Use Of Coronary Computed Tomography Angiography Research Articles

Coronary CTA assessment of coronary anomalies

Coronary anomalies occur in <1% of the general population and can range from a benign incidental finding to the cause of sudden cardiac death. The coronary anomalies are classified here according to the traditional grouping into those of origin and course, intrinsic arterial anatomy, and termination. Classic coronary anomalies of origin and course include those in which a coronary artery originates from the contralateral aortic sinus or the pulmonary artery with anomalous course. Single coronary artery anomalies, in which single coronary artery branches to supply the entire coronary tree, are also included in this category. Anomalies of intrinsic arterial anatomy are a broad class that includes myocardial bridges, coronary ectasia and aneurysms, subendocardial coursing arteries, and coronary artery duplication. Coronary anomalies of termination are those in which a coronary artery terminates in a fistulous connection to a great vessel or cardiac chamber. In the case of those anomalies associated with a risk of sudden cardiac death, the relevant imaging features on CT angiography (CTA) associated with poorer prognosis are reviewed. Recent guidelines and appropriateness criteria favor the use of coronary CTA for the evaluation of coronary anomalies. Although invasive angiography has historically been used to diagnose coronary anomalies, multidetector CT imaging techniques have now become an accurate noninvasive alternative. Cardiac CTA provides excellent spatial and temporal resolution, allowing accurate anatomical assessment of these anomalies.

Anomalous origination of a coronary artery from the opposite sinus

Anomalous origination of a coronary artery from the opposite sinus (ACAOS) is estimated to be present in 0.2-2.0% of the population. In the majority of individuals, ACAOS has no hemodynamic or prognostic implications, but in a minority of cases, typically where the anomalous coronary artery takes an interarterial course to reach its correct myocardial territory, it can precipitate ischemia and sudden cardiac death (SCD). With the growing use of CT coronary angiography (CTCA) in the investigation of ischemic heart disease, we can expect increasing rates of incidental detection of this anomaly. Although CTCA and magnetic resonance coronary angiography can effectively characterize these lesions anatomically, they fail to describe and quantitatively assess the basic defect that leads to coronary insufficiency, such as mural intussusception. The key challenge lies in the identification of which patients are at risk of SCD and, therefore, who should be offered corrective surgical or (potentially) percutaneous intervention. Conventional, noninvasive stress testing has limited sensitivity, but emerging, invasive stress tests, which utilize intravascular ultrasonography and measurements of fractional flow reserve, show the potential to provide more-accurate hemodynamic and prognostic assessment.

The Lack of Growth in Use of Coronary CT Angiography: Is It Being Appropriately Used?

The purpose of this article is to study recent utilization trends in coronary CT angiography (CTA) and compare them with radionuclide myocardial perfusion imaging (MPI), a competing procedure. The nationwide Medicare Part B databases were used to determine utilization rates per 100,000 beneficiaries. Rates for coronary CTA were studied from 2006 (the first year Current Procedural Terminology codes were available for this procedure) through 2008. Rates for MPI were studied from 1998 through 2008. Medicare specialty codes were used to identify examinations done by radiologists and cardiologists. The coronary CTA total utilization rate per 100,000 rose from 99 in 2006 to 210 in 2007 (112%) but then decreased to 193 in 2008 (-8%). The rate for MPI increased from 4748 in 1998 to a peak of 8753 in 2006 (84%), then declined to 8467 in 2008. Cardiologists performed the majority of both coronary CTA and MPI. In 2008, MPI was performed 44 times as often as coronary CTA. Given that coronary CTA is a new procedure that has aroused much interest and has been shown to have very favorable results, the drop in its utilization rate in 2008 was surprising. A review of the literature indicates that there are shortcomings to the clinical diagnosis of coronary artery disease (which often includes the use of MPI), that coronary CTA can be used to stratify risk, and that it can expedite the workup of patients with acute chest pain in emergency departments. The evidence from the literature review suggests that both invasive coronary angiography and MPI may be overutilized, whereas coronary CTA is probably underutilized.

