Assessing the value of coronary artery computed tomography as the first-line anatomical test for stable patients with indications for invasive angiography due to suspected coronary artery disease. Initial cost analysis in the CAT-CAD randomized trial

BackgroundClinical and safety outcomes of the strategy employing coronary computed tomography angiography (CCTA) as the first-choice imaging test have recently been demonstrated in the recently published CAT-CAD randomized, prospective, single-center study. Based on prospectively collected data in this patient population, we aimed to perform an initial cost analysis of this approach.Methods120 participants of the CAT-CAD trial (age:60.6 ± 7.9 years, 35% female) were included in the analysis. We analyzed medical resource use during the diagnostic and therapeutic episode of care. We prospectively estimated the cumulative cost for each strategy by multiplying the number of resources by standardized costs in accordance to medical databases and the 2015 Procedural Reimbursement Payment Guide.ResultsThe total cost of coronary artery disease (CAD) diagnosis was significantly lower in the CCTA group as compared to the direct invasive coronary angiography (ICA) group ($50,176 vs $137,032) with corresponding per-patient cost of $836 vs $2,284, respectively. Similarly, the entire diagnostic and therapeutic episode of care was significantly less expensive in the CCTA group ($227,622 vs $502,827) with corresponding per-patient cost of $4630 vs $8,380, respectively. Overall, the application of CCTA as a first-line diagnostic test in stable patients with indications to ICA resulted in a 63% reduction of CAD diagnosis costs and a 55% reduction composite of diagnosis and treatment costs during 90-days follow-up.ConclusionsApplication of CCTA as the first-line anatomic test in patients with suspected significant CAD decreased the total costs of diagnosis. This is likely attributable to reduced numbers of invasive tests and hospitalisations. Initial cost analysis of the CAT-CAD randomized trial suggests that this approach may provide significant cost savings for the entire health system.     

Determination of optimal fluoroscopic angulations for aorto-coronary ostial interventions from coronary computed tomography angiography

BackgroundAn optimal aorto-coronary angiographic projection, characterized by an orthogonal visualization of the proximal coronary artery, is crucial for interventional success. We determined the distribution of optimal C-arm positions and assessed their feasibility by invasive coronary angiography.MethodsOrthogonal aorto-coronary ostial angulations were determined in 310 CT data sets. In 100 patients undergoing subsequent invasive angiography, we assessed if the CT-predicted angulations were achievable by the C-arm system. If the predicted projection was not achievable due to mechanical constraints of the C-arm system, the most close, achievable angulation was determined. Patient characteristics were analyzed regarding the distribution of optimal angulations and its feasibility by the C-arm system.ResultsFor the left ostium, CT revealed a mean angulation of LAO 23 ?± ?21°/cranial 25 ?± ?23° (90% of patients with a LAO/cranial angulation, 3% LAO/caudal, 4% RAO/cranial, 3% RAO/caudal) and were achievable by the C-arm system in 87% of patients. For the right ostium, the mean CT-predicted orthogonal angulation was LAO 36 ?± ?37°/cranial 36 ?± ?51° (84% LAO/cranial, 2% LAO/caudal, 14% RAO/caudal) and achievable by the C-arm system in 45% of patients. For the left ostium, a higher body weight was associated with a steeper LAO/cranial angulation being less feasible by the C-arm system due to mechanical constraints.ConclusionsOrthogonal aorto-left coronary angulations show a relative narrow distribution predominately in LAO/cranial position whereas a wider range of angulations was found for the right coronary ostium. The feasibility of CT-predicted angulations by the C-arm system is more restricted for the right than the left coronary ostium.     

Bilateral coronary ostial stenosis secondary to syphilitic aortitis

Cardiovascular syphilis is associated with the tertiary stage of syphilis infection; it involves the ascending aorta and can cause aortic aneurysm, aortic regurgitation, and coronary ostial stenosis. We report here a case in which bilateral coronary ostial stenosis and aortic regurgitation due to syphilitic aortitis was diagnosed; coronary artery bypass graft was then performed.     

