CMR-based T1-mapping offers superior diagnostic value compared to longitudinal strain-based assessment of relative apical sparing in cardiac amyloidosis.

Cardiac amyloidosis (CA) is an infiltrative disease. In the present study, we compared the diagnostic accuracy of cardiovascular magnetic resonance (CMR)-based T1-mapping and subsequent extracellular volume fraction (ECV) measurement and longitudinal strain analysis in the same patients with (a) biopsy-proven cardiac amyloidosis (CA) and (b) hypertrophic cardiomyopathy (HCM). N = 30 patients with CA, N = 20 patients with HCM and N = 15 healthy control patients without relevant cardiac disease underwent dedicated CMR studies. The CMR protocol included standard sequences for cine-imaging, native and post-contrast T1-mapping and late-gadolinium-enhancement. ECV measurements were based on pre- and post-contrast T1-mapping images. Feature-tracking analysis was used to calculate 3D left ventricular longitudinal strain (LV-LS) in basal, mid and apical short-axis cine-images and to assess the presence of relative apical sparing. Receiver-operating-characteristic analysis revealed an area-under-the-curve regarding the differentiation of CA from HCM of 0.984 for native T1-mapping (p < 0.001), of 0.985 for ECV (p < 0.001) and only 0.740 for the "apical-to-(basal + midventricular)"-ratio of LV-LS (p = 0.012). A multivariable logistical regression analysis showed that ECV was the only statistically significant predictor of CA when compared to the parameter LV-LS or to the parameter "apical-to-(basal + midventricular)" LV-RLS-ratio. Native T1-mapping and ECV measurement are both superior to longitudinal strain measurement (with assessment of relative apical sparing) regarding the appropriate diagnosis of CA.

Economic Importance of Hydatid Cyst in Slaughtered Cattle of Mugla Province

Objective: This study was carried out to investigate the prevalence, seasonal distribution and economic effects of hydatid cyst infection in slaughtered cattle of Mugla province. Methods: Data from the 2019 records of the Mugla Metropolitan Municipal Abattoir were studied retrospectively. Both direct and indirect calculation methods were used to determine the economic losses incurred due to hydatid cyst. Results: Twenty-one out of 9.985 (0.21%) cattle were found to have been infected with hydatid cyst in 2019. The highest prevelance of infection was reported in February (1.17%), while no cases were observed in May, June and August. The direct economic loss attributed to liver destruction in Mugla province was 11,760 TL (1.950 $). The total indirect economic loss caused by hydatid cyst (carcass loss, milk production loss, decreased fecundity) was 122,691 TL (20,346 $). Cumulatively, the direct and indirect economic losses for hydatid cyst disease in Mugla province were 134,451 TL (22,296 $). Conclusion: According to our results, the prevalence of hydatid cyst in cattle of Mugla province was 0.21%, which was still lower than the average loss in Turkey in spite of the corresponding significant economic loss.

Data-driven personalization of a physiologically based pharmacokinetic model for caffeine: A systematic assessment.

Physiologically based pharmacokinetic (PBPK) models have been proposed as a tool for more accurate individual pharmacokinetic (PK) predictions and model-informed precision dosing, but their application in clinical practice is still rare. This study systematically assesses the benefit of using individual patient information to improve PK predictions. A PBPK model of caffeine was stepwise personalized by using individual data on (1) demography, (2) physiology, and (3) cytochrome P450 (CYP) 1A2 phenotype of 48 healthy volunteers participating in a single-dose clinical study. Model performance was benchmarked against a caffeine base model simulated with parameters of an average individual. In the first step, virtual twins were generated based on the study subjects' demography (height, weight, age, sex), which implicated the rescaling of average organ volumes and blood flows. The accuracy of PK simulations improved compared with the base model. The percentage of predictions within 0.8-fold to 1.25-fold of the observed values increased from 45.8% (base model) to 57.8% (Step 1). However, setting physiological parameters (liver blood flow determined by magnetic resonance imaging, glomerular filtration rate, hematocrit) to measured values in the second step did not further improve the simulation result (59.1% in the 1.25-fold range). In the third step, virtual twins matching individual demography, physiology, and CYP1A2 activity considerably improved the simulation results. The percentage of data within the 1.25-fold range was 66.15%. This case study shows that individual PK profiles can be predicted more accurately by considering individual attributes and that personalized PBPK models could be a valuable tool for model-informed precision dosing approaches in the future.

Diagnostic value of the novel CMR parameter "myocardial transit-time" (MyoTT) for the assessment of microvascular changes in cardiac amyloidosis and hypertrophic cardiomyopathy.