Coronary anomaly diagnosed by computed tomography coronary angiography in a patient with atypical chest pain

A 64-year-old man was evaluated for atypical chest pain that was present during transurethral prostatectomy. He had no risk factors for coronary artery disease (CAD), no prior history of ischaemic heart disease and had not experienced any symptoms of chest pain during exercise before. Computed tomography coronary angiography (CTCA) was performed to exclude CAD. CTCA (Fig. 1) showed a normal right coronary artery (RCA). An aberrant circumflex coronary artery (CX) originated from the right coronary sinus and followed a benign retro-aortic course. A small coronary artery originated from the left coronary sinus and followed an anterolateral course. An anomalous left coronary artery originated from the right coronary sinus and followed an interarterial course between the aortic root and pulmonary trunk to the left ventricular anterior myocardial wall. Nonobstructive calcified atherosclerotic plaque was observed in the proximal RCA and mid CX. These findings were confirmed by invasive coronary angiography. Fig. 1 Computed tomography coronary angiography images (Siemens Sensation 64, collimation 64 × 0.6 at 900 mAs and 120 kV). Three-dimensional reconstruction (a) and transverse images (b, c, d) showing a normal right coronary ... Exercise and rest single-photon emission computed tomography (SPECT) imaging showed normal myocardial perfusion and no significant electrocardiographic changes were observed (Fig. 2). As the patient had never experienced any chest pain before and exercise-induced ischaemia was absent, he was treated conservatively with β-blockers. During a 6-month follow-up, he did not experience any chest pain. Fig. 2 Exercise stress (a) and rest (b) single-photon emission computed tomography images showing normal myocardial perfusion in all myocardial segments Coronary anomalies have a reported overall prevalence of 5.6%. Coronary anomalies originating from the opposite sinus have a reported prevalence of 1.0% [1]. They have a worse prognosis due to torsion or slit-like compression of the proximal parts, vasospasm, exercise-induced compression and ischaemic-induced ventricular arrhythmia. In contrast to more conventional noninvasive tests for the evaluation of patients with suspected CAD, such as exercise ECG and SPECT, CTCA visualises the coronary anatomy and atherosclerosis accurately [2]. With the increased use of CTCA in clinical practice, coronary anomalies may be detected more frequently. However, still little is known with respect to the appropriate treatment, and evidence is largely based on case reports. Recent expert opinions suggested stress nuclear testing as additional functional test to evaluate the presence of effort-induced ischaemia [1] and stated that older patients (>35 years) without inducible ischaemia may not need surgical therapy [3]. Recently, an ACC/AHA guideline [4] recommended surgical revascularisation of coronary anomalies with an interarterial course and documented ischaemia (class 1). In contrast, surgical revascularisation of the left anterior descending coronary artery with an interarterial course but without documented ischaemia was classified as a 2b indication and might be considered. Thus, CTCA can visualise coronary anomalies accurately; however, functional tests are still warranted to evaluate its haemodynamic relevance [5] and to direct further treatment.

An S-shaped sinoatrial nodal artery coronary artery fistula demonstrated by multidetector CT

The presented case and discussion illustrate the use of CT coronary angiography to depict coronary artery fistulae. A 41-year-old man presented with an acute myocardial infarction. Invasive angiography revealed an incidental coronary artery fistula but was unable to depict its course. CT coronary angiography was undertaken to define the course and termination of the fistula. This confirmed a fistulous connection between the left circumflex artery and the superior vena cava that followed the typical course of an S-shaped sinoatrial nodal artery. Even in such an unusual anomaly this case highlights the ability of CT coronary angiography to accurately depict the coronary artery anatomy.

190: Real World Use of 320 Detector Computed Tomography Coronary Angiography for Chest Pain Triage In the Emergency Department