Evaluation of computed tomography coronary angiography in patients with a high heart rate using 16-slice spiral computed tomography with 0.37-s gantry rotation time

The aim of our study is to evaluate computed tomography (CT) coronary angiography in patients with a high heart rate using 16-slice spiral CT with 0.37-s gantry rotation time. We compare the image quality of patients whose heart rates were over 70 beats per minute (bpm) with that of patients whose heart rates were 70 bpm or less. Sixty patients with various heart rates underwent retrospectively ECG-gated multislice spiral CT (MSCT) coronary angiography. Two experienced observers who were blind to the heart rates of the patients evaluated all the MSCT coronary angiographic images and calculated the assessable segments. A total of 620 out of 891 (69.6%) segments were satisfactorily visualized. On average, 10.3 coronary artery segments per patient could be evaluated. In 36 patients whose heart rates were below 70 bpm [mean 62.2 bpm±5.32 (standard deviation, SD)], the number of assessable segments was 10.72±2.02 (SD). In the other 24 patients whose heart rates were above 70 bpm [mean 78.6 bpm±8.24 (SD)], the corresponding number was 9.75±1.74 (SD). No statistically significant difference was found in these two subgroups t test, P>0.05. The new generation of 16-slice spiral CT with 0.37-s rotation time can satisfactorily evaluate the coronary arteries of patients with high heart rates (above 70 bpm, up to 102 bpm).     

Associations between coronary artery stenosis detected by coronary computed tomography angiography and the characteristics of health checkup examinees in the Republic of Korea

IntroductionThis study was conducted on healthy adults without a diagnosis related to cardiovascular disease to investigate the associations between asymptomatic coronary artery stenosis and the characteristics of health checkup examinees.MethodsThis study was performed on 601 people (320 males and 281 females), who underwent coronary computed tomography angiography (CCTA), among health checkup examinees from January 2, 2015 to December 31, 2016. Those with any prior history of cardiovascular diseases, underwent coronary artery bypass grafting or coronary artery stenting in the past, those with atrial fibrillation, those suspected of contrast agent side effects, and those whose creatinine levels deviated from the normal range were excluded.ResultsThe mean age was 58.7 ± 8.0 years. Coronary artery stenosis was detected in 173 people (28.8%), and the mean coronary artery stenosis rate was 25.8 ± 12.8%. Regression analysis showed that coronary artery stenosis was influenced significantly by age, gender, glycated hemoglobin (HbA1c), past smoking duration, current smoking duration, and number of glasses of alcohol consumed (p < 0.05). In terms of the relationship between the presence of coronary artery stenosis and lifestyle habits, amount of alcohol consumed per day (p = 0.03), and patients with a longer period of past (p < 0.001) and current smoking duration (p = 0.01) had a significant effect on coronary artery stenosis.ConclusionThese results suggest that men aged 60 years or older, who have consumed large amounts of alcohol and cigarettes for a long time, require continuous management through tests such as a health checkup, because of the high probability of coronary artery stenosis, even in those without specific symptoms.     