BACKGROUND: Coronary microvascular dysfunction (CMD) is present in various non-ischemic cardiomyopathies and in particular in those with left-ventricular hypertrophy. This study evaluated the diagnostic value of the novel cardiovascular magnetic resonance (CMR) parameter "myocardial transit-time" (MyoTT) in distinguishing cardiac amyloidosis from other hypertrophic cardiomyopathies. METHODS: N = 20 patients with biopsy-proven cardiac amyloidosis (CA), N = 20 patients with known hypertrophic cardiomyopathy (HCM), and N = 20 control patients without relevant cardiac disease underwent dedicated CMR studies on a 1.5-T MR scanner. The CMR protocol comprised cine and late-gadolinium-enhancement (LGE) imaging as well as first-pass perfusion acquisitions at rest for MyoTT measurement. MyoTT was defined as the blood circulation time from the orifice of the coronary arteries to the pooling in the coronary sinus (CS) reflecting the transit-time of gadolinium in the myocardial microvasculature. RESULTS: MyoTT was significantly prolonged in patients with CA compared to both groups: 14.8 ± 4.1 s in CA vs. 12.2 ± 2.5 s in HCM (p = 0.043) vs. 7.2 ± 2.6 s in controls (p < 0.001). Native T1 and extracellular volume (ECV) were significantly higher in CA compared to HCM and controls (p < 0.001). Both parameters were associated with a higher diagnostic accuracy in predicting the presence of CA compared to MyoTT: area under the curve (AUC) for native T1 = 0.93 (95% confidence interval (CI) = 0.83-1.00; p < 0.001) and AUC for ECV = 0.95 (95% CI = 0.88-1.00; p < 0.001)-compared to the AUC for MyoTT = 0.76 (95% CI = 0.60-0.92; p = 0.008). In contrast, MyoTT performed better than all other CMR parameters in differentiating HCM from controls (AUC for MyoTT = 0.93; 95% CI = 0.81-1.00; p = 0.003 vs. AUC for native T1 = 0.69; 95% CI = 0.44-0.93; p = 0.20 vs. AUC for ECV = 0.85; 95% CI = 0.66-1.00; p = 0.017). CONCLUSION: The relative severity of CMD (measured by MyoTT) in relationship to extracellular changes (measured by native T1 and/or ECV) is more pronounced in HCM compared to CA-in spite of a higher absolute MyoTT value in CA patients. Hence, MyoTT may improve our understanding of the interplay between extracellular/intracellular and intravasal changes that occur in the myocardium during the disease course of different cardiomyopathies.

Assessment of Optic Nerve Sheath Diameter in Patients Undergoing Epiduroscopy.

BACKGROUND Epiduroscopy is commonly used for the evaluation and treatment of low back pain. Saline with or without local anesthetic addition was used to visualize epidural space structure during this procedure. A rapid increase in epidural space pressure is transmitted into the spinal space to the optic nerve sheath. This study aimed to estimate the effects of epiduroscopy on optic nerve sheath diameter (ONSD) according to the volume of fluid using the ultrasonographic measurement of optic nerve diameter in adult patients. MATERIAL AND METHODS Sixty patients who had been treated for low back pain with epiduroscopy using low-volume (LV) or high-volume (HV) fluid application were enrolled into the study. Measurement of ONSD was performed before (T0) and immediately after epiduroscopy (T1), at 10 min (T2), and 20 min (T3) after the epiduroscopy. RESULTS Both groups showed significant differences over time in ONSD (PGroup×Time=0.001). The HV group showed greater changes from T0 to T2 and T3 than the LV group in ONSD. However, in both groups, ONSDs at T2 and T3 were significantly larger than those with the highest values at T2 compared to T0. CONCLUSIONS Ultrasonography of ONSD presents a good level of diagnostic accuracy for identifying epidural hypertension. In the clinical decision-making phase, this may help physicians to be more cautious about volume when performing epidural injections to treat this disease.

Diagnostic value of global myocardial perfusion reserve assessment based on coronary sinus flow measurements using cardiovascular magnetic resonance in addition to myocardial stress perfusion imaging.

AIMS: Myocardial perfusion reserve (MPR) is defined as the maximal possible increase in myocardial blood flow (MBF) above baseline conditions. Global MBF can be measured non-invasively by means of coronary sinus flow velocity encoded cine (VENC) cardiovascular magnetic resonance (CMR). We aimed to explore the relationship between global MBF/MPR and the extent and severity of coronary artery disease (CAD) in patients referred for CAD work-up by adenosine-stress CMR. METHODS AND RESULTS: Fifty-eight patients with suspected obstructive CAD underwent both adenosine-stress CMR and invasive coronary angiography. In addition to standard cine- and late gadolinium enhancement (LGE)-imaging, first-pass myocardial perfusion imaging (MPI) and coronary sinus flow measurements (VENC) were performed at rest and during peak stress (after 140 µg/kg/min adenosine), respectively. Nineteen young patients with a very low CAD pre-test probability and normal adenosine-stress CMR formed the control group. Fifty-nine percent (n = 34) of the study group showed segmental, adenosine-induced myocardial perfusion defects compared to none of the control group (P < 0.001). Global MPR was lower in the study group compared to the control group: 2.3 (1.5-3.1) vs. 3.1 (2.0-4.3), P = 0.016. The SYNTAX score was higher in the study group patients with an impaired MPR (<2) compared to those with a preserved MPR (3.0 vs. 16.0, P = 0.01)-mainly due to higher prevalence of proximal epicardial stenoses (60% vs. 27%, P = 0.02) and multi-vessel disease (56% vs. 24%, P = 0.017). The diagnostic yield of stress CMR for the diagnosis of CAD (>50% stenosis) increased from 65to 88% when global MPR assessment was considered in addition to MPI (P = 0.025). CONCLUSIONS: Global MBF and MPR values correlate with the anatomical extent and complexity of CAD and increase the diagnostic yield of non-invasive stress CMR in the work-up of CAD. CMR-based MBF and MPR measurements may play a future role in the evaluation of the total ischaemic burden-particularly in patients with multi-vessel disease.