Chest pain is a common presenting complaint in emergency department (ED) patients. While diagnosing acute coronary syndrome (ACS) is straightforward, evaluating the extent of coronary artery disease (CAD) is time and resource intensive. Routine use of outpatient stress testing does not guarantee follow-up for all patients. Computed tomography coronary angiography (CTCA) makes it possible to conduct CAD testing prior to ED discharge. The purpose of this study was to evaluate the real-world effectiveness of CTCA in ED patients with chest pain. We conducted a cohort study comparing outcomes in 100 ED patients with chest pain from a single academic center by an intention to treat analysis. One patient cohort (n=50) underwent CTCA during the index ED visit while the other cohort (n=50) was given a prescription for an outpatient stress test. Comparisons were made of the duration of ED visit, the completion of CAD testing, and 3-month adverse events (return ED visit for chest pain, myocardial infarction, or death). Standard statistical methods for comparing continuous and categorical variables were used. Differences in baseline characteristics were negligible. The CT cohort was older (mean age 47.0 years versus 41.3 in control, p = 0.009) and mean BMI in both cohorts was in the obese range (31.5 kg/m2 for the CT cohort, 31.6 kg/m2 for control, p = 0.94) CAD testing was completed in significantly more patients in the CT cohort (48 patients versus 18 patients in the control cohort, p < 0.0001). For 2 CT patients, scanner malfunction resulted in no scan being performed, while in control patients, 32 failed to complete follow-up testing. Three CTCA studies were nondiagnostic due to excessive artifacts. Median CAC was 0 Agatston units (interquartile range [IQR] 0 - 1.5) and 34 patients (71% of 48 with successful CTCA) had a CAC score of zero. Detection of CAD was significantly higher in the CT cohort (14 patients versus 1 patient in the control cohort, p = 0.0004). Obstructive CAD (> 50% stenosis of a coronary artery) was found in 6 CT patients and only 1 control patient (p = 0.11). Median duration of stay was 417.5 minutes (IQR 359 - 581) in the CT cohort and 400 minutes (IQR 338 - 471) in the control cohort (p = 0.53). Patient subgroups were evaluated based on their time of ED arrival, but no subgroup had significantly different duration of stay. During 3 months of follow-up, four patients in each cohort were reevaluated in the ED for chest pain, while no patients suffered MI or death. The routine use of CTCA for evaluating ED patients with chest pain dramatically improves completion of CAD testing without any significant effect on the duration of stay. The prevalence of CAD in the tested population is notable and the majority of patients with CAD will go undetected using a strategy of routine outpatient follow-up stress testing. After ruling out ACS, patients can likely be discharged safely with expected 3-month event rates to be low. Further study is necessary to determine if greater accuracy in CTCA detecting CAD could reduce adverse outcomes, return ED visits, and redundant workups for chest pain.

Stress echocardiography in the age of multi-detector computed tomography

The introduction of 64-slice multi-detector computed tomography (CT) in 2005 made the non-invasive imaging of coronary arteries relatively easy to perform. Computed tomography coronary angiography (CTCA) has been shown to be highly accurate at detecting coronary artery disease (CAD), when compared with invasive X-ray coronary angiography and, in particular, has an excellent negative predictive value (NPV).1,2 There are also prognostic data confirming very low risk for patients with normal CTCA.3 One of the limitations of multidetector CT and despite very good temporal resolution of 150 ms, with half scan reconstruction, is the need for beta-Blockers to slow the heart rate to 65 bpm, for retrospective, and 60 bpm, for the low radiation dose, prospective gated acquisitions. This is to minimize coronary motion particularly of the right coronary artery. Dual-source CT, with twice the temporal resolution, can cope with faster heart rates, whereas the 320-slice CT can image the heart in one heart beat. The UK national institute of clinical excellence (NICE) have recently produced guidelines on the management of patients with chest pain of recent onset, endorsing the use of CTCA in their investigational algorithm. We discuss the radiation dose associated with …

Use of CT Coronary Angiography for Intermediate Risk Chest Pain and Correlation with Catheter Angiography

Conclusion: In prospective triggered scanning, reducing the tube voltage (100 kV) resulted in approximately 50% reduction in radiation. The removal of padding saw a further 50% reduction, resulting in radiation just above 1mSv. doi:10.1016/j.hlc.2010.06.487

Diagnostic performance of CT coronary angiography for the detection of obstructive coronary artery disease

CT coronary angiography (CTCA) is emerging as the most promising imaging modality for noninvasive detection of atherosclerotic disease of the coronary arteries. The possibility to identify or rule out significant coronary stenosis, to measure atherosclerotic plaque burden, and to characterize plaque components makes this imaging modality very enticing. This review briefly summarizes CTCA’s technical aspects, limitations, and pitfalls, as well as different methods of analyses of diagnostic performance of CTCA. It also provides clinical indications for the use of CTCA and discusses its use in patients with prior coronary stent placement and coronary artery bypass grafting.

The impact of cardiac CT on the appropriate utilization of catheter coronary angiography

The purpose of this study was to evaluate the impact of computed tomography coronary angiography (CTCA) on the appropriate utilization of catheter angiography (CA). This observational trial analyzed all patients undergoing CA in 2006 and 2007 in one hospital. In 2007, patients having a low to intermediate cardiovascular risk and suspicion of coronary artery disease (CAD) and those with suspicion of progression of known organic heart disease (OHD) underwent CTCA either prior to CA or as the sole imaging modality. Appropriate utilization of CA was defined as: (1) percentage of patients showing normal or non-significant findings at CA, (2) percentage of self-referred patients to CA, and (3) percentage of patients with known OHD undergoing CA without immediate operative or interventional consequences. Use of CTCA resulted in a significant drop in the percentage of CA examinations in patients with suspected CAD showing normal or non-significant findings (19% in 2006, 10% in 2007, P < 0.001). The percentage of self-referred CA significantly dropped (29% in 2006, 10% in 2007, P < 0.001). CT ruled-out CAD in 74/151 (49%) patients, obviating subsequent CA. During a follow-up of 15 +/- 4 months, CA and percutaneous interventions was considered necessary in 2/74 patients. CT ruled-out progression of known OHD in 53/60 (90%) patients, while one patient underwent CA and percutaneous intervention during a follow-up period of 16 +/- 4 months. No reduction of CA examinations without immediate consequences was found in patients with known OHD (13% in 2006, 27% in 2007). In patients with suspicion of CAD, CTCA improved the appropriate utilization of CA without jeopardizing patient safety, along with a decrease of self-referred patients for CA. CTCA did not influence the appropriate utilization of CA in patients with known OHD.

