1.
Coronary calcium score improves the estimation for pretest probability of obstructive coronary artery disease and avoids unnecessary testing in individuals at low extreme of traditional risk factor burden: validation and comparison of CONFIRM score and genders extended model.
Wang, M, Liu, Y, Zhou, X, Zhou, J, Zhang, H, Zhang, Y
BMC cardiovascular disorders. 2018;(1):176
Abstract
BACKGROUND Reliability of models for estimating pretest probability (PTP) of obstructive coronary artery disease (CAD) has not been investigated in individuals at low extreme of traditional risk factor (RF) burden. Thus, we sought to validate and compare CONFIRM score and Genders extended model (GEM) among these individuals. METHODS We identified symptomatic individuals with 0 or 1 RF who underwent coronary calcium scan and coronary computed tomographic angiography (CCTA). Follow-up clinical data were also recorded. PTP of obstructive CAD for every individual was estimated according to CONFIRM score and GEM, respectively. Area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), net reclassification improvement (NRI) and Hosmer-Lemeshow (H-L) test were used to assess the performance of models. RESULTS There were 1201 individuals with 0 RF and 2415 with 1 RF. The AUC for GEM was significantly larger than that for CONFIRM score, no matter in individuals with 0 (0.843 v.s. 0.762, p < 0.0001) or 1 (0.823 v.s. 0.752, p < 0.0001) RF. Compared to CONFIRM score, GEM demonstrated positive IDI (5% in individuals with 0 RF and 8% in individuals with 1 RF), positive NRI (41.50% in individuals with 0 RF and 40.19% in individuals with 1 RF), better prediction of clinical events and less discrepancy between observed and predicted probabilities, resulting in a significant decrease of unnecessary testing, especially in negative individuals. CONCLUSION In individuals at low extreme of traditional RF burden of CAD, the addition of coronary calcium score provided a more accurate estimation for PTP and application of GEM instead of CONFIRM score could avoid unnecessary testing.
2.
Non-HDL-C is a Better Predictor for the Severity of Coronary Atherosclerosis Compared with LDL-C.
Zhang, Y, Wu, NQ, Li, S, Zhu, CG, Guo, YL, Qing, P, Gao, Y, Li, XL, Liu, G, Dong, Q, et al
Heart, lung & circulation. 2016;(10):975-81
Abstract
BACKGROUND Recent guidelines recommended both low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) are the primary target of lipid modulating therapy. However, which lipid measure is most closely related to the severity of coronary atherosclerosis has not yet been assessed. METHODS We studied 1757 consecutive subjects undergoing coronary angiography who were not receiving any lipid-lowering therapy. Low-density lipoprotein cholesterol was measured directly, and non-HDL-C was calculated. The severity of coronary stenosis was determined using the Gensini Score (GS) system. RESULTS In the overall population, LDL-C and non-HDL-C were all dramatically increased according to the quartiles of GS (p<0.001, both). In patients with coronary atherosclerosis (n=1097), non-HDL-C (r=0.138, p<0.001) was more closely related to GS than LDL-C (r=0.113, p<0.001) tested by Spearman correlation analysis. Multivariate logistic regression analysis suggested that non-HDL-C (OR=1.326, 95% CI 1.165-1.508, p<0.001) was slightly superior to LDL-C (OR=1.286, 95% CI 1.130-1.463, p<0.001) in predicting high GS after adjusting for potential confounders. Among patients with LDL-C less than the median, discordant non-HDL-C could not provide extra value in predicting high GS (OR=0.759, 95% CI 0.480-1.201). However, among patients with LDL-C greater than or equal to the median, the cardiovascular risk was overestimated for patients with discordant non-HDL-C (OR=0.458, 95% CI 0.285-0.736). CONCLUSIONS Our data support the use of non-HDL-C ahead of LDL-C in predicting the severity of coronary atherosclerosis, especially among patients with LDL-C greater than or equal to the median.
3.
Radiation and contrast agent doses reductions by using 80-kV tube voltage in coronary computed tomographic angiography: a comparative study.
Cao, JX, Wang, YM, Lu, JG, Zhang, Y, Wang, P, Yang, C
European journal of radiology. 2014;(2):309-14
Abstract
OBJECTIVE To investigate the effects of 80-kilovoltage (kV) tube voltage coronary computed tomographic angiography (CCTA) with a reduced amount of contrast agent on qualitative and quantitative image quality parameters and on radiation dose in patients with a body mass index (BMI) <23.0 kg/m(2). METHODS One hundred and twenty consecutive patients with a BMI <23.0 kg/m(2) and a low calcium load undergoing retrospective electrocardiogram (ECG)-gated dual-source CCTA were randomized into two groups [standard-tube voltage (120-kV) vs. low-tube voltage (80-kV)]. The injection flow rate of contrast agent (350 mg I/mL) was adjusted to body weight of each patient (4.5-5.5 mL/s in the 120-kV group and 2.8-3.8 mL/s in the 80-kV group). Radiation and contrast agent doses were evaluated. Quantitative image quality parameters and figure of merit (FOM) of coronary artery were evaluated. Each coronary segment was evaluated for image quality on a 4-point scale. RESULTS Compared with the 120-kV group, effective dose and amount of contrast agent in the 80-kV group were decreased by 57.8% and 30.5% (effective dose:2.7 ± 0.5 vs. 6.4 ± 1.3 mSv; amount of contrast agent:57.1 ± 3.2 vs. 82.1 ± 6.1 mL; both p<0.0001), respectively. Image noise was 22.7 ± 2.1HU for 120-kV images and 33.2 ± 5.2 HU for 80-kV images (p<0.0001). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the proximal right coronary artery (RCA) and left main coronary artery (LMA) were all lower in 80-kV than 120-kV images (SNR in the proximal RCA: 16.5 ± 1.8 vs. 19.4 ± 2.8; SNR in the LMA: 16.3 ± 2.0 vs.19.6 ± 2.7; CNR in the proximal RCA: 19.4 ± 2.3 vs.22.9 ± 3.0; CNR in the LMA: 18.8 ± 2.4 vs. 22.7 ± 2.9; all p<0.0001). FOM were all significantly higher in 80-kV than 120-kV images (proximal RCA: 146.7 ± 45.1 vs. 93.4 ± 32.0; LMA: 139.1 ± 47.2 vs. 91.6 ± 31.1; all p<0.0001). There was no significant difference in image quality score between the two groups (3.3 ± 0.8 vs. 3.3 ± 0.8, p=0.068) despite decreased SNR and CNR of coronary artery in the 80-kV group. CONCLUSION The 80-kV protocol significantly reduces radiation and contrast agent doses in CCTA in patients with a low BMI <23.0 kg/m(2) and a low calcium load while maintaining image quality.