Usefulness of noninvasive MSCT coronary angiography as first-line imaging technique in patients with chest pain: initial clinical experience

Accuracy of multidetector computed tomography for detection of coronary artery stenosis in acute coronary syndrome compared with stable coronary disease: a CORE64 multicenter trial substudy

BACKGROUND

Multi-detector computed tomography angiography (MDCTA) is a promising method for risk assessment of patients with acute chest pain. However, its diagnostic performance in higher-risk patients has not been investigated in a large international multicenter trial. Therefore, in the present study we sought to estimate the diagnostic accuracy of MDCTA to detect significant coronary stenosis in patients with acute coronary syndrome (ACS).

METHODS

Patients included in the CORE64 study were categorized as suspected-ACS or non-ACS based on clinical data. A 64-row coronary MDCTA was performed before invasive coronary angiography (ICA) and both exams were evaluated by blinded, independent core laboratories.

RESULTS

From 371 patients included, 94 were categorized as suspected ACS and 277 as non-ACS. Patient-based analysis showed an area under the receiver-operating-characteristic curve (AUC) for detecting ≥ 50% coronary stenosis of 0.95 (95% CI: 0.88-0.98) in ACS and 0.92 (95% CI: 0.88-0.95) in non-ACS group (P=0.29). The sensitivity, specificity, positive and negative predictive values of MDCTA were 0.90(0.80-0.96), 0.88(0.70-0.98), 0.95(0.87-0.99) and 0.77(0.58-0.90) in suspected ACS patients and 0.87(0.81-0.92), 0.86(0.79-0.92), 0.91(0.85-0.95) and 0.82(0.74-0.89) in non-ACS patients (P NS for all comparisons). The mean calcium scores (CS) were 282 ± 449 in suspected ACS and 435 ± 668 in non-ACS group. The accuracy of CS to detect significant coronary stenosis was only moderate and the absence or minimal coronary artery calcification could not exclude the presence of significant coronary stenosis, particularly in ACS patients.

CONCLUSIONS

The diagnostic accuracy of MDCTA to detect significant coronary stenosis is high and comparable for both ACS and non-ACS patients.

ACR Appropriateness Criteria(®) acute nonspecific chest pain-low probability of coronary artery disease

This document outlines the usefulness of available diagnostic imaging for patients without known coronary artery disease and at low probability for having coronary artery disease who do not present with classic signs, symptoms, or electrocardiographic abnormalities indicating acute coronary syndrome but rather with nonspecific chest pain leading to a differential diagnosis, including pulmonary, gastrointestinal, or musculoskeletal pathologies. A number of imaging modalities are available to evaluate the broad spectrum of possible pathologies in these patients, such as chest radiography, multidetector CT, MRI, ventilation-perfusion scans, cardiac perfusion scintigraphy, transesophageal and transthoracic echocardiography, PET, spine and rib radiography, barium esophageal and upper gastrointestinal studies, and abdominal ultrasound. It is considered appropriate to start the assessment of these patients with a low-cost, low-risk diagnostic test such as a chest x-ray. Contrast-enhanced gated cardiac and ungated thoracic multidetector CT as well as transthoracic echocardiography are also usually considered as appropriate in the evaluation of these patients as a second step if necessary. A number of rest and stress single-photon emission CT myocardial perfusion imaging, ventilation-perfusion scanning, aortic and chest MR angiographic, and more specific x-ray and abdominal examinations may be appropriate as a third layer of testing, whereas MRI of the heart or coronary arteries and invasive testing such as transesophageal echocardiography or selective coronary angiography are not considered appropriate in these patients. Given the low risk of these patients, it is mandated to minimize radiation exposure as much as possible using advanced and appropriate testing protocols. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Triage of patients with suspected coronary artery disease using multislice computed tomography

RATIONALE AND OBJECTIVES

Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization.

MATERIALS AND METHODS

A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123).

RESULTS

Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P = .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P < .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment.

CONCLUSIONS

MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based.

Usefulness of multislice spiral computed tomography coronary angiography in patients with acute chest pain in the emergency department

BACKGROUND

Despite reports that multislice spiral computed tomography (MSCT) has high sensitivity and specificity in preselected patient populations, the routine clinical feasibility and utility of MSCT coronary angiography in patients with acute chest pain in the emergency department remains uncertain.

OBJECTIVES

We sought to determine whether 16-slice MSCT coronary angiography can provide diagnostically useful images in patients with acute chest pain in the emergency department.

METHODS

Ninety-eight patients in the emergency department (41 men, 57 women; mean age +/- SD, 48.1 +/- 11.9 y) with acute chest pain underwent MSCT coronary angiography. Coronary calcium (Agatston) scoring was performed, followed by contrast-enhanced MSCT. Images were evaluated for mean image quality (MIQ) and for degree of stenosis. These data were correlated with body mass index (BMI; in kg/m(2)), heart rate, beat-to-beat variation, and calcium score to assess their influence on image quality.

RESULTS

The 28 patients (29%) with nondiagnostic MIQs had significantly higher BMIs (mean +/- SD, 32.9 +/- 9.1 vs 28.9 +/- 6.7; P < 0.05) and heart rates (mean +/- SD, 71.0 +/- 11.9 beats/min vs 65.6 +/- 9.9 beats/min; P < 0.05) than patients with diagnostic MIQs. Forty-five patients (46%) had at least 1 nondiagnostic coronary segment. These patients had significantly higher heart rates (mean +/- SD, 70.5 +/- 10.3 vs 64.1 +/- 13.7; P < 0.05) than patients with only diagnostic-quality scans. Image quality correlated inversely and strongly with BMI and heart rate.

