively.

Conclusion

ARC markers are associated with and independently predict the presence of CAC and obstructive CAD. Further testing is required in patients with severe ARC and significant CAD in order to reliably obtain these markers from thoracic-CT or X-ray for proper risk classification.

     

Usefulness of cinefluoroscopic detection of coronary artery calcification in the diagnostic work-up of coronary artery disease

Aim: To determine in which patients (cine)fluoroscopic detection of coronary artery calcifications is recommended for the diagnosis of coronary artery disease and the consequence of this finding for referral for cinecoronary arteriography. Materials and methods: Data were retrospectively obtained from 778 patients who had been referred for cinecoronary arteriography. Excluded were patients with a previous myocardial infarction, a previous abnormal cinecoronary arteriogram and patients with unstable angina. The discriminating value was assessed with the help of the crude likelihood ratio (LR), as well as the LRs stratified for gender, age and symptomatology. The gold standard was the coronary arteriogram. Furthermore, the post-test probability was estimated using logistic regression to take dependence on age, sex and symptomatology into account. Results: The crude LR of a positive and negative test result, with 95% confidence intervals, was, respectively 5.8 (4.1–8.2) and 0.52 (0.47–0.58), but was dependent on the clinical variables. Estimated probabilities of having coronary artery disease (CAD) varied substantially for a negative as well as a positive test result with the categories of clinical variables. Conclusion: (Cine)fluoroscopy discriminates between patients with and without disease; the test proved to be especially useful in females with atypical angina and patients of both sexes with non-specific chest pain.     

Effect of CT digital image compression on detection of coronary artery calcification

Purpose: To test the effect of digital compression of CT images on the detection of small linear or spotted high attenuation lesions such as coronary artery calcification (CAC).Material and Methods: Fifty cases with and 50 without CAC were randomly selected from a population that had undergone spiral CT of the thorax for screening lung cancer. CT image data were compressed using JPEG (Joint Photographic Experts Group) or wavelet algorithms at ratios of 10:1, 20:1 or 40:1. Five radiologists reviewed the uncompressed and compressed images on a cathode-ray-tube. Observer performance was evaluated with receiver operating characteristic analysis.Results: CT images compressed at a ratio as high as 20:1 were acceptable for primary diagnosis of CAC. There was no significant difference in the detection accuracy for CAC between JPEG and wavelet algorithms at the compression ratios up to 20:1. CT images were more vulnerable to image blurring on the wavelet compression at relatively lower ratios, and "blocking" artifacts occurred on the JPEG compression at relatively higher ratios.Conclusion: JPEG and wavelet algorithms allow compression of CT images without compromising their diagnostic value at ratios up to 20:1 in detecting small linear or spotted high attenuation lesions such as CAC, and there was no difference between the two algorithms in diagnostic accuracy.     

心肌灌注显像联合冠状动脉钙化积分诊断冠心病的价值及最新进展

心肌灌注显像（MPI）在冠心病的诊断、危险度分层及预后评价中扮演着越来越重要的角色，冠状动脉钙化积分（CACS）可协助对冠心病患者进行进一步的危险度分层，但两者有各自的局限性和不足。将两者联合应用可以相互弥补不足，为临床提供更多的信息。行SPECT/CT心肌灌注显像时，需进行衰减矫正CT（CTAC）扫描，若采用心电门控的呼气末屏气螺旋CT扫描，则在用于MPI衰减矫正的同时又可用于CACS测定，实现一站式检查，在减少患者辐射剂量的同时又可为临床提供更多的信息。笔者综述了CACS、MPI及两者联合应用的临床价值，并对一站式采集MPI与CACS的最新进展进行了综述。     

Influence of coronary dominance on coronary artery calcification burden

ObjectiveTo evaluate the influence of coronary artery dominance on observed coronary artery calcification burden in outpatients presenting for coronary computed tomography angiography (CCTA).MethodsA 12-month retrospective review was performed of all CCTAs at a single institution. Coronary arterial dominance, Agatston score and presence or absence of cardiovascular risk factors including hypertension (HTN), hyperlipidemia (HLD), diabetes and smoking were recorded. Dominance groups were compared in terms of calcium score adjusted for covariates using analysis of covariance based on ranks. Only covariates observed to be significant independent predictors of the relevant outcome were included in each analysis. All statistical tests were conducted at the two-sided 5% significance level.Results1223 individuals, 618 women and 605 men were included, mean age 60 years (24–93 years). Right coronary dominance was observed in 91.7% (n = 1109), left dominance in 8% (n = 98), and codominance in 1.3% (n = 16). The distribution of patients among Agatston score severity categories significantly differed between codominant and left (p = 0.008), and codominant and right (p = 0.022) groups, with higher prevalence of either zero or severe CAC in the codominant patients. There was no significant difference in Agatston score between dominance groups. In the subset of individuals with coronary artery calcification, Agatston score was significantly higher in codominant versus left dominant patients (mean Agatston score 595 ± 520 vs. mean 289 ± 607, respectively; p = 0.049), with a trend towards higher scores in comparison to the right-dominant group (p = 0.093). Significance was not maintained upon adjustment for covariates.ConclusionsWhile the distribution of Agatston score severity categories differed in codominant versus right- or left-dominant patients, there was no significant difference in Agatston score based on coronary dominance pattern in our cohort. Reporting and inclusion of codominant subsets in larger investigations may elucidate whether codominant anatomy is associated with differing risk.     

