Identification of Coronary Artery Calcification and Diagnosis of Coronary Artery Disease by Abdominal CT: A Resident Education Continuous Quality Improvement Project

Incidental Coronary Artery Calcification and Stroke Risk in Patients With Atrial Fibrillation

OBJECTIVE. Atrial fibrillation (AF) is a major risk factor for stroke. The CHA₂DS_2-VASc score is used to risk stratify patients, and the score includes known coronary artery disease (CAD) as a variable. The aim of this study was to assess if the presence of incidental coronary artery calcification (CAC), without known CAD, is associated with stroke independent of CHA₂DS₂-VASc variables. MATERIALS AND METHODS. A retrospective review of health records was performed for patients who had AF, a chest CT scan performed within 1 year, and a subsequent visit for stroke. Patients with CAD and other vascular disease, a mechanical valve, or who were older than 74 years old were excluded. Included patients were one-to-one matched by age and CHA₂DS₂-VASc risk factors to patients who had had similar follow-up but who did not have a stroke. Nongated CT images were reviewed for CAC. Univariate and Cox regression analyses were performed. RESULTS. A total of 203 patients met the study criteria, and 203 matched patients without stroke were identified. Median age was 61 years old with stroke and 62 years old without stroke (p = 0.99). In both groups, 82 (39.0%) were women and the median CHA₂DS₂-VASc was 2 (interquartile range, 1-2). Anticoagulation medication was prescribed to 46 (22.7%) patients in the group who had had a stroke and 52 (25.6%) in the group without stroke (p = 0.49). On Cox regression analysis, CAC was associated with stroke (hazard ratio [HR], 1.47; 95% CI, 1.10-1.97; p < 0.01) and mortality (adjusted HR, 1.41; 95% CI, 1.02-1.95; p = 0.04). CONCLUSION. Patients with AF and incidental CAC depicted on chest CT have an increased risk of stroke and mortality beyond established risk factors.

Coronary Artery Involvement in Segmental Arterial Mediolysis: A Case Report

Segmental arterial mediolysis (SAM) is an increasingly recognized disorder affecting small- to medium-sized muscular arteries. A patient with SAM involving the visceral arteries who was also found to have multivessel coronary artery involvement is described. The patient underwent a battery of biochemical, imaging, and genetic tests to exclude other vasculitides and connective tissue disorders. The aim is to shed light on the potential for SAM to affect the coronary arteries and recommend screening of the coronary arteries of patients with SAM. © RSNA, 2019.

Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans

Coronary artery calcification (CAC) provides an objective measure of coronary artery disease and can readily be identified on non-gated computed tomography (CT) scans with a high correlation with gated cardiac CT scans. This standardized protocol takes a step-wise approach to not only optimizing an image for the identification of calcification but also to distinguishing CAC from other common causes of calcification in the cardiac silhouette. Recognition of CAC on non-gated CT scans helps to identify a very powerful prognostic factor that can influence therapeutic interventions or downstream diagnostic testing without requiring a gated cardiac scan. These non-gated CT scans are often acquired as part of the routine care of the patient, and this data is readily available without another dose of ionizing radiation. This protocol allows for the precise and accurate extraction of this data for the purposes of retrospective data analysis in clinical research studies, but also in the clinical evaluation and management of patients.

Versatile effects of magnesium hydroxide nanoparticles in PLGA scaffold-mediated chondrogenesis

Artificial scaffolds made up of various synthetic biodegradable polymers have been reported to have many advantages including cheap manufacturing, easy scale up, high mechanical strength, convenient manipulation, and molding into an unlimited variety of shapes. However, the synthetic biodegradable polymers still have the insufficiency for cartilage regeneration owing to their acidic degradation products. To reduce acidification by degradation of synthetic polymers, we incorporated magnesium hydroxide (MH) nanoparticles into porous polymer scaffold not only to effectively neutralize the acidic hydrolysate but also to minimize the structural disturbance of scaffolds. The neutralization effect of poly(D,L-lactic-co-glycolic acid; PLGA)/MH scaffold was confirmed with the maintenance of neutral pH, contrary to a PLGA scaffold with low pH. Further, the scaffolds were applied to evaluate the chondrogenic differentiation of the human bone marrow mesenchymal stem cells. In in vitro study, the PLGA/MH scaffold enhanced the chondrogenesis markers and reduced the calcification, compared to the PLGA scaffold. Additionally, the PLGA/MH scaffold reduced the release of inflammatory cytokines, compared to the PLGA scaffold, as the cell death decreased. Moreover, the addition of MH reduced necrotic cell death at the early stage of chondrogenic differentiation. Further, the necrotic cell death by the PLGA scaffold was mediated by cleavage of caspase-1, the so-called interleukin 1-converting enzyme, and MH alleviated it as well as nuclear factor kappa B expression. Furthermore, the PLGA/MH scaffold highly supported chondrogenic healing of rat osteochondral defect sites in in vivo study. Therefore, it was suggested that a synthetic polymer scaffold containing MH could be a novel healing tool to support cartilage regeneration and further treatment of orthopedic patients.