Radiation dose estimates in dual-source computed tomography coronary angiography

The purpose of this study was to quantify radiation dose parameters of dual-source CT coronary angiography. Eighty patients underwent contrast-enhanced, retrospectively ECG-gated dual-source CT coronary angiography with heart rate-adapted ECG pulsing using two algorithms: In 40 patients, the tube current was reduced to 20% (A_min1) of the normal tube current (A_max) outside the pulsing window; in 40 patients tube current was reduced to 4% (A_min2) of A_max. Mean CTDI_vol in the A_min1 group was 45.1 ± 3.6 mGy; the mean CTDI_vol in the A_min2 group was 39.1 ± 3.2 mGy, with CTDI_vol in the A_min2 group being significantly reduced when compared to the A_min1 group (P < 0.001). A significant negative correlation was found between CTDI_vol and heart rate in group A_min1 (r = −0.82, P < 0.001), whereas no correlation was found between CTDI_vol and heart rate in group A_min2 (r = −0.066). Using the conversion coefficient for the chest, dual-source CT coronary angiography resulted in an estimated mean effective dose of 8.8 mSv in the A_min1 group and 7.8 mSv in the A_min2. Radiation exposure of dual-source CT coronary angiography using an ECG-pulsing protocol reducing the tube current to 20% significantly decreases with increasing heart rates, despite using wider pulsing windows at higher heart rates. When using a protocol with reduced tube current of 4%, the radiation dose is significantly lower, irrespective of the heart rate.     

Coronary plaque imaging by coronary computed tomography angiography

Coronary computed tomography angiography (CTA) has become the useful noninvasive imaging modality alternative to the invasive coronary angiography for detecting coronary artery stenoses in patients with suspected coronary artery disease (CAD). With the development of technical aspects of coronary CTA, clinical practice and research are increasingly shifting toward defining the clinical implication of plaque morphology and patients outcomes by coronary CTA. In this review we discuss the coronary plaque morphology estimated by CTA beyond coronary angiography including the comparison to the currently available other imaging modalities used to examine morphological characteristics of the atherosclerotic plaque. Furthermore, this review underlies the value of a combined assessment of coronary anatomy and myocardial perfusion in patients with CAD, and adds to an increasing body of evidence suggesting an added diagnostic value when combining both modalities. We hope that an integrated, multi-modality imaging approach will become the gold standard for noninvasive evaluation of coronary plaque morphology and outcome data in clinical practice.     

The value of Coronary Artery computed Tomography as the first-line anatomical test for stable patients with indications for invasive angiography due to suspected Coronary Artery Disease: CAT-CAD randomized trial

BackgroundThe aim of this prospective, randomized trial was to evaluate whether the use of coronary computed tomography angiography (CCTA) as the first-line anatomical test in patients with suspected significant coronary artery disease (CAD) may reduce the number of coronary invasive angiographies (ICA), and expand the use of CCTA in patients currently diagnosed invasively.Methods120 patients (age:60.6 ± 7.9 years, 35% female) with indications to ICA were randomized 1:1 to undergo CCTA versus direct ICA. Outcomes were evaluated during the diagnostic and therapeutic periods.ResultsThe number of invasively examined patients was reduced by 64.4% in the CCTA group as compared to the direct ICA group (21vs59,p < 0.0001). The number of patients with ICAs not followed by coronary intervention was reduced by 88.1% with the CCTA strategy (5vs42,p < 0.0001). Over the diagnostic and therapeutic course there were no significant differences regarding the median volume of contrast (CCTA 80.3 ml[65.0–165.0] vs ICA 90.0 ml[55.0–100.0], p = 0.099), while a non-significant trend towards higher radiation dose in the CCTA group was observed (9.9 mSv[7.0–22.1] vs 9.4 mSv[5.2–14.0], p = 0.05). There were no acute cardiovascular events.ConclusionsCCTA may hypothetically act as an effective ‘gatekeeper’ to the catheterization laboratory in the diagnosis of stable patients with current indications for ICA. This strategy may result in non-invasive, outpatient-based triage of two thirds of individuals without actionable CAD, obviating unnecessary invasive examinations. However, the longer follow-up is indispensable.ClinicalTrials.gov numberNCT02591992     

Quantification of coronary stenosis by dual source computed tomography in patients: a comparative study with intravascular ultrasound and invasive angiography

Objective

To determine the accuracy of dual-source CT (DSCT) to quantify coronary stenosis compared to intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA).

Methods

21 patients (23 vessels) were examined with DSCT, IVUS and invasive coronary angiography. Coronary minimal luminal diameter (MLD) and area (MLA) were measured in cross-sectional multi-planar reformatted images perpendicular to the vessel long-axis. The vessel cross-sectional area stenosis (MLA/CSA ratio) was calculated. DSCT results were compared with IVUS and QCA.