Comparison of the diagnostic value of cinefluoroscopy and simple fluoroscopy in the detection of calcification in coronary arteries

Aim: Comparison of the diagnostic value of cinefluoroscopy and simple fluoroscopy in the detection of calcification in coronary arteries. Patients and methods: Data were prospectively obtained from 143 patients in whom simple fluoroscopy as well as cinecoronary arteriography were performed. Excluded were patients with a previous myocardial infarction, a previous abnormal cinecoronary arteriogram and patients with unstable angina. With the coronary arteriogram as the gold standard, the likelihood ratios (LR) of simple fluoroscopy were determined, mismatches with cinefluoroscopy were analysed and Kappa, as a measure for inter-test agreement, was calculated. Results: The LRs with 95% confidence intervals for a positive and negative result were 5.3 (2.6–11.0) and 0.43 (0.28–0.69), respectively. There was a mismatch in 12 (8.3%) patients. Kappa with a 95% confidence interval was 0.90 (0.73–1.0). Conclusions: Both test modalities are almost identical and conclusions with respect of the diagnostic value of cinefluoroscopy also holds for simple fluoroscopy.     

Coronary artery calcification detected with ultrafast CT as an indication of coronary artery disease.

To assess the relationship of coronary artery calcification to angiographically detectable disease, the authors evaluated 100 patients less than 60 years of age who underwent clinically indicated coronary angiography and ultrafast computed tomography (CT). The ultrafast CT technique consisted of 3-mm-thick contiguous sections and a 100-msec acquisition time. All patients with clinically significant disease at angiography (defined as at least one stenosis with a diameter narrowing of at least 50%) had some coronary artery calcification present at ultrafast CT (100% sensitivity in this population). The absence of calcification at ultrafast CT had a 100% negative predictive value for clinically significant coronary artery disease. Specificity and positive predictive value were 47% and 62%, respectively. Sensitivity and specificity of ultrafast CT in the detection of patients with angiographically detectable disease were 94% and 72%, respectively. Ultrafast CT of the heart is an anatomically based, noninvasive test with high sensitivity for the detection of coronary artery calcification. Ultrafast CT may be beneficial in the screening of selected populations for the presence of atherosclerotic coronary disease.     

Imaging of coronary artery calcification. Its importance in assessing atherosclerotic disease

Coronary artery calcification is a marker for atherosclerotic disease. The calcifications frequently occur early in the disease process and often before the development of luminal narrowing or cardiac events. Electron beam CT has a high accuracy in detecting calcifications, and thus has prognostic value in predicting luminal narrowing and future cardiac events.     

Evaluation of coronary artery calcification by ultrafast CT]

A preliminary study was performed to determine whether ultrafast computed tomography (UFCT) is useful as a noninvasive screening examination for predicting coronary artery disease (CAD). UFCT was used to detect coronary artery calcification in 31 patients with angina pectoris (AP) without myocardial infarction. Except for six patients with vasospastic AP, 22 out of 25 patients had detectable calcification in at least one vessel. SVD, DVD and TVD were detected in six of nine patients (67%), seven of seven (100%) and nine of nine (100%), respectively. Based on the findings of coronary calcification by UFCT, the sensitivity, specificity and predictive accuracy of angiographically significant stenosis (greater than 75%) were 94%, 71% and 78% for all branches, respectively. The calcification score for vessels with significant stenotic lesion (n = 48) was statistically higher (p less than 0.01) than that for vessels without stenotic lesion (n = 45). In conclusion, UFCT appears to be useful noninvasive screening examination for detecting CAD, although a prospective study in a large number of patients will be necessary to establish the value of this new method more reliably.     

Severe aortic arch calcification depicted on chest radiography strongly suggests coronary artery calcification

Objective

To evaluate the association between aortic arch calcifications (AAC) on chest radiography and coronary artery calcium (CAC) score determined by CT.

Methods

A total of 128 patients (75 men; 69.3?±?14.7 years) who underwent chest radiography and CAC scoring at CT were included in this retrospective analysis. The extent of AAC on chest radiography was evaluated independently by two blinded observers using a semi-quantitative four-point scale (0–3). Intra- and interobserver agreement was assessed by weighted ? statistics. Amount of AAC determined on radiography was correlated with CAC and ROC analyses performed to characterise the diagnostic performance of AAC grading.