STATEMENT OF SIGNIFICANCE

Synthetic polymer scaffolds have been widely utilized for tissue regeneration. However, they have a disadvantage of releasing acidic products through degradation. This paper demonstrated a novel type of synthetic polymer scaffold with pH-neutralizing ceramic nanoparticles composed of magnesium hydroxide for cartilage regeneration. This polymer showed pH-neutralization property during polymer degradation and significant enhancement of chondrogenic differentiation of mesenchymal stem cells. It reduced not only chondrogenic calcification but also release of proinflammatory cytokines. Moreover, it has an inhibitory effect on necrotic cell death, particularly caspase-1-mediated necrotic cell death (pyroptosis). In in vivo study, it showed higher healing rate of the damaged cartilage in a rat osteochondral defect model. We expected that this novel type of scaffold can be effectively applied to support cartilage regeneration and further treatment of orthopedic patients.

Coronary artery calcification predicts cardiovascular complications after sepsis

PURPOSE

Sepsis is a highly prevalent and fatal condition, with reported cardiovascular event rates as high as 25-30% at 1year. Risk stratification in septic patients has been extremely limited.

MATERIAL AND METHODS

267 septic patients with detectable troponin levels, APACHE II scores, and CT scans of the chest or abdomen were assessed. Patients with a recent cardiac intervention were excluded. Coronary artery calcification (CAC) was identified as present or absent on body CT scans. Cardiovascular death, acute myocardial infarction (AMI), or PCI at 1year was assessed using multivariate logistic regression analysis.

RESULTS

Patients with CAC were older, predominantly male with more risk factors for coronary disease, but similar peak troponin levels and APACHE II scores. In a multivariate analysis, CAC was predictive of the primary outcome (OR 6.827; 95% CI 1.336-54.686; p=0.037). Patients with no CAC, history of CHF or CKD were at low risk (<1%) for cardiovascular complications at 1year even at very high troponin levels (<8.0ng/dL).

CONCLUSION

CAC risk stratifies septic patients for cardiovascular complications better than traditional risk factors and can be identified on body CT scans. This novel, risk stratifying framework built on CAC can help guide individualized management of septic patients.

High pitch third generation dual-source CT: Coronary and cardiac visualization on routine chest CT

BACKGROUND

Chest CT scans are frequently performed in radiology departments but have not previously contained detailed depiction of cardiac structures.

OBJECTIVES

To evaluate myocardial and coronary visualization on high-pitch non-gated CT of the chest using 3rd generation dual-source computed tomography (CT).

METHODS

Cardiac anatomy of patients who had 3rd generation, non-gated high pitch contrast enhanced chest CT and who also had prior conventional (low pitch) chest CT as part of a chest abdomen pelvis exam was evaluated. Cardiac image features were scored by reviewers blinded to diagnosis and pitch. Paired analysis was performed.

RESULTS

3862 coronary segments and 2220 cardiac structures were evaluated by two readers in 222 CT scans. Most patients (97.2%) had chest CT for oncologic evaluation. The median pitch was 2.34 (IQR 2.05, 2.65) in high pitch and 0.8 (IQR 0.8, 0.8) in low pitch scans (p < 0.001). High pitch CT showed higher image visualization scores for all cardiovascular structures compared with conventional pitch scans (p < 0.0001). Coronary arteries were visualized in 9 coronary segments per exam in high pitch scans versus 2 segments for conventional pitch (p < 0.0001). Radiation exposure was lower in the high pitch group compared with the conventional pitch group (median CTDIvol 10.83 vs. 12.36 mGy and DLP 790 vs. 827 mGycm respectively, p < 0.01 for both) with comparable image noise (p = 0.43).

CONCLUSION

Myocardial structure and coronary arteries are frequently visualized on non-gated 3rd generation chest CT. These results raise the question of whether the heart and coronary arteries should be routinely interpreted on routine chest CT that is otherwise obtained for non-cardiac indications.