Results

A good correlation between DSCT and IVUS was noted for diameter and area stenosis (r = 0.69 and r = 0.73), with an overestimation of MLD stenosis by DSCT (+9.1%) and an underestimation of MLA stenosis (−5.8%). For MLD and MLA, high correlation coefficients (r = 0.78 and r = 0.90, respectively) were found between DSCT and IVUS; and the bias was almost zero (−0.41 mm and +0.1 mm², respectively).The correlation between DSCT and QCA was moderate (r = 0.60) for MLD stenosis with minor overestimation by DSCT (+4.0%) and moderate (r = 0.59) for MLD (bias, +0.01 mm).The cross-sectional area stenosis showed a moderate correlation (r = 0.59) between DSCT and IVUS (+0.00).

Conclusions

DSCT allows accurate quantification of coronary stenosis as compared to IVUS. An excellent correlation was found for the MLA between DSCT and IVUS.     

Coronary manifestations of Kawasaki Disease in computed tomography coronary angiography

Coronary arteritis in Kawasaki disease can lead to serious complications such myocardial infarction and sudden death. The identification of coronary manifestations with a method that is minimally invasive and of low radiation exposure is therefore important in paediatric patients with Kawasaki disease. Coronary CT angiography can be an attractive alternative to invasive coronary angiography. This paper describes imaging techniques for coronary CT angiography in pediatric patients and demonstrates the spectrum of cardiovascular manifestations in patients with Kawasaki disease.     

Noninvasive gadolinium-enhanced three dimensional computed tomography coronary angiography

RATIONALE AND OBJECTIVES: Although the use of gadolinium (Gd)-based contrast agents for angiographic studies of abdominal aorta, renal vasculature, and digital subtraction angiography has been reported, no studies have shown their diagnostic efficacy and image quality in coronary computed tomography angiography (CTA). The aim of this study is to evaluate the image quality of Gd-based contrast agents during coronary CTA. MATERIALS AND METHODS: A phantom study was done to evaluate the attenuation of serial dilutions of Gd and iodinated agents. This study was done on a 64-slice multirow detector CT (MDCT) scanner and e-speed scanner and CT attenuation Hounsfield units (CTHU) were compared. We evaluated 35 consecutive patients who underwent Gd-enhanced CTA. CTHU of aorta was measured at first, mid, and lowest slice levels with and without contrast administration. The image quality was graded on the basis of visualization of the coronary arteries (scale I-III; III demonstrating diagnostic image quality of the distal-most vessels). In a substudy, four patients with borderline renal insufficiency underwent CTA using Gd and iodinated contrast agents admixed in a 50:50 ratio. RESULTS: The phantom study showed that enhancement of various dilutions of Gd and iodine resulted in near identical CTHU with both e-speed and 64-slice scanners (r(2) > or = 0.997). Mean CTHU with contrast at the top slice was 116 HU, at middle slice was 125 HU, and at the lower slice was 93 (111.14 +/- 22). Quality evaluation showed 2 grade III, 9 grade II, and 24 grade I images (average quality of images 1.35). Mean CTHU was 222. CONCLUSION: Gd-enhanced contrast medium provides adequate enhancement of coronary vasculature, allowing for diagnostic evaluation of coronary arteries with new CT systems. Use of newer generations of multirow detector CT scanners should further enhance the quality of images.     

