Christopher Dailing

Effect of statin treatment on coronary plaque progression - a serial coronary CT angiography study.

OBJECTIVES Statins have been shown to reduce plaque progression using data on intravascular ultrasound, carotid intima-media thickness and coronary artery calcium scans. However, there is little data on effects of statins on plaque progression using Coronary CTA. The objective is to evaluate the effect of statin therapy on plaque progression using serial Coronary CTA (CCTA). METHODS The study included 100 consecutive patients who underwent serial Coronary CTA (mean follow up: 406 ± 92 days) for evaluation of CAD without known prior heart disease or revascularization. We performed volumetric assessment of low attenuation plaque (LAP < 30 Hounsfield units), non-calcified (NCP) and calcified plaque volumes at baseline and follow up scans for vessels >2 mm in diameter. Patients who received statins were compared to those that did not. RESULTS Total plaque progression was significantly reduced among statin user compared to non-statin users (-33.3 mm(3) ± 90.5 vs. 31.0 mm(3) ± 84.5, p = 0.0006). Statin users had significantly reduced progression of NCP volume (-47.7 mm(3) ± 71.9 vs. 13.8 mm(3) ± 76.6, p < 0.001) and significantly reduced progression of LAP volume (-12.2 mm(3) ± 19.2 vs. 5.9 mm(3) ± 23.1, p < 0.0001). When we compared for remodeling index, no statistical difference was found between the two groups (p = 0.25) and a non-significant trend toward calcium progression (29.3 mm(3) ± 67.9 vs. 10.0 mm(3) ± 53.2, p = 0.133). After adjustment for cardiovascular risk factors, mean plaque volume difference between statin and non-statin users was statistically significant for both LAP and NCP volumes (-18.1, 95% CI: -26.4, -9.8 for LAP; -101.7, 95% CI: -162.1, -41.4 for NCP; p < 0.001) respectively. CONCLUSION Statin therapy resulted in significantly lower progression of LAP and NCP plaques compared to non-statin users.

Measurement of Phantomless Thoracic Bone Mineral Density on Coronary Artery Calcium CT Scans Acquired with Various CT Scanner Models

PURPOSE To determine the accuracy and precision of thoracic phantomless bone mineral density (BMD) measurements obtained on coronary artery calcium (CAC) computed tomography (CT) scans by using a variety of commercially available CT scanners. MATERIALS AND METHODS The institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. A total of 4126 asymptomatic subjects (2022 [49%] men, 2104 [51%] women; mean age, 63.7 years ± 11.8 [standard deviation]) underwent CAC CT with the use of a quantitative CT calibration phantom for evaluation of subclinical atherosclerosis. Two hundred eighty subjects also underwent CT of the chest, abdomen, and pelvis (C7 through L5). Mean BMD of three consecutive thoracic vertebrae (in the T7-T10 range) was measured in all 4126 subjects. Individual calibration factors for each phantom insert and a general calibration factor for the spine were determined for each CT scanner model. The study population was then divided into three subgroups: All calibration factors were generated from group 1 (n = 1536) and were applied and tested in group 2 (n = 1587), and effects of various image acquisition parameters were assessed in group 3 (n = 1003). Accuracy (bias) and precision of thoracic phantomless BMD measurements across 14 CT scanner models from five manufacturers were determined. RESULTS Phantomless BMD values correlated highly with standard phantom-based quantitative CT BMD values (r = 0.987, P < .001). Bias was 3.9% ± 1.4 for phantomless BMD measurements, and the mean coefficient of variation for the general calibration factor was 4.9% ± 2.4. CONCLUSION Phantomless BMD can be measured accurately on CAC CT scans acquired with a variety of CT scanners without additional radiation exposure.

Aged Garlic Extract Reduces Low Attenuation Plaque in Coronary Arteries of Patients with Metabolic Syndrome in a Prospective Randomized Double-Blind Study

BACKGROUND Although several previous studies have demonstrated that aged garlic extract (AGE) inhibits the progression of coronary artery calcification, its effect on noncalcified plaque (NCP) has been unclear. OBJECTIVE This study investigated whether AGE reduces coronary plaque volume measured by cardiac computed tomography angiography (CCTA) in patients with metabolic syndrome (MetS). METHODS Fifty-five patients with MetS (mean ± SD age: 58.7 ± 6.7 y; 71% men) were prospectively assigned to consume 2400 mg AGE/d (27 patients) or placebo (28 patients) orally. Both groups underwent CCTA at baseline and follow-up 354 ± 41 d apart. Coronary plaque volume, including total plaque volume (TPV), dense calcium (DC), NCP, and low-attenuation plaque (LAP), were measured based upon predefined intensity cutoff values. Multivariable linear regression analysis, adjusted for age, gender, number of risk factors, hyperlipidemia medications, history of coronary artery disease, scan interval time, and baseline %TPV, was performed to examine whether AGE affected each plaque change. RESULTS The %LAP change was significantly reduced in the AGE group compared with the placebo group (-1.5% ± 2.3% compared with 0.2% ± 2.0%, P = 0.0049). In contrast, no difference was observed in %TPV change (0.3% ± 3.3% compared with 1.6% ± 3.0%, P = 0.13), %NCP change (0.2% ± 3.3% compared with 1.4% ± 2.9%, P = 0.14), and %DC change (0.2% ± 1.4%, compared with 0.2% ± 1.7%, P = 0.99). Multivariable linear regression analysis found a beneficial effect of AGE on %LAP regression (β: -1.61; 95% CI: -2.79, -0.43; P = 0.008). CONCLUSIONS This study indicates that the %LAP change was significantly greater in the AGE group than in the placebo group. Further studies are needed to evaluate whether AGE has the ability to stabilize vulnerable plaque and decrease adverse cardiovascular events. This trial was registered at clinicaltrials.gov as NCT01534910.

