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Background: Iodinated contrast is commonly used for radiological procedures, with one dose delivering several hundred-fold the daily requirements needed for normal thyroid hormone production. Risks of excess iodine include incident thyroid dysfunction, which is associated with adverse cardiac outcomes, yet there are no prospective studies investigating the changes in cardiac physiology following iodine contrast administration. This study was conducted to investigate the longitudinal relationships between the amount of iodinated contrast administration and changes in cardiac electrophysiology and structure. Methods: A longitudinal cohort study was conducted with prospectively enrolled participants who received iodine contrast for elective computed tomography or coronary angiography. Serum thyroid function tests, electrocardiograms (EKG), and transthoracic echocardiograms were obtained serially until 36 months. Trends of electrical and structural cardiac changes following iodine contrast administration were assessed using mixed effect models. Results: The cohort was composed of 129 patients (median age, 70 [interquartile range: 63, 75] years; 98% male). Larger amounts of iodine exposure were associated with increases in QRS and QTc durations and decreased ejection fraction (EF), and these associations were still observed for follow-up EF after additionally adjusting for baseline values (the high-iodine contrast group vs. the low-iodine contrast group, −4.23% [confidence interval, −7.66% to −0.79%]). Dose–response analyses also showed lower EF with larger amounts of iodine received; these trends were not significant for the EKG parameters studied. Conclusions: Over a period of up to 36 months, a larger amount of administered iodine contrast was associated with lower EF among participants. Further investigation is needed to elucidate the long-term trends of electrical and structural cardiac function after iodine contrast administration. [ABSTRACT FROM AUTHOR]

Background: Management of atrial fibrillation (AF) in very severe obese patients is challenging. Cryoballoon ablation (CBA) represents an effective rhythm control strategy. However, data in this patient group were limited. Methods: Highly symptomatic AF patients with body mass index (BMI) ≥ 40 kg/m2 who had failed antiarrhythmic drug therapy and electrocardioversion and failure to achieve targeted body‐weight‐reduction underwent CBA. Results: Data of 72 very severe obese AF patients (Group A) and 129 AF patients with normal BMI (Group B, BMI < 25 kg/m2) were consecutively collected. Group A had significantly younger age (60.6 ± 10.4 vs. 69.2 ± 11.2 years), higher BMI (44.3 ± 4.3 vs. 22.5 ± 1.6 kg/m2). Procedural pulmonary vein isolation (PVI) was successful in all patients (2 touch‐up ablation in Group A). Compared to Group B, Group A had similar procedural (61.3 ± 22.6 vs. 57.5 ± 19 min), similar fluoroscopy time (10.1 ± 5.5 vs. 9.2 ± 4.8 min) but significantly higher radiation dose (2852 ± 2095 vs. 884 ± 732 µGym2). We observed similar rates of real‐time‐isolation (78.6% vs. 78.5%), single‐shot‐isolation (86.5% vs. 88.8%), but significantly longer time‐to‐sustained‐isolation (53.5 ± 33 vs. 43.2 ± 25 s). There was significantly higher rate of puncture‐site‐complication (6.9% vs. 1.6%) in Group A. One‐year clinical success in paroxysmal AF was (Group A: 69.4% vs. Group B: 80.2%; p <.001), in persistent AF was (Group A: 58.1% vs. Group B: 62.8%; p =.889). In Re‐Do procedures Group A had a numerically lower PVI durability (75.0% vs. 83.6%, p =.089). Conclusion: For very severe obese AF patients, CBA appears feasible, leads to relatively good clinical outcome. [ABSTRACT FROM AUTHOR]

Flexible electronics have enabled catheter-based intravascular sensing. However, real-time interrogation of unstable plaque remains an unmet clinical challenge. Here, we demonstrate the feasibility of stretchable electrochemical impedance spectroscopy (EIS) sensors for endoluminal investigations in New Zealand White (NZW) rabbits on diet-induced hyperlipidemia. A parylene C (PAC)-based EIS sensor mounted on the surface of an inflatable silicone balloon affixed to the tip of an interrogating catheter was deployed (1) on the explants of NZW rabbit aorta for detection of lipid-rich atherosclerotic lesions, and (2) on live animals for demonstration of balloon inflation and EIS measurements. An input peak-to-peak AC voltage of 10 mV and sweeping-frequency from 300 kHz to 100 Hz were delivered to the endoluminal sites. Balloon inflation allowed EIS sensors to be in contact with endoluminal surface. In the oxidized low-density-lipoprotein (oxLDL)-rich lesions from explants of fat-fed rabbits, impedance magnitude increased