Collateral non cardiac findings in clinical routine CT coronary angiography: results from a multi-center registry.

PURPOSE: The aim of the study was to evaluate the prevalence of collateral findings detected in computed tomography coronary angiography (CTCA) in a multi-center registry. MATERIALS AND METHODS: We performed a retrospective review of 4303 patients (2719 males, mean age 60.3 ± 10.2 years) undergoing 64-slice CTCA for suspected or known coronary artery disease (CAD) at various academic institutions between 01/2006 and 09/2010. Collateral findings were recorded and scored as: non-significant (no signs of relevant pathology, not necessary to be reported), significant (clear signs of pathology, mandatory to be reported), or major (remarkable pathology, mandatory to be reported and further investigated). RESULTS: We detected 6886 non-cardiac findings (1.6 non cardiac finding per patient). Considering all centers, only 865/4303 (20.1 %) patients were completely without any additional finding. Overall, 2095 (30.4 %) non-significant, 4486 (65.2 %) significant, and 305 (4.4 %) major findings were detected. Among major findings, primary lung cancer was reported in 21 cases. In every center, most prevalent significant findings were mediastinal lymph nodes >1 cm. In 256 patients, collateral findings were clinically more relevant than coexisting CAD and justified the symptoms of patients. CONCLUSIONS: The prevalence of significant and major collateral findings in CTCA is high. Radiologists should carefully evaluate the entire scan volume in each patient.

Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: a 24-month follow-up study.

The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5 +/- 10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque < or =50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries.

Relationship between plasma nitric oxide concentration and insulin resistance in essential hypertension.

BACKGROUND: Plasma nitric oxide (NOx) concentrations in patients with essential hypertension (EH) have been reported to be higher, lower, or no different than in normotensives. This study was initiated to determine whether these inconsistent findings were related to differences in insulin resistance. METHODS: Fasting plasma NOx and insulin concentrations were measured in 78 patients with EH and the relationship between these variables evaluated by regression analysis. Patients with hypertension were also divided into tertiles based on their fasting plasma insulin concentration: the highest tertile classified as insulin resistant (EH-IR) and the lowest as insulin sensitive (EH-IS). Plasma NOx concentrations were compared among these two groups and a third group of 21 normotensive, insulin resistant (N-IR) individuals by one-way ANOVA. RESULTS: Plasma insulin and NOx concentrations were correlated (r = 0.31, P <.01) in patients with hypertension, independently of differences in age, body mass index, waist circumference, and blood pressure. Plasma NOx concentrations were different in the three experimental groups (P <.001), being significantly higher (P <.05) in the EH-IR than in either of the other two groups. Despite being hyperinsulinemic, NOx levels in N-IR individuals were lower than in EH-IR subjects and no different from EH-IS individuals. CONCLUSIONS: Plasma NOx concentrations are highest in those patients with EH who are also insulin resistant/hyperinsulinemic (EH-IR). Furthermore, because plasma NOx concentrations were as high in the EH-IS as in the N-IR populations, it could be speculated that plasma NOx concentrations are also modulated by EH, per se.

The impact of training on diagnostic accuracy with computed tomography coronary angiography.

AIM: The aim of this study is to assess the image quality and diagnostic accuracy of computed tomography (CT) coronary angiography (CTCA) in different hospital settings with the same trained team. MATERIALS AND METHODS: Four hundred patients were consecutively enrolled for CTCA in a large academic hospital (Group 1; Sensation 64 Cardiac, Siemens - Iomeprol 400, Bracco; 200 patients) and in a small local hospital (Group 2; VCT, GE Healthcare - Iodixanol 320, GE Healthcare; 200 patients). All patients were enrolled for suspected coronary artery disease (CAD) and patients with stents or who had previously undergone coronary bypass were excluded. Scan protocols (retrospectively ECG-gated; no dose reduction modulation applied) were performed in accordance with standards reported in the international literature with the best solution available on site. Image quality was assessed in each coronary segment with a 4-point Likert scale: 0, not assessable; 1, low; 2, average; 3, good. Diagnostic accuracy was calculated against conventional coronary angiography with a threshold of at least 50% for significant stenosis. RESULTS: There was no significant difference between demographics, BMI, prevalence of obstructive CAD, calcium score and heart rate between the two populations. The average image quality was 2.83 ± 0.37 for Group 1 and 2.86 ± 0.31 for Group 2 (P > 0.05). Per-segment sensitivity, specificity, positive and negative predictive values were 92.6% (87-95), 97.9% (97-98), 75.9% (69-81) and 99.5% (99-99), respectively, for Group 1, and 90.4% (85-93), 98.6% (98-99), 84.2% (78-88) and 99.2% (98-99), respectively, for Group 2 (P > 0.05). CONCLUSION: There is no significant difference in image quality and diagnostic accuracy of CTCA when the investigation is performed by the same properly trained team. CTCA is a robust imaging modality for the detection of coronary artery stenosis.