冠状动脉狭窄的电子束CT诊断

目的：评价电子束CT(EBCT)及其三维血管成像对冠状动脉狭窄诊断的准确性及局限性。方法：37例经EBCT冠状动脉增强扫描和三维重建的患者，均又经常规心血管造影检查(CAG)。由两名不知其它检查结果的放射科医师将冠状动脉左主干(LM)和左前降支(LAD)、左回旋支(LCX)、右冠状动脉(RCA)的近、中段评价后与造影结果逐段对照．并作统计学分析。结果：在CAG结果≥2mm的219个冠状动脉节段中，EBCT可评价的有228(91.6％)个，无法评价的21(8．1％)个，影响因素最主要为广泛钙化遮蔽管腔。EBCT诊断冠状动脉各主干近、中段≥50％狭窄总的敏感性、特异性和阳性预测值、阴性预测值分别为80．1％、91．3％、72．4％、92．5％。其中左主干均为100％．前降支分别为90．4％、94．2％、84．5％和96．1％。结论：EBCT是较好的无创性冠状动脉成像技术，对冠状动脉左主干和前降支近、中段狭窄的评价具有极高的准确性．虽然无法替代CAG，但极具临床应用潜力。局限性是空间分辨率低，价格昂贵。     

Individually adapted, interactive multiplanar reformations vs. semi-automated coronary segmentation and curved planar reformations for stenosis detection in coronary computed tomography angiography

Objective

To evaluate, whether semi-automated vessel extraction and curved planar reformations (“automated vessel extraction”) increases diagnostic accuracy in the detection of relevant coronary artery lesions compared to manual, interactive multiplanar interpretation (“manual approach”).

Materials and methods

50 coronary CT angiography datasets were evaluated by four independent readers (two experienced, two novice) for the presence of stenoses exceeding 50% diameter reduction. One experienced and one novice reader each used the “manual approach” for cases 1–25 and “automated vessel extraction” for cases 26–50, while the other two readers used the complementary method. Results were compared to those of invasive coronary angiography.

Results

Using the “manual approach”, 37 of 42 stenoses were correctly detected by experienced as well as novice readers. 14 vs. 17 lesions were false positive (sensitivity 88%, specificity 91% vs. 89%, PPV 73% vs. 69%, NPV 97%, n.s.). Using “automated vessel extraction”, experienced readers detected 35/42 stenoses compared to 31/42 for novice readers. 7 vs. 11 lesions were missed and 17 vs. 15 false-positive lesions reported (sensitivity 83% vs. 74%, specificity 89% vs. 90%, PPV 67%, NPV 95% vs. 93%, n.s.).In patient-based analysis, for novice readers sensitivity was higher using the “manual approach” (97%, 29/30 pts. vs. 80%, 24/30 pts., p = 0.069).

Conclusions

Semi-automated vessel extraction and curved multiplanar reconstructions do not improve the diagnostic accuracy of coronary CT angiography compared to the use of interactive multiplanar reformations. Especially for less experienced readers, the use of automatically rendered curved multiplanar reconstructions alone cannot be recommended.     

Use of postmortem computed tomography angiography to detect vascular injuries accompanying skull base fracture

A 58-year-old woman who had presented for upper gastrointestinal barium examination accidently slipped from the movable bed, and her head became compressed between the end of the bed and the side wall. She suffered massive bleeding from her nose and ear followed by cardiac arrest, and subsequent attempts at cardiopulmonary resuscitation failed. A medicolegal autopsy was performed to reveal the cause of death, as part of the investigation of the accident. During the autopsy, postmortem cerebral CT angiography was carried out by injection of 5% gelatin-barium emulsion as a radiopaque contrast medium into the bilateral common carotid arteries, demonstrating transudation of the contrast medium into the right acoustic meatus and the sphenoidal sinus cavity. Considering that the body appeared anemic and that PMCTA suggested vascular injuries, the cause of death was definitively determined to be hemorrhagic shock due to injuries to the right internal carotid artery, accompanied by skull base fracture. Postmortem CT angiography played an important role in confirming that the vascular injuries had been responsible for the bleeding, as the lesions could not be fully confirmed by native CT or macroscopic examination.     