EFFECT OF STATIN TREATMENT ON CORONARY PLAQUE PROGRESSION: A SERIAL CT ANGIOGRAPHY STUDY

Background: Statins have been shown to reduce plaque progression using data on intravascular ultrasound, carotid intimal-media thickness and coronary artery calcium scans. However, there is little data on effects of statins in regard to plaque progression using cardiac computed tomographic angiography (CCTA). In this study, we evaluated effect of statin therapy on plaque progression using serial CCTA scans.

Automated estimation of image quality for coronary computed tomographic angiography using machine learning

ObjectivesOur goal was to evaluate the efficacy of a fully automated method for assessing the image quality (IQ) of coronary computed tomography angiography (CCTA).MethodsThe machine learning method was trained using 75 CCTA studies by mapping features (noise, contrast, misregistration scores, and un-interpretability index) to an IQ score based on manual ground truth data. The automated method was validated on a set of 50 CCTA studies and subsequently tested on a new set of 172 CCTA studies against visual IQ scores on a 5-point Likert scale.ResultsThe area under the curve in the validation set was 0.96. In the 172 CCTA studies, our method yielded a Cohen’s kappa statistic for the agreement between automated and visual IQ assessment of 0.67 (p < 0.01). In the group where good to excellent (n = 163), fair (n = 6), and poor visual IQ scores (n = 3) were graded, 155, 5, and 2 of the patients received an automated IQ score > 50 %, respectively.ConclusionFully automated assessment of the IQ of CCTA data sets by machine learning was reproducible and provided similar results compared with visual analysis within the limits of inter-operator variability.Key points• The proposed method enables automated and reproducible image quality assessment.• Machine learning and visual assessments yielded comparable estimates of image quality.• Automated assessment potentially allows for more standardised image quality.• Image quality assessment enables standardization of clinical trial results across different datasets.

The relationship between cardio-ankle vascular index and subclinical atherosclerosis evaluated by cardiac computed tomographic angiography

The cardio‐ankle vascular index (CAVI) is a new noninvasive index to evaluate arterial stiffness. We investigated whether CAVI can predict severity, extent, and burden of coronary artery disease by comparing results with cardiac computed tomographic angiography (CCTA).

Changes in Coronary Plaque Volume: Comparison of Serial Measurements on Intravascular Ultrasound and Coronary Computed Tomographic Angiography

Serial measurements of coronary plaque volume have been used to evaluate drug efficacy in atherosclerotic progression. However, the usefulness of computed tomography for this purpose is unknown. We investigated whether the change in total plaque volume on coronary computed tomographic angiography is associated with the change in segment plaque volume on intravascular ultrasound. We prospectively enrolled 11 consecutive patients (mean age, 56.3 ± 5 yr; 6 men) who were to undergo serial invasive coronary angiographic examinations with use of grayscale intravascular ultrasound and coronary computed tomography, performed <180 days apart at baseline and from 1 to 2 years later. Subjects underwent 186 serial measurements of total plaque volume on coronary computed tomography and 22 of segmental plaque volume on intravascular ultrasound. We used semiautomated software to examine percentage relationships and changes between total plaque and segmental plaque volumes. No significant correlations were found between percentages of total coronary and segment coronary plaque volume, nor between normalized coronary plaque volume. However, in the per-patient analysis, there were strong correlations between the imaging methods for changes in total coronary and segment coronary plaque volume (r=0.62; P=0.04), as well as normalized plaque volume (r=0.82; P=0.002). Per-patient change in plaque volume on coronary computed tomography is significantly associated with that on intravascular ultrasound. Computed tomographic angiography may be safer and more widely available than intravascular ultrasound for evaluating atherosclerotic progression in coronary arteries. Larger studies are warranted.

Multicenter Aids Cohort Study Quantitative Coronary Plaque Progression Study: rationale and design

Background and aim The association of HIV with coronary atherosclerosis has been established; however, the progression of coronary atherosclerosis over time among participants with HIV is not well known. The Multicenter AIDS Cohort Study Quantitative Coronary Plaque Progression Study is a large prospective multicenter study quantifying progression of coronary plaque assessed by serial coronary computed tomography angiography (CTA). Patients and methods HIV-infected and uninfected men who were enrolled in the Multicenter AIDS Cohort Study Cardiovascular Substudy were eligible to complete a follow-up contrast coronary CTA 3–6 years after baseline. We measured coronary plaque volume and characteristics (calcified and noncalcified plaque including fibrous, fibrous-fatty, and low attenuation) and vulnerable plaque among HIV-infected and uninfected men using semiautomated plaque software to investigate the progression of coronary atherosclerosis over time. Conclusion We describe a novel, large prospective multicenter study investigating incidence, transition of characteristics, and progression in coronary atherosclerosis quantitatively assessed by serial coronary CTAs among HIV-infected and uninfected men.