Plaque imaging with CT coronary angiography: Effect of intra-vascular attenuation on plaque type classification.

AIM: To assess the attenuation of non-calcified atherosclerotic coronary artery plaques with computed tomography coronary angiography (CTCA). METHODS: Four hundred consecutive patients underwent CTCA (Group 1: 200 patients, Sensation 64 Cardiac, Siemens; Group 2: 200 patients, VCT GE Healthcare, with either Iomeprol 400 or Iodixanol 320, respectively) for suspected coronary artery disease (CAD). CTCA was performed using standard protocols. Image quality (score 0-3), plaque (within the accessible non-calcified component of each non-calcified/mixed plaque) and coronary lumen attenuation were measured. Data were compared on a per-segment/per-plaque basis. Plaques were classified as fibrous vs lipid rich based on different attenuation thresholds. A P < 0.05 was considered significant. RESULTS: In 468 atherosclerotic plaques in Group 1 and 644 in Group 2, average image quality was 2.96 ± 0.19 in Group 1 and 2.93 ± 0.25 in Group 2 (P ≥ 0.05). Coronary lumen attenuation was 367 ± 85 Hounsfield units (HU) in Group 1 and 327 ± 73 HU in Group 2 (P < 0.05); non-calcified plaque attenuation was 48 ± 23 HU in Group 1 and 39 ± 21 HU in Group 2 (P < 0.05). Overall signal to noise ratio was 15.6 ± 4.7 in Group 1 and 21.2 ± 7.7 in Group 2 (P < 0.01). CONCLUSION: Higher intra-vascular attenuation modifies significantly the attenuation of non-calcified coronary plaques. This results in a more difficult characterization between lipid rich vs fibrous type.

Insulin resistance/compensatory hyperinsulinemia predict carotid intimal medial thickness in patients with essential hypertension.

BACKGROUND AND AIM: Approximately 50% of subjects with essential hypertension (EH) are insulin resistant, and this defect in insulin action could contribute to increased cardiovascular disease (CVD) risk in these patients. To test this hypothesis, we attempted to see if there was a link between insulin resistance (IR) and carotid intimal medial thickness (IMT), an early index of CVD, in patients with essential hypertension. METHODS AND RESULTS: Ultrasound quantification of carotid IMT was performed in 79 hypertensive patients, and 63 patients (31 m and 32 f), defined as being free of plaque (IMT < 1.3 mm), were further subdivided into normal (<1.0 mm) and thickened (1-1.3 mm) IMT groups. Subjects in the thickened IMT group were older and had significantly (p < 0.05) higher plasma concentrations of fasting insulin, nitric oxide (NO(x)) and intercellular adhesion molecule 1 (ICAM-1). However, the two groups were not significantly different in terms of blood pressure, overall or regional obesity, fasting lipid levels, uric acid, concentrations of other cellular adhesion molecules or levels of C-reactive protein. There were significant (p < 0.05) correlations in the whole population between IMT and age, fasting insulin and NO(x), and multiple regression analysis identified fasting insulin as an independent predictor of IMT. CONCLUSIONS: The presence of increased IMT is significantly related to several metabolic and endothelial abnormalities associated with IR/hyperinsulinemia, and fasting insulin independently predicts the thickness of the intima-media layer. These results support the view that CVD risk is greatest in those patients with essential hypertension who are also IR/hyperinsulinemic.