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。     

Rationale and design of advantage (additional diagnostic value of CT perfusion over coronary CT angiography in stented patients with suspected in-stent restenosis or coronary artery disease progression) prospective study

BackgroundRecent studies demonstrated a significant improvement in the diagnostic performance of coronary CT angiography (CCTA) for the evaluation of in-stent restenosis (ISR). However, coronary stent assessment is still challenging, especially because of beam-hardening artifacts due to metallic stent struts and high atherosclerotic burden of non-stented segments. Adenosine-stress myocardial perfusion assessed by CT (CTP) recently demonstrated to be a feasible and accurate tool for evaluating the functional significance of coronary stenoses in patients with suspected coronary artery disease (CAD). Yet, scarce data are available on the performance of CTP in patients with previous stent implantation.Aim of the studyWe aim to assess the diagnostic performance of CCTA alone, CTP alone and CCTA plus CTP performed with a new scanner generation using quantitative invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR) as standard of reference.MethodsWe will enroll 300 consecutive patients with previous stent implantation, referred for non-emergent and clinically indicated invasive coronary angiography (ICA) due to suspected ISR or progression of CAD in native coronary segments. All patients will be subjected to stress myocardial CTP and a rest CCTA. The first 150 subjects will undergo static CTP scan, while the following 150 patients will undergo dynamic CTP scan. Measurement of invasive FFR will be performed during ICA when clinically indicated.ResultsThe primary study end points will be: 1) assessment of the diagnostic performance (diagnostic rate, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy) of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. ICA as standard of reference in a territory-based and patient-based analysis; 2) assessment of sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CCTA, CTP, combined CCTA-CTP and concordant CCTA-CTP vs. invasive FFR as standard of reference in a territory-based analysis.ConclusionsThe ADVANTAGE study aims to provide an answer to the intriguing question whether the combined anatomical and functional assessment with CCTA plus CTP may have higher diagnostic performance as compared to CCTA alone in identifying stented patients with significant ISR or CAD progression.     

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.     

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。     

Right ventricular dysfunction by computed tomography associates with outcomes in severe aortic stenosis patients undergoing transcatheter aortic valve replacement

BackgroundAlthough cardiac computed tomography angiography (CCTA) assessment of right ventricular dysfunction (RVD) is feasible, the incremental prognostic value remains uncertain in patients undergoing transcatheter aortic valve replacement (TAVR) evaluation. This study sought to determine the incremental clinical utility of RVD identification by CCTA while accounting for clinical and echocardiographic parameters.MethodsPatients who underwent multiphasic ECG-gated functional CCTA using dual-source system for routine TAVR planning were evaluated. Biphasic contrast protocol injection allowed for biventricular contrast enhancement. CCTA-based RVD was defined as right ventricular ejection fraction (RVEF) ?< ?50%. The association of CCTA-RVD with all-cause mortality and the composite outcome of death or heart failure hospitalization after TAVR was evaluated and examined for its incremental utility beyond clinical risk assessment and echocardiographic parameters.ResultsA total of 502 patients were included (median [IQR] age, 82 [77 to 87] years; 56% men) with a median follow-up of 22 [16 to 32] months. Importantly, 126 (25%) patients were identified as having RVD by CCTA that was not identified by echocardiography. CCTA-defined RVD predicted death and the composite outcome in both univariate analyses (HR for mortality, 2.15; 95% CI, 1.44–3.22; p ?< ?0.001; HR for composite outcome, 2.11; 95% CI, 1.48–3.01; p ?< ?0.001) and in multivariate models that included clinical risk factors and echocardiographic findings (HR for mortality, 1.74; 95% CI, 1.11–2.74; p ?= ?0.02; HR for composite outcome, 1.63; 95% CI, 1.09–2.44; p ?= ?0.02).ConclusionsFunctional CCTA assessment pre-TAVR correctly identified 25% of patients with RVD that was not evident on 2D echocardiography. The presence of RVD on CCTA independently associates with clinical outcomes post-TAVR.     

Comparative effectiveness of coronary screening in heart valve surgery: Computed tomography versus conventional coronary angiography

Background

Although conventional coronary angiography (CAG) is considered the gold standard for coronary artery disease (CAD) screening in the setting of heart valve surgery, coronary artery computed tomography angiography (CCTA) has emerged as an alternative modality. This study was conducted to evaluate the clinical outcomes of CCTA compared with conventional CAG for CAD screening in patients undergoing heart valve surgery.

D-dimer is associated with arterial and venous coronary artery bypass graft occlusion

Objective

In this observational prospective study, we assessed the role of clinical variables and circulating biomarkers in graft occlusion at 18 months to identify a signature for graft occlusion.