CT angiography versus invasive angiography for the diagnosis of total occlusion

Computed tomography coronary angiography (CTCA) for the diagnosis and evaluation of coronary artery occlusive disease has rapidly gained acceptance among clinicians. Its growing use in selected populations has provided a wealth of data, leading to a recent flurry of articles describing both the benefits and limitations of this imaging modality. In this article, we describe the case of an 80 year old woman who presented with anginal symptoms, who first underwent CTCA which suggested severe right coronary artery stenosis. A subsequent invasive coronary angiogram was crucial in revealing a total occlusion and the presence of collateral vessels, findings that would ultimately guide therapy. This case demonstrates a significant limitation in the use of CTCA and the associated images are valuable in illustrating this point.

Is there a role for CT coronary angiography in patients with symptomatic angina? Effect of coronary calcium score on identification of stenosis

Present guidelines discourage the use of CT coronary angiography (CTCA) in symptomatic angina patients. We examined the relation between coronary calcium score (CS) and the performance of CTCA in patients with stable and unstable angina in order to understand under which conditions CTCA might be a gate-keeper to conventional coronary angiography (CCA) in such patients. We included 360 patients between 50 and 70 years old with stable and unstable angina who were clinically referred for CCA irrespective of CS. Patients received CS and CCTA on 64-slice scanners in a multicenter cross-sectional trial. The institutional review board approved the study. Diagnostic performance of CTCA to detect or rule out significant coronary artery disease was calculated on a per patient level in pre-defined CS categories. The prevalence of significant coronary artery disease strongly increased with CS. Negative CTCA were associated with a negative likelihood ratio of <0.1 independent of CS. Positive CTCA was associated with a high positive likelihood ratio of 9.4 if CS was <10. However, for higher CS the positive likelihood ratio never exceeded 3.0 and for CS >400 it decreased to 1.3. In the 62 (17%) patients with CS <10, CTCA reliably identified the 42 (68%) of these patients without significant CAD, at no false negative CTCA scans. In symptomatic angina patients, a negative CTCA reliably excludes significant CAD but the additional value of CTCA decreases sharply with CS >10 and especially with CS >400. In patients with CS <10, CTCA provides excellent diagnostic performance.

Non-invasive coronary angiography using multi-detector computed tomography – Update 2008

Non-invasive visualization of the coronary arteries and detection of significant coronary artery stenosis using conventional CT technology started in the year 1999 when 4-slice multi-detector CT (MDCT) systems were introduced. In the following years, spatial and technical resolution of MDCT coronary angiography rapidly evolved. State of the art 64-slice CT systems with a spatial resolution of up to 0.4 mm and rotation times below 300 ms provide a very reliable evaluation of the heart and the coronary arteries. Due to a consistently high negative predictive value, MDCT coronary angiography has demonstrated to be a useful imaging modality to exclude significant coronary artery stenosis especially in patients with a low to intermediate pretest likelihood. Prominent recent technical developments, e.g., dual-source CT technology or 320-slice MDCT, as well as the development of dose saving scan protocols will further improve the use of CT coronary angiography. This review summarizes the available literature concerning diagnostic accuracy, prognostic relevance and radiation exposure. Current scientific statements concerning possible clinical indications of CT coronary angiography are included.