Results

Excellent intraobserver (??=?0.82) and good interobserver (??=?0.75) agreement of AAC grading was noted. Moderate agreement (??=?0.46, 95 % CI 0.36–0.56) with a linear trend (P?<?0.0001) between AAC grades and CAC scores was found. Cut-off between AAC grades 0–2 and 3 had a sensitivity of 38.6 %, specificity of 96.4 %, PPV of 85.0 %, NPV of 75.0 % and accuracy of 76.6 % for the correct identification of CAC scores greater than 400.

Conclusion

Semi-quantitative AAC grading on chest radiography is reliable and positively associated with CAC scoring. We propose to report the extent of AAC in comprehensive radiological reports as “not present”, “moderate” or “severe”, as severe AAC strongly suggests coronary artery calcification.

Key Points

? Semi-quantitative aortic arch calcification (AAC) grading on plain chest radiography appears reliable. ? AAC grading is positively associated with CT coronary artery calcium scoring. ? AAC grading has a high specificity for ruling out CAC scores greater than 400. ? We propose the reporting of the extent of AAC grade in chest X-ray (CXR) reports.     

钙化对FFR CT诊断冠状动脉疾病准确性影响的研究

目的研究钙化对冠状动脉CT血管成像(CCTA)测定的血流储备分数(FFR_(CT))诊断冠状动脉疾病准确性的影响。方法回顾性分析行CCTA检查和有创FFR检查的38例病人共50支血管的资料。用Agatston积分法测量50支血管的钙化积分值,以钙化积分值100为阈值,分为A1组(≤100)和A2组(100)。利用c FFR软件进行FFR_(CT)值测定,FFR及FFR_(CT)0.8定义为病变特异性心肌缺血。采用组内相关系数(ICC)计算总体及A1、A2组FFR_(CT)与FFR的一致性。以有创FFR作为参考标准,以血管为分析单位,分别计算总体及A1、A2两组FFR_(CT)的诊断准确度、敏感度、特异度、阳性预测值及阴性预测值,并采用Fisher确切概率法比较2组间的差异。结果总体FFR_(CT)和FFR的ICC系数为0.771(95%CI:0.597~0.870),A1组FFR_(CT)和FFR的ICC为0.819(95%CI:0.633~0.910),A2组FFR_(CT)和FFR的ICC为0.649(95%CI:0.032~0.873)。总体FFR_(CT)诊断敏感度、特异度、准确度、阳性预测值及阴性预测值分别为90.9%、97.4%、96.0%、90.9%、97.4%;A1组和A2组FFR_(CT)诊断敏感度、特异度、准确度、阳性预测值及阴性预测值分别为85.7%、100%、96.9%、100%、96.0%和100%、92.3%、94.1%、80.0%、100%;A1和A2组间诊断效能各指标的差异均无统计学意义(均P0.05)。结论 FFR_(CT)与FFR在冠状动脉狭窄血流评估方面有较好的一致性,研究未显示钙化影响FFR_(CT)的诊断效能。     

多层螺旋CT无创性冠状动脉造影对冠状动脉疾病的诊断价值

目的:探讨16层螺旋CT冠状动脉造影对冠状动脉病变的临床诊断价值。方法:57例疑似冠状动脉病变的患者行16排螺旋CT检查和冠状动脉造影,不包括5例为冠状动脉支架置入术后(支架12个)。将冠状动脉分为13个节段,分析所有管腔大于2mm的节段,评价图像是否能满足管腔评价。管腔狭窄大于50%认为有意义,以常规冠状动脉造影作为金标准,比较16层螺旋CT在诊断有意义的冠状动脉狭窄方面的敏感性、特异性、阳性预测值、阴性预测值。结果:在所有638个节段中,588个节段(占92.16%)能够满足冠状动脉管腔评价。对于16层螺旋CT能够显示有意义冠状动脉狭窄,与ICA相对照,若以动脉节段计数,MSCT显示中度以上狭窄的敏感性、特异性、阳性预测值、阴性预测值和准确度分别为93.61%、91.11%、89.79%、98.12%和94.63%。以动脉主干计数,MSCT显示中度以上狭窄的敏感性、特异性、阳性预测值、阴性预测值和准确度分别为92.82、、91.31%、80.43%、97.37%和82.08%。以患者计数,MSCT显示中度以上狭窄的敏感性、特异性、阳性预测值、阴性预测值和准确度分别为94.73%、90.00%、93.01%、92.99%和82.75%。结论:16层螺旋CT结合回顾性心电门控技术冠状动脉成像无创、简单易行。既能显示管腔情况又能显示冠脉管壁,弥补了ICA的不足;经严格控制影响因素,具有较高的敏感性和特异性,较高的阴性预测值可避免不必要的有创性检查。对支架术后的随访也有较高的应用价值,对血管变异的显示直观确切。可作为一种有效的筛查和随访手段应用于临床。