Prevalence and Prognosis of Nonobstructive Coronary Artery Disease in Patients Undergoing Coronary Angiography or Coronary Computed Tomography Angiography: A Meta-Analysis

Objective

To evaluate the prevalence, clinical characteristics, and risk of cardiac events in patients with nonobstructive coronary artery disease (CAD).

Role of MDCT in evaluation of epicardial fat volume as an independent risk factor for coronary atherosclerosis

Objective

The aim of this study was to clarify the association between epicardial fat volume and coronary atherosclerosis.

冠状动脉CT造影在2型糖尿病合并冠心病患者诊断中的应用价值研究

目的:探讨冠状动脉CT造影(CCTA)在2型糖尿病合并冠心病(CHD)患者诊断中的应用价值.方法:选取126例2型糖尿病疑似合并CHD患者,分别进行常规心电图和CCTA检查.以冠状动脉血管造影(CAG)为标准,对比两种检查方法诊断结果的准确性.结果:经CAG检查和诊断分析,126例2型糖尿病患者诊断为CHD阳性71例,...     

Hypertrophic Cardiomyopathy (HCM): New insights into Coronary artery remodelling and ischemia from FFRCT

IntroductionAngina, myocardial ischemia, and coronary artery physiology in hypertrophic cardiomyopathy (HCM) are poorly understood. However, coronary computed tomography angiography (CCTA) with fractional flow reserve from CT (FFRCT) analysis offers a non-invasive method for evaluation of coronary artery volume to myocardial mass ratio (V/M) that may provide insight into such mechanisms. Thus, we sought to investigate changes in V/M in HCM.MethodsA retrospective analysis was performed on 37 HCM patients and 37 controls matched for age, sex, and cardiovascular risk factors; CCTA-derived coronary artery lumen volume (V) and myocardial mass (M) were used to determine V/M. FFR_CT values were calculated for the left anterior descending (LAD), left circumflex (LCx) and right coronary (RCA) arteries as well as the 3-vessel cumulative FFR_CT values.ResultsHCM patients had significantly increased myocardial mass (176 ± 84 vs. 119 ± 27 g, p < 0.0001) and total coronary artery luminal volume (4112 ± 1139 vs. 3290 ± 924 mm³, p < 0.0001) that resulted from increases in segmented luminal volumes of both the left and right coronary artery systems. However, HCM patients had significantly decreased V/M (23.8 ± 5.9 vs. 26.5 ± 5.3 mm³/g; p = 0.026) which was further decreased when restricting V/M analysis to those HCM patients with septal hypertrophy (22.4 mm³/g, p = 0.01) that was mild-moderately predictive of HCM (AUC = 0.68). HCM patients also showed significantly lower nadir FFR_CT values in the LCx (0.87 ± 0.06 vs. 0.91 ± 0.06, p = 0.02), and cumulative 3-vessel FFR_CT values (2.58 ± 0.18 vs. 2.63 ± 0.14, p = 0.006).ConclusionsHCM patients demonstrate significantly greater coronary volume. Despite this, HCM patients suffer from decreased V/M. Further prospective studies evaluating the relationship between V/M, angina, and heart failure in HCM are needed.     

High-pitch coronary CT angiography in dual-source CT during free breathing vs. breath holding in patients with low heart rates

Background

Coronary CT angiography (CCTA) is usually performed during breath holding to reduce motion artifacts caused by respiration. However, some patients are not able to follow the breathing commands adequately due to deafness, hearing impairment, agitation or pulmonary diseases. The aim of this study was to evaluate the potential of high-pitch CCTA in free breathing patients when compared to breath holding patients.

Methods

In this study we evaluated 40 patients (20 free breathing and 20 breath holding patients) with a heart rate of 60 bpm or below referred for CCTA who were examined on a 2nd generation dual-source CT system. Image quality of each coronary artery segment was rated using a 4-point grading scale (1: non diagnostic–4: excellent).

Results

Mean heart rate during image acquisition was 52 ±5 bpm in both groups. There was no significant difference in mean image quality, slightly favoring image acquisition during breath holding (mean image quality score 3.76 ± 0.32 in breath holding patients vs. 3.61 ± 0.45 in free breathing patients; p = 0.411). Due to a smaller amount of injected contrast medium, there was a trend for signal intensity to be slightly lower in free breathing patients, but this was not statistically significant (435 ± 123 HU vs. 473 ± 117 HU; p = 0.648).

Conclusion

In patients with a low heart rate who are not able to hold their breath adequately, CCTA can also be acquired during free breathing without substantial loss of image quality when using a high pitch scan mode in 2nd generation dual-source CT.     

The Future of Cardiovascular Computed Tomography: Advanced Analytics and Clinical Insights

Cardiovascular computed tomography (CCT) has undergone rapid maturation over the last decade and is now of proven clinical utility in the diagnosis and management of coronary artery disease, in guiding structural heart disease intervention, and in the diagnosis and treatment of congenital heart disease. The next decade will undoubtedly witness further advances in hardware and advanced analytics that will potentially see an increasingly core role for CCT at the center of clinical cardiovascular practice. In coronary artery disease assessment this may be via improved hemodynamic adjudication, and shear stress analysis using computational flow dynamics, more accurate and robust plaque characterization with spectral or photon-counting CT, or advanced quantification of CT data via artificial intelligence, machine learning, and radiomics. In structural heart disease, CCT is already pivotal to procedural planning with adjudication of gradients before and following intervention, whereas in congenital heart disease CCT is already used to support clinical decision making from neonates to adults, often with minimal radiation dose. In both these areas the role of computational flow dynamics, advanced tissue printing, and image modelling has the potential to revolutionize the way these complex conditions are managed, and CCT is likely to become an increasingly critical enabler across the whole advancing field of cardiovascular medicine.     

