Multislice spiral computed tomographic angiography of coronary arteries in patients with suspected coronary artery disease: an effective filter before catheter angiography?

BACKGROUND: Despite impressive image quality, it is unclear if noninvasive coronary angiography with multislice spiral computed tomography (CT) is powerful enough to act as a filter before invasive angiography (INV-A) in symptomatic patients. METHODS AND RESULTS: We therefore studied 133 consecutive symptomatic patients with suspected coronary artery disease (CAD) and an indication for INV-A (chest pain and signs of ischemia in conventional stress tests). Patients with known CAD, acute coronary syndrome, or a calcium volume score >1000 were excluded. In all patients, both INV-A and multislice CT angiography (MSCT-A) (Philips MX 8000 multislice spiral CT, scan time 250 milliseconds, slice thickness 1.3 mm, 120 mL of contrast agent, 4 mL/s, retrospective gating) were directly compared by 2 independent investigators using the American Heart Association 15-segment model. Altogether, we studied 1596 segments, 74% had diagnostic image quality. Multislice CT angiography correctly identified 68 significant stenoses of the 75 stenoses seen with INV-A (sensitivity 91%). In 945 of 1185 diagnostic segments, stenosis could correctly be ruled out with MSCT-A. There were 3 times more stenoses seen with MSCT-A compared with INV-A (positive predictive value 29%) mainly because of misclassification of nonobstructive plaques as stenosis. The per-patient analysis allowed to exclude significant CAD in 42 (32%) of 133 patients. In only 6 of 53 patients, MSCT-A failed to detect significant stenosis, 4 of those were in small segments not requiring intervention. Calcium scoring alone was less suited as a filter before angiography: 25 patients (18% of study group) had a calcium score = 0, and 8 of these patients turned out to have significant stenoses. CONCLUSION: Multislice CT angiography, but not calcium scoring alone, offers promise to reduce the number of INV-A in symptomatic patients with suspected CAD by up to one third with minimal risk for the patient.

T wave spectral variance for noninvasive identification of patients with idiopathic dilated cardiomyopathy prone to ventricular fibrillation even in the presence of bundle branch block or atrial fibrillation.

Conventional methods using Holter ECG recordings for noninvasive risk stratification are limited in patients with idiopathic dilated cardiomyopathy (IDC) prone to ventricular fibrillation (VF) having atrial fibrillation (AF) or bundle branch block (BBB). We therefore investigated, whether spectral assessment of beat-to-beat alternations of repolarization is associated with VF in these patients. Twenty-four-hour Holter ECG recordings in 462 patients with IDC were used. The VF group comprised of 64 consecutive patients who survived cardiac arrest, the no VF group consisted of 398 consecutive patients without a history of malignant ventricular arrhythmia. One hundred patients with ischemic cardiomyopathy (ICM) served as a control group. In each patient, 1,024 consecutive T waves were aligned using cross correlation methods. Two-dimensional Fourier transform (2D FFT) used the data matrix of 1,024 consecutive 200-ms segments centered to the T wave peak. Power spectra of the 2D FFT revealed the frequency content of the T wave in the first dimension and the periodicity of this frequency content in the second dimension. The ratio between periodic frequency contents and the sum of nonperiodic and periodic frequency contents between 0.5 and 50 Hz is equal to the T wave spectral variance (TWSV) index. Thus, TWSV index = 0 would mean that all 1,024 T waves are identical and TWSV index = 1 would mean that the 1,024 T waves are totally variable. The TWSV index was significantly higher in the VF group (0.93 +/- 0.14) than in the no VF group (0.53 +/- 0.13, P < 0.01). The best cutoff between the VF and the no VF group was achieved by using a TWSV index of 0.75 (sensitivity = 89%, specificity = 78%). No significant differences were observed between patients with and without AF or with and without BBB, and between patients with IDC and ICM. Even in the presence of BBB or AF spectral assessment of T wave alternations by TWSV index using 2D FFT in Holter ECG recordings, allows the identification of patients with IDC at risk for VF.

