Coronary computed tomography angiography-based coronary risk stratification in subjects presenting with no or atypical symptoms.

BACKGROUND: Coronary computed tomography angiography (CTA) findings of positive vessel remodeling and low-attenuation plaque, referred to as computed tomography-verified high-risk plaque (CT-HRP), have been reported to be associated with the development of subsequent acute coronary syndromes. The aim of this study was to examine the usefulness of coronary CTA for coronary risk re-stratification of patients with asymptomatic and atypical chest symptoms. METHODS AND RESULTS: A total of 1,139 subjects (M/F 602/537; mean age, 61.5±9.3 years) who were either asymptomatic or presented with atypical chest symptoms underwent coronary 64- or 320-slice multidetector computed tomography angiography and Agatston score. Age, sex, coronary risk factors, including hypertension, diabetes mellitus (DM), dyslipidemia, and smoking were investigated as predictors for CT-HRP on multivariate analysis using logistic regression analysis. CT-HRP was observed in 72 patients (6.3%). Based on Framingham risk scores (FRS), CT-HRP was observed in 0/94 subjects (0.0%) in the low-risk group, 35/806 (4.3%) in the intermediate-risk group, and 37/239 (15.5%) in the high-risk group. On logistic regression analysis significant predictors for CT-HRP in intermediate- and high-risk subjects were male sex (odds ratio [OR] 2.829; 95% confidence interval [CI] 1.460-5.479, P=0.0021), DM (OR 2.418; 95% CI 1.420-4.116, P=0.0011), and current smoking (OR 1.922; 95% CI 1.096-3.371, P=0.0160). CT-HRP prevalence for Agatston scores >500 and >250 was lower in the intermediate- and high-risk groups, respectively. CONCLUSIONS: In asymptomatic subjects and those presenting with atypical chest pain who have a more than an intermediate risk, coronary CTA is contributory to FRS. Male sex, DM and smoking were independent predictors of vulnerable plaque in the more than intermediate-risk group.

Prevalence of anomalous origin of coronary artery detected by multi-detector computed tomography at one center.

BACKGROUND: Anomalous origin of coronary artery (AOCA) has been described by coronary angiography or autopsy. However the actual prevalence of such abnormalities is unknown. Multi-detector computed tomography (MDCT) offers the possibility to visualize AOCA non-invasively. The purpose of this study was to report the prevalence AOCA by MDCT. METHODS AND RESULTS: In 5869 consecutive subjects who underwent coronary MDCT (Aquilion 64, Toshiba Medical Systems Corporation, Otowara, Japan) at one center, the prevalence of AOCA was 89 (1.52%) patients. The most common abnormality (33 cases, 0.56%) was the origin of the coronary artery or branch from the opposite or non-coronary sinus. The right coronary arteries (RCA) arising from the left coronary artery sinus (LCS) was observed in 27 cases (0.46%). Vascular cross-sectional area of such RCA arising from LCS was significantly smaller in 11 patients with angina than in 10 patients without symptoms [3.02 (1.68-7.67) mm² vs 5.93 (2.54-12.04) mm² p < 0.05]. The left coronary artery arising from the non-coronary sinus was observed in 2 cases (0.03%), and the left anterior descending coronary artery (LAD) or left circumflex coronary artery (LCX) arising from the right coronary sinus was observed in 4 cases (0.07%). Single coronary arteries were found in 5 cases (0.09%). Fifteen patients (0.26%) presented multiple coronary ostia, all of 15 (0.26%) had the LAD and LCX separately arising from the left coronary sinus. High take off was found in 36 cases (0.60%). CONCLUSION: MDCT can accurately detect and characterize the type of AOCA.

[What factors affected image quality in coronary multidetector-row computed tomography?].

BACKGROUND: Although it is well known that we usually cannot acquire a high quality coronary MDCT in patients with arrhythmia or incomplete breath-hold, we sometimes also cannot obtain a high quality coronary MDCT in patients without arrhythmia or incomplete breath-hold. PURPOSE: We studied what factors other than arrhythmia or incomplete breath-hold affected image quality. METHODS: Coronary MDCT and echocardiography were performed within one month in 2145 patients, and 452 cases of arrhythmia or 102 cases of incomplete breath-hold during scanning were eliminated. The remaining 1591 patients were studied. Those patients were divided into two groups (mid-diastolic phase reconstruction (MD) group (N=1377) and end-systolic phase reconstruction (ES) group (N=214)). Age, body weight, mean heart rate (HR) during scanning, temporal resolution (TR) and left ventricular ejection fraction (LVEF) by echocardiography were estimated. Image quality (A: Excellent (3 points), B: Acceptable (2 points), C: Unacceptable (1 point)) was evaluated. RESULTS: The mean image quality points of the MD group (2.9±0.3) were significantly (P<0.0001) higher than the mean image quality points of the ES group (2.3±0.7), and the mean HR of the MD group (57±6 bpm) was significantly (P<0.0001) lower than that of the ES group (81±15 bpm). In the MD group, HR and TR were selected as significant factors affecting image quality by stepwise regression analysis. In the ES group, TR and HR were selected. In the ES subgroup with HR<90 bpm, TR and HR were selected; however, in the ES subgroup with HR≥90 bpm, TR and LVEF were selected. CONCLUSION: In the MD group, low HR was important for high quality coronary MDCT. In the ES subgroup with HR<90, short TR and low HR were important; however, in the ES subgroup with HR≥90 bpm, TR and LVEF were more important than HR.