Determinants of health expenditure in OECD countries: A decision tree model.

OBJECTIVE: This study aimed to identify the major variables in the estimation of health expenditure in OECD member countries with the decision tree method and to categorize the member countries by health expenditure. METHODS: The study population comprised the 2014 data of the 35 OECD countries. In the study, health expenditure as a share of gross domestic product was the dependent variable while gross domestic product per capita, percentage of total population covered by public and private insurance, out-of-pocket health expenditure as percentage of total expenditure on health, age dependency ratio, life expectancy at birth, number of hospitals per million population, number of physicians per 1000 population/head counts, pharmaceutical sales and perceived health status were designated as independent variables. The decision tree model was constructed with the CART algorithm using the Orange data mining software package. RESULTS: In the study, GDP per capita, life expectancy at birth, age dependency ratio, number of hospitals and percentage of the population with a bad perceived health status were identified as the major variables in the estimation of health expenditure. OECD countries were categorized in 6 groups according to the decision tree model. According to the CART algorithm used in the model, the classification accuracy rate and the precision of estimation were computed as 80.56% and 81.25%, respectively. CONCLUSION: The study results revealed that the most important determinant for estimating the share of GDP allocated to health expenditure was GDP per capita. Future studies should be conducted with the inclusion of different variables in the model.

Morphological Assessment of Cadaveric Radial, Brachial and Subclavian Arteries: A Neurointerventional Approach.

OBJECTIVE: The transradial catheterization (TRC) is becoming widespread, primarily for neurointerventions. Therefore, the evaluation of radial artery puncture in clinical practice and a better understanding of the anatomy are important to improve the safety of neuroendovascular surgery. METHODS: Ten formalin-fixed adult Korean cadavers were dissected to expose radial artery (RA), brachial artery (BrA) and subclvian artery (ScA), bilaterally. Vessel lengths and diameters were meaured using a caliper and distance between the specific point of vessels and the anatomical landmarks including the radial styloid process, the medial epicondyle of the humerus, the sternoclavicular joint, and the vertebral artery orifice were also measured. RESULTS: The average length between the radial (RAPS) and the BrA puncture sites (BrAPS) and between the vertebral artery orifice (VAO) and the BrA bifurcation (BrAB) did not differ between sides (p>0.05). The average length between the radial styloid process (RSP) and the RAPS was 13.41±2.19 mm, and the RSP was 26.85±2.47 mm from the median nerve (MN). The mean length between the medial epicondyle (ME) and the BrAPS as 44.23±5.47 mm, whereas the distance between the ME and the MN was 42.23±4.77 mm. The average VAO-ScA angle was 70.94±6.12°, and the length between the ScA junction (SCJ) and the VAO was 60.30±8.48 mm. CONCLUSION: This study provides basic anatomical information about the radial artery and the brachial route and can help improving new techniques, selection of size and shape of catheters for TRC. This can help neurointerventionists who adopt a transradial neuroendovascular approach and offers comprehensive and safe care to their patients.

Magnetic resonance of the heart in a muscular dystrophy patient with an MR conditional ICD: assessment of safety, diagnostic value and technical limitations.

Cardiovascular magnetic resonance (CMR) studies in patients with pacemakers or implantable cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. Therefore, in the last years the manufacturers developed not only MR-conditional pacemakers, but also MR-conditional ICDs. However, the clinical experience regarding the feasibility and limitations of MR studies of the heart in patients with ICDs is still limited. In particular, there are hardly any CMR studies in the same patients performed prior to and post ICD implantation allowing a one-to-one comparison of the obtained CMR images. This is the first presentation of a CMR study in a patient with the world's first and so far only MR-conditional ICD. In our case, a major problem related to the presence of the MR conditional ICD was an image artifact caused by the device's generator which hampered the visualization of the midventricular and apical anterior and antero-lateral segments in all sequences performed. Considering previous studies, right chest implantation of the ICD could probably have helped in this setting and may be preferred in future ICD implantations. Our case report nicely illustrates the real clinical need for specially designed implantable devices that ensure safe and high-quality imaging in patients in whom serial CMR is required.