CONCLUSIONS

Sixteen-slice MSCT coronary angiography cannot routinely provide diagnostically useful images in patients with acute chest pain in the emergency department.

New acquisition method to exclusively enhance the left side of the heart by a small amount of contrast material achieved by multislice computed tomography with 64 data acquisition system

PURPOSE

To exclusively enhance the left side of the heart by a small amount of contrast material (CM) using rapid acquisition of multislice computed tomography (MSCT) with a 64-data acquisition system (DAS).

MATERIALS AND METHODS

Forty consecutive subjects underwent MSCT (Light Speed VCT, GE) with 0.625mm slice thickness to evaluate coronary arteries. We first measured transit time, using 8ml of CM followed by 20ml saline. Dependent upon transit time, total volume of CM was determined, ranging from 45 to 63ml. After injection of CM at a rate of 4ml/s, followed by 47ml saline at 3.5ml/s, ECG-gated MSCT scanning was performed. The mean and standard deviation (S.D.) of CT values of the right atrium (RA), right ventricle (RV), left atrium (LA), left ventricle (LV), ascending aorta (Ao) and each coronary artery were measured.

RESULTS

The mean of the CT values of the RA, RV, LA, LV, Ao, right coronary artery, left main, left anterior descending branch, and left circumflex branch were 225+/-76, 251+/-72, 353+/-55, 355+/-51, 352+/-34, 312+/-65, 296+/-57, 285+/-55, and 267+/-60HU, respectively. The corresponding S.D.s of the CT values were 39+/-22, 37+/-16, 32+/-7, 31+/-8HU, 25+/-5, 36+/-15, 31+/-13, 36+/-23, and 40+/-18HU, respectively. The mean of CT values of the RA and RV were significantly lower than those of the LA, LV, Ao, and each coronary artery (P<0.01), with excellent S.D.s. We could easily obtain three-dimensional coronary arterial and LV images without artifact of the RA and RV.

CONCLUSIONS

Using 64-DAS MSCT, we successfully obtained exclusive enhancement of the left side of the heart using a small amount of CM.

Elderly Women Diagnosed with Nonspecific Chest Pain May Be at Increased Cardiovascular Risk

BACKGROUND

Women are more likely than men to have nonspecific chest pain (NSCP) symptoms. The long-term outcomes in women discharged with a diagnosis of NSCP are unknown.

METHODS

The Women's Health Initiative Observational Study enrolled postmenopausal women aged 50-79 years. After excluding those with prior cardiovascular disease (CVD), 83,622 women were studied. NSCP cases were defined as having an initial primary hospital discharge diagnosis of NSCP (ICD-9 codes 786.50, 786.51, 786.59) without a prior diagnosis of coronary heart disease (CHD). Risks of subsequent CHD events were estimated from Cox proportional hazard ratio (HR) models stratified by clinic and adjusted for baseline age, cardiovascular risk factors, and hormone use.

RESULTS

Over an average of 8 years of follow-up, 11% (230 of 2,092) of women with NSCP experienced a cardiovascular event compared with 9.5% (7,724 of 81,530) who did not. Compared with women without a hospitalization for NSCP during follow-up, those with NSCP had a greater than 2-fold higher risk of a subsequent hospitalization for clinically diagnosed angina (HR 2.18, 95% CI 1.66-2.86) and at least a 1.5-fold higher risk of nonfatal myocardial infarction (MI) (HR 1.59, 1.10-2.31), revascularization (HR 1.67, 1.28-2.20), and congestive heart failure (HR 1.75, 1.27-2.41). Women with NSCP who subsequently experienced a CHD event were more likely to be over age 65 or to have cardiovascular risk factors.

CONCLUSIONS

Older women discharged with a diagnosis of NSCP may be at increased risk of CHD morbidity. Further research is needed to replicate these findings in other populations.

Imaging of left main coronary artery dissection with multislice computed tomography

We occurred in a left main (LM) dissection during primary coronary intervention in a 45-year-old man with anterior acute myocardial infarction. Successful, multiple direct stenting was performed from the ostial to the mid left anterior descending coronary artery (LAD). Nonetheless, an LM dissection involving the proximal circumflex artery (Cx) was still evident at the end of the intervention. Multislice Computed Tomography (MSCT) coronary angiography images showed that LM dissection was definitely long and close to the ostium; moreover, the proximal stent had both excluded the false lumen in the LAD and stabilized the dissection towards the Cx. Two months later, at MSCT coronary angiography the LM dissection was still evident and the patient had remained totally asymptomatic. MSCT coronary angiography can be recommended as a complementary diagnostic tool for the assessment of LM anatomy because of the possibility of three-dimensional reconstructions and consequent clear evaluation of its take-off, course and bifurcation.

Virtual Contrast for Coronary Vessels Based on Level Set Generated Subvoxel Accurate Centerlines

We present a tool for tracking coronary vessels in MRI scans of the human heart to aid in the screening of heart diseases. The vessels are identified through a single click inside each vessel present in a standard orthogonal view. The vessel identification results from a series of computational steps including eigenvalue analysis of the Hessian of the MRI image followed by a level set-based extraction of the vessel centerline. All identified vessels are highlighted using a virtual contrast agent and displayed simultaneously in a spherical curved reformation view. In cases of over segmentation, the vessel traces can be shortened by a click on each vessel end point. Intermediate analysis results of the vessel computation steps can be displayed as well. We successfully validated the tool on 40 MRI scans demonstrating accuracy and significant time savings over manual vessel tracing.