Significance of PQ interval in acquisition of coronary multidetector row computed tomography.

BACKGROUND: Since image quality obtained in the mid-diastolic [or slow filling (SF)] phase is generally superior to end-systolic image in coronary multidetector row computed tomography (MDCT), low heart rate (HR) comprises the most important factor for acquisition of high-quality images. However, despite HR <70 and optimum breath-hold, sometimes high quality images cannot be obtained in SF. We assessed the significance of PQ interval in acquisition of coronary MDCT. METHODS AND RESULTS: Of 541 consecutive patients who underwent coronary MDCT, 7 patients with incomplete breath-hold, 62 HR ≥70, and 70 arrhythmias were excluded. The remaining 402 patients (M: 222, 66±11 years), including 38 with first-degree atrioventricular block (1° AVB, PQ >200 ms) were evaluated. RR and PQ were measured on electrocardiogram and systolic and SF phase with 4-chamber cine cardiac computed tomography. SF significantly (p<0.0001) correlated with RR (SF=-471+0.720RR, r=0.887) in all subjects. The SF of without 1° AVB (292±97 ms) was significantly (p<0.0147) longer than that of with 1° AVB (251±121 ms), although RR was not significantly different between the two groups. The SF/RR of without 1° AVB (27.2±6.1%) was also significantly (p<0.0001) higher than that of with 1° AVB (22.7±8.0%). The coefficient of correlation between (RR-PQ) and SF [r=0.915, p<0.0001, SF=-362+0.742(RR-PQ)] was significantly (p<0.034) higher than that of correlation between RR and SF in all subjects. The SF of rank A image quality was significantly longer than that of rank B (p<0.0001) or rank C (p=0.0042). In critical HR (60-69 bpm), the optimum phase was ES in 7/139 patients without 1° AVB, and SF in 3/13 patients with 1° AVB (chi(2), p<0.0416). CONCLUSION: Since SF depends on (RR-PQ), if PQ is long in critical HR, it might be difficult to reconstruct high quality images in the SF phase.

ECG-edit function in multidetector-row computed tomography coronary arteriography for patients with arrhythmias.

BACKGROUND: ECG-gating is necessary for cardiac computed tomography, but is not suitable for arrhythmias, so the aim of this study was to evaluate the usefulness of the ECG-edit function for this purpose. METHODS AND RESULTS: Of 1,221 patients undergoing 64-row multidetector-row computed tomography coronary angiography (coronary MDCT), 123 patients (28 atrial fibrillation (Af), 39 premature atrial contractions (PAC), 42 premature ventricular contractions (PVC), 3 PAC + PVC, 10 sinus arrhythmias (SA), and a second-degree atrioventricular block (2 degrees AVB)) had arrhythmias necessitating the ECG-edit function. Short R-R interval was deleted and mid-diastolic phases were selected from the long R-R intervals using the "R+absolute time" method. In the present study, the reconstructed images were evaluated using a triple-grade scale A-C, representing excellent, acceptable, and unacceptable image quality. Image quality, categorized as A, B and C, respectively, was 50%, 36% and 14% for the 28 patients with Af; 56%, 36% and 8% for the 39 PAC patients, and 65%, 33% and 2% in the 42 PVC patients. None of the scans of the PAC + PVC, SA, and 2 degrees AVB patients was ranked as C. CONCLUSIONS: The ECG-edit function is useful for reconstructing coronary MDCT images in many arrhythmias, and provides clinically acceptable images in most cases.

Inappropriate secretion of antidiuretic hormone in a patient with chronic inflammatory demyelinating polyneuropathy.

A 54-year-old man suffered from a relapse of chronic inflammatory demyelinating polyneuropathy (CIDP), and developed quadriplegia and somnolence requiring mechanical ventilation for respiratory failure. Serum Na concentration remained at low levels during the clinical course, and a diagnosis of inappropriate secretion of antidiuretic hormone (SIADH) was made. The present case had not only acute aggravation of CIDP with autonomic dysfunction but also intracranial hypertension caused by increased CSF protein (maximum level, 1,315 mg/dl). It seemed likely that injury of the afferent fibers of the baroregulatory pathway or intracranial hypertension might have contributed to SIADH in this patient.