[Invasive versus noninvasive (MSCT) coronary angiography. Importance of cardiac diagnostics with multislice computed tomography]. / Invasive versus nichtinvasive (MSCT) Koronarangiographie. Stellenwert der kardialen Diagnostik mittels Multislice-Computertomographie.

Cardiac imaging with fast computed tomography (CT) is a quickly evolving field starting to become established in the cardiac routine work-up. The exclusion of coronary calcification is the most accurate noninvasive method to exclude significant coronary stenosis whereas the detection of calcification identifies coronary arteriosclerosis. The total calcium load correlates with the risk of coronary stenosis, but there is not a 1 : 1 relationship. CT angiography with contrast enhancement offers promises to increase diagnostic accuracy. 4-slice scanners acquire data with a slide width down to 1 mm. The spatial resolution of invasive coronary angiography cannot be achieved yet. Severe coronary stenosis may be excluded with 90% specificity if image quality is not impaired by artifacts, severe calcification, arrhythmia, and a heart rate > 70 beats/min. With present technology, about 26% of segments may not be adequately assessed. Despite these limitations CT angiography is a useful tool to reduce the number of invasive diagnostic angiography. In patients with known coronary artery disease (CAD), progression as well as stent occlusion can be assessed. Instent stenosis can only be diagnosed indirectly. The patency of arterial and venous grafts can be assessed very well including also the bypass insertion site. Actual studies on the significance of noncalcified plaques are in progress.A CT angiography should take place in order to avoid further exposure to radiation. Therefore, patients with typical angina or significant signs of coronary ischemia have to be investigated by invasive methods and do not profit from a CT scan. Preparation and implementation of this method should only be applied in cooperation with radiologists and cardiologists in an experienced center.

Interventional treatment of giant pseudoaneurysm with subsequent decompression of internal mammaria bypass.

We present a case of a 38-year-old patient with angina after direct current (DC) cardioversion. The patient's medical history included documented coronary heart disease with interventional treatment of the LAD and RCA followed by emergency CABG 6 months ago. On recent admission, the coronary angiography revealed a giant pseudoaneurysm of the left descending coronary artery complicated by compression of LIMA. The pseudoaneurysm was successfully treated with three stent grafts.

Postinfarction risk assessment for sudden cardiac death using late potential analysis of the digital Holter electrocardiogram.

INTRODUCTION: Noninvasive postinfarction risk assessment for sudden cardiac death is limited. Standard analysis of the signal-averaged QRS complex can identify patients at risk for monomorphic ventricular tachycardia, but its value for discriminating patients at risk for sudden death is low. METHODS AND RESULTS: The aim of this study was to prospectively investigate repeated late potential analysis of digital Holter ECG and compare it with standard analysis of the signal-averaged QRS complex within a short ECG period and with common clinical risk factors for sudden cardiac death in 756 consecutive patients after acute myocardial infarction. Digital Holter ECG were subdivided into 5-minute segments, and late potential analysis was performed on each 5-minute segment. During follow-up of 32 +/- 15 months, 35 patients died of sudden cardiac death and 50 patients died of nonsudden cardiac death. Sudden cardiac death was associated with ejection fraction < 40%, nonsustained ventricular tachycardia, creatine kinase > 1,000 IU/L, and late potentials in > 75% of analyzed Holter ECGs (abnormal LP75), but not with late potentials determined by only a short ECG period. According to multivariate analysis, the best independent significant predictor of sudden cardiac death was abnormal LP75 (P = 0.002, sensitivity 29%, specificity 96%, positive predictive value 40%, negative predictive value 97%). Nonsudden cardiac death was associated with ejection fraction < 40% (P = 0.001). CONCLUSIONS: Late potential analysis of digital Holter ECG is a powerful tool that can be used to determine postinfarction patients at risk for sudden cardiac death and is optimized when combined with determination of ejection fraction.