Computerized tomographic angiography (3D data representing the coronary arteries) and X-ray angiography (2D X-ray image sequences providing information about coronary arteries and their stenosis) are standard and popular assessment tools utilized for medical diagnosis of coronary artery diseases. At present, the results of both modalities are individually analyzed by specialists and it is difficult for them to mentally connect the details of these two techniques. The aim of this work is to assist medical diagnosis by providing specialists with the relationship between computerized tomographic angiography and X-ray angiography.
The new 64-row multidetector computed tomography (CT)-assisted angiography can now detect coronary artery disease with shorter breath-hold time and at faster heart rates for symptomatic patients. We aim to determine if the 64-row scanner can also overcome limitations due to mild to moderate calcification.
This study is conducted to investigate and compare image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated coronary CT angiography (CCTA) with the use of single-source CT (SSCT) and dual-source CT (DSCT).
OBJECTIVE: Overt and subclinical hypothyroidism are risk factors for atherosclerosis. It is unclear whether thyroid hormone levels within the normal range are also associated with atherosclerosis measured by coronary artery calcium (CAC).
APPROACH AND RESULTS: We conducted a cross-sectional study of 41 403 apparently healthy young and middle-aged men and women with normal thyroid hormone levels. Free thyroxin, free triiodothyronine, and thyroid-stimulating hormone levels were measured by electrochemiluminescent immunoassay. CAC score was measured by multidetector computed tomography. The multivariable adjusted CAC ratios comparing the highest versus the lowest quartile of thyroid hormones were 0.74 (95% confidence interval, 0.60-0.91; P for trend <0.001) for free thyroxin, 0.81 (0.66-1.00; P for trend=0.05) for free triiodothyronine, and 0.78 (0.64-0.95; P for trend=0.01) for thyroid-stimulating hormone. Similarly, the odds ratios for detectable CAC (CAC >0) comparing the highest versus the lowest quartiles of thyroid hormones were 0.87 (0.79-0.96; P for linear trend <0.001) for free thyroxin, 0.90 (0.82-0.99; P for linear trend=0.02) for free triiodothyronine, and 0.91 (0.83-1.00; P for linear trend=0.03) for thyroid-stimulating hormone.
CONCLUSIONS: In a large cohort of apparently healthy young and middle-aged euthyroid men and women, low-normal free thyroxin and thyroid-stimulating hormone were associated with a higher prevalence of subclinical coronary artery disease and with a greater degree of coronary calcification.
KEYWORDS: thyroid hormones; thyrotropin; thyroxine; triiodothyronine
Coronary heart disease is a major health problem in Malaysia with high morbidity and mortality. Common primary screening tool of cardiovascular risk stratification is exercise treadmill test (ETT). This communication is to determine the performance of coronary artery calcium score a new method to stratify the presence of obstructive coronary artery disease (CAD) in comparison to traditional ETT in patients having coronary artery diseases.
A retrospective analysis was performed in patients undergoing prospective ECG-triggered coronary computed tomography (CT) angiography (CCTA) with the single-source 64-slice CT (SSCT), dual-source 64-slice CT (DSCT), dual-source 128-slice CT and 320-slice CT with the aim of comparing the radiation dose associated with different CT generations. A total of 164 patients undergoing prospective ECG-triggered CCTA with different types of CT scanners were studied with the mean effective doses estimated at 6.8 ± 3.2, 4.2 ± 1.9, 4.1±0.6 and 3.8 ± 1.4 mSv corresponding to the 128-slice DSCT, 64-slice DSCT, 64-slice SSCT and 320-slice CT scanners. In this study a positive relationship was found between the effective dose and the body mass index (BMI). A low radiation dose is achieved in prospective ECG-triggered CCTA, regardless of the CT scanner generation. BMI is identified as the major factor that has a direct impact on the effective dose associated with prospective ECG-triggered CCTA.
INTRODUCTION: Rheumatoid arthritis (RA) patients who have active disease with longer disease duration have been reported to have increased risk of cardiovascular events compared to the normal population.
OBJECTIVE: The primary aim of our study is to ascertain the prevalence of significant asymptomatic coronary artery disease (CAD) in Asian RA patients who are in remission using multi-detector computed tomography (MDCT). The secondary aims of our study are the usage of pulse wave velocity and the biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-senstivity C-reactive protein (hs-CRP) to detect subclinical atherosclerosis in RA patients.
METHODS: We performed a comparative cross-sectional study of 47 RA patients who were in remission with a control group of non-RA patients with a history of atypical chest pain in Sarawak General Hospital from November 2008 to February 2009. All patients underwent 64-slice MDCT, assessment of arterial stiffness using the SphygmoCor test and blood analysis for NT-proBNP and hsCRP.
RESULTS: There were 94 patients in our study with a mean age of 50 +/- 8.8 years. The RA and control patients in each group were matched in terms of traditional CV risk factors. Our RA patients had a median disease duration of 3 years (IQR 5.5). MDCT showed evidence of CAD in nine (19.1%) RA patients and three (6.4%) control patients (P = 0.06). There was no significant association between pulse wave velocity (PWV) and presence of CAD in our RA group. There was no significant correlation between PWV with levels of proBNP or hsCRP in our RA patients.
CONCLUSIONS: In our current pilot study with the limitation of small sample size, RA was not associated with an increased risk of CAD in our RA patients who were in remission. Larger studies of CAD in Asian RA patients are needed to confirm our current finding.
Study site: Sarawak General Hospital, Kuching, Sarawak, Malaysia