The Pre-Test Risk Stratified Cost-Effectiveness of 64-Slice Computed Tomography Coronary Angiography in the Detection of Significant Obstructive Coronary Artery Disease in Patients Otherwise Referred to Invasive Coronary Angiography

This study evaluates the cost-effectiveness of 64-slice computed tomography coronary angiography (CTCA) as an alternative to invasive diagnostic coronary angiography (CA) in an elective outpatient setting for patients otherwise referred to invasive diagnostic coronary angiography. Taking the perspective of the Australian health system we used a decision analytic model to integrate data on test accuracy along with complication rates, health state preference weights and health care costs. The analysis is pre-test risk stratified based on Bayes' theorem of conditional probability. Incremental cost-effectiveness ratios (ICER) are the study endpoints expressed as incremental costs per quality adjusted life year (QALY) gained. The results indicate that CTCA is a cost-saving strategy offering a higher health related quality of life up to approximately 65% pre-test risk of coronary artery disease (CAD). Above that threshold the model predicts a cost-utility trade-off with every gain in health related quality of life through the use of CTCA as a rule-out test being associated with additional costs when compared to invasive diagnostic CA. This health economic analysis predicts computed tomography coronary angiography to be a cost-effective rule-out strategy in symptomatic patients at low to intermediate risk of significant obstructive coronary artery disease otherwise referred to invasive diagnostic CA.

Preoperative and Postoperative Evaluation of Multiple Giant Coronary Aneurysms by the Use of Coronary CT Angiography with 64-MDCT: A Case of Multiple Giant Coronary Aneurysms Treated with Aneurysmectomy and Coronary Artery Bypass Surgery

A coronary artery aneurysm is an uncommon disorder and is seen as a characteristic dilatation of a localized portion of the coronary artery. Clinical manifestation of a coronary artery aneurysm varies from an asymptomatic presentation to sudden death of a patient. Although coronary aneurysms are typically diagnosed by the use of coronary angiography, a new generation of coronary 64-slice multidetector computed tomography (64-MDCT) scanners have successfully been used for evaluating this abnormality in a noninvasive manner. In the present case, we performed coronary 64-MDCT scanning preoperatively and postoperatively on a patient with multiple giant coronary aneurysms. The use of coronary 64-MDCT may provide an evaluation technique not only for diagnosis but also for follow-up after surgery for this condition.

Diagnosis of Variants of Single Right Coronary Trunk Using 64 Multidetector Computed Tomography

Single coronary anomalies are one of the rarest variants of coronary anatomy. Widespread use of coronary CT angiography has made it possible to diagnose these variants with increasing incidence. We report two cases of single right coronary trunk with different anatomic course of the left coronary artery; one anterior to the main pulmonary artery and the second between the main pulmonary artery and ascending aorta and then coursing within the interventricular septum.

Abstract 2004: Usefulness of Coronary CT Angiography in the Early Triage of Patients with Acute Chest Pain

Background: Early triage of patients with acute chest pain in the emergency department (ED) may be improved by rapid noninvasive assessment of coronary artery disease (CAD) by coronary computed tomography angiography (CTA). We sought to determine the usefulness of coronary CTA for the early triage of patients with acute chest pain but an inconclusive initial ED evaluation. Methods: Single center, double-blinded observational cohort study in the ED of a large tertiary academic hospital enrolling 368 consecutive patients with acute chest pain and inconclusive initial ED evaluation (normal initial troponin and an initial ECG without evidence of myocardial ischemia) who were awaiting hospital admission between May 2005 and May 2007. All patients underwent 64-slice contrast-enhanced coronary CTA prior to hospital admission with caregivers and patients blinded to the results of the examination. Diagnostic accuracy and discriminatory power of coronary CTA findings (coronary plaque and stenosis [&gt;50% luminal narrowing]) for acute coronary syndrome (ACS) during index hospitalization and major adverse cardiac events (MACE) during 6- month follow-up. Results: Among 368 patients (mean age 53±12 years, 61% male) 31 (8%) developed ACS but no MACE occurred during follow-up. Fifty percent (n=183) of the study population had neither plaque nor stenosis, a finding which had 100% negative predictive value (95% confidence interval [CI]: 98 to 100%) for ACS. In adjusted analysis, the extent of coronary plaque and presence of stenosis were associated with an increased risk for ACS (OR: 1.28, 95% CI: 1.14 to 1.43 and OR: 11.69, 95% CI: 4.4 to 31.0; respectively). Coronary CT findings (no CAD, plaque but no stenosis, and stenosis) discriminated patients at low, intermediate, or high risk of ACS (OR: 8.65, 95% CI: 3.69 to 20.26; AUC: 0.91). Conclusion : Half of the patients with acute chest pain and low to intermediate likelihood of ACS have no CAD and may be safely discharged directly from the ED. Coronary CT has excellent discriminatory power in defining patient risk for ACS.

98: Diagnostic Usefulness of Coronary CT Angiography in Patients with Symptomatic, but Atypical Chest Pain: Anatomic versus Perfusion Imaging

98: Diagnostic Usefulness of Coronary CT Angiography in Patients with Symptomatic, but Atypical Chest Pain: Anatomic versus Perfusion Imaging