320排CT超低管电压在体重指数≤30kg/m2患者冠状动脉血管成像中的应用

目的 通过与120kVp管电压冠状动脉CT血管成像方案对比,探讨在320排CT上应用70kV管电压、低对比剂用量、低对比剂流速的方案对正常体重指数（BMI≤30kg/m2）的患者行冠状动脉CT血管成像检查的可行性。方法 所有患者均采用宽体探测器CT行前瞻性心电门控轴扫模式采集数据。将52例患者随机分为两组：A组采用70kVp管电压以及低对比剂用量和流速;B组采用120kV管电压以及常规对比剂用量和流速。两组均采用混合迭代算法重建数据,统计患者的年龄、体重、BMI、心率、对比剂用量及流速等数据,测量冠脉各节段管腔内的CT值、SD值以及相邻胸壁脂肪组织的CT值与SD值,评估冠状动脉各节段血管的图像质量。采用独立样本t检验比较两组患者的客观指标;采用卡方检验比较两组图像的主观指标。结果 两组数据主观图像质量评分一致性评估为0.772,一致性较好。冠脉动脉主观评分差异无统计学意义（A组1.17±0.38,B组1.21±0.43,χ2=-0.958,P=0.338）。两组冠状动脉优良率为（100%与98.96%）,差异无统计学意义。两组患者在对比剂用量（A组27.15?3.70,B组48.92?5.08,t=-17.664,P=0.000）以及流速（A组2.71?0.37,B组4.50?0.35,t=-17.851,P=0.000）方面差异有统计学意义。两组患者吸收的辐射剂量差异有统计学意义（A组0.80±0.16,B组3.13±0.67,t=-17.282,P=0.000）。结论 70kV管电压在320排CT上对正常体重指数（BMI≤30kg/m2）患者行冠状动脉血管成像检查是可行的,在亚毫希弗条件下可获得满足临床诊断的图像,且较常规扫描方案大幅降低了碘对比剂用量以及注射速率。     

体质量对冠状动脉成像辐射剂量的影响

目的：探讨体质量指数(BMI)对螺旋CT冠状动脉血管成像(CCTA)辐射剂量的影响。方法对我院2013年3~5月收治的113例怀疑冠心病患者行CCTA,按不同BMI值分为三组,其中BMI<25的66例患者为A组,2530的6例患者为C组。采用回顾性心电门控,对不同组图像BMI和有效剂量进行比较。结果 A组、B组和C组患者的BMI值分别为(21.95±1.81)、(26.79±1.41)和(32.80±3.27),差异有显著统计学意义(F=166.53,P<0.01);A组、B组和C组的有效剂量分别为(14.28±2.46) mSv、(18.59±1.67) mSv和(21.72±3.06) mSv,差异有显著统计学意义(F=65.67,P<0.01);A组、B组和C组患者的图像质量评分分别为(3.96±0.10)分、(3.75±0.50)分和(3.66±0.81)分,差异无统计学意义(F=0.61,P>0.05)。结论在保证图像质量评分不变时,随着BMI值的增加,冠状动脉血管成像所得到的辐射剂量会增多。     

Prognostic Value of Computed Tomography-Derived Fractional Flow Reserve Comparison With Myocardial Perfusion Imaging

ObjectivesThe aim of this study was to compare the incremental prognostic value of coronary computed tomography (CT) angiography (CCTA)-derived machine learning fractional flow reserve CT (ML-FFRct) versus that of ischemia detected on single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) on incident cardiovascular outcomes.BackgroundSPECT MPI and ML-FFRct are noninvasive tools that can assess the hemodynamic significance of coronary atherosclerotic disease.MethodsWe studied a retrospective cohort of consecutive patients who underwent clinically indicated CCTA and SPECT MPI. ML-FFRct was computed using a ML prototype. The primary outcome was all-cause mortality and nonfatal myocardial infarction (D/MI), and the secondary outcome was D/MI and unplanned revascularization, percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) occurring more than 90 days postimaging. Multiple nested multivariate cox regression was used to model a scenario wherein an initial anatomical assessment was followed by a functional assessment.ResultsA total of 471 patients (mean age: 64 ± 13 year; 53% males) were included. Comorbidities were prevalent (78% hypertension, 66% diabetes, 81% dyslipidemia). ML-FFRct was <0.8 in at least 1 proximal/midsegment was present in 41.6% of patients, and ischemia on MPI was present in 13.8%. After a median follow-up of 18 months, 7% of patients (n = 33) experienced D/MI. On multivariate Cox proportional analysis, the presence of ischemia on MPI but not ML-FFRct significantly predicted D/MI (HR: 2.3; 95% CI: 1.0-5.0; P = 0.047; or HR: 0.7; 95% CI: 0.3-1.4; P = 0.306 respectively) when added to CCTA obstructive stenosis. Furthermore, the model with SPECT ischemia had higher global chi-square result and significantly improved reclassification. Results were similar using the secondary outcome and on several sensitivity analyses.ConclusionsIn a high-risk patient cohort, SPECT MPI but not ML-FFRct adds independent and incremental prognostic information to CCTA-based anatomical assessment and clinical risk factors in predicting incident outcomes.