Usefulness of coronary postmortem computed tomography angiography to detect lesions in the coronary artery and myocardium in cases of sudden death

Coronary postmortem computed tomography angiography (coronary PMCTA) has been introduced as a routine examination procedure for autopsy at our department. Here, we reviewed eight autopsy cases in which apparent histopathological changes including acute myocardial infarction (AMI), anomalous aortic origin of a coronary artery (AAOCA), hypertrophic obstructive cardiomyopathy (HOCM) and acute myocarditis were involved in the cause of death. For investigation of the coronary artery and shape of the heart, coronary PMCTA was valuable in detecting narrowing or obstruction of coronary artery in AMI, indicating an anomalous aortic origin of the left coronary artery in AAOCA, and demonstrating septal hypertrophy and intracavitary obstruction in HOCM. However, it was debatable whether the hypervascularity demonstrated by coronary PMCTA in the case of acute myocarditis was more prominent than the vascular images obtained in other cases without inflammation. Thus, coronary PMCTA appeared to be useful not only for detection of coronary artery stenosis, but also for indicating other distinctive changes involved in AAOCA and HOCM.     

Dual source computed tomography coronary angiography in new onset cardiomyopathy

AIM:To evaluate safety and utility of coronary computed tomography angiography(CCTA) compared to invasive coronary angiography(ICA) in new cardiomyopathy.METHODS:Eighteen patients(mean age 56.5 years,10 males) who presented for evaluation of new onset heart failure with evidence of systolic dysfunction(ejection fraction < 40%) on echocardiography and recent ICA were prospectively enrolled.Patients with known coronary artery disease,atrial fibrillation,creatinine > 1.5 g/dL,and contraindication to intravenous contrast administration were excluded.CCTA was performed using a dual source 64-slice scanner.Mean heart rate was 75 beats per minute.Stenosis was graded for each coronary segment as:none,mild(< 50%),moderate(50%-70%),severe(> 70%),or non-evaluable.Ischemic cardiomyopathy(ICM) was diagnosed if severe stenosis was present in the left main,proximal left anterior descending artery,or two or more major arteries.RESULTS:Two patients were diagnosed with ICM by ICA.CCTA correctly identified 2 patients with ICM and 16 patients as non-ICM.CCTA successfully evaluated 240/246 coronary segments with an accuracy of 97.5%,sensitivity 70%,specificity 98.7%,positive predictive value of 70%,and negative predictive value of 98.7% for identifying severe stenosis on a per-segment level.CONCLUSION:Dual source 64-slice multi-detector CCTA is a safe,accurate,and non-invasive technique for diagnosing ICM in patients presenting during the acute phase of newly diagnosed cardiomyopathy.     

冠状动脉CT血管成像和运动平板试验对冠心病患者的诊断比较

目的:评价冠状动脉CT血管成像(CCTA)和运动平板试验(TET)对冠心病的诊断价值。方法:以常规冠状动脉造影(CAG)为诊断冠心病(冠脉狭窄≥50%)的"金标准",对同期先后行TET、CCTA和CAG 3种检查的75例疑似冠心病患者进行回顾性分析,将其TET和CCTA的结果与CAG进行比较。结果:TET和CCTA诊断冠心病的敏感度分别为45.2%和90.5%,特异度为69.7%和93.9%,阳性预测值为65.5%和95.0%,阴性预测值为50.0%和88.6%,准确率为56.0%和92.0%,P<0.01。在冠状动脉血管水平CCTA对右冠状动脉、左主干、前降支、回旋支狭窄诊断的准确率分别为86.7%、100.0%、88.0%和76.0%。冠心病患者中TET诊断阳性率与病变血管支数呈正相关(r=0.440,P=0.004);冠心病患者TET诊断结果阳性与阴性仅与血管狭窄程度≥75%狭窄的节段数目有统计学差异(P=0.016)。结论:CCTA诊断冠心病较TET有更高的诊断准确性和较低的诊断假阳性和假阴性,对有症状的疑诊冠心病患者CCTA的诊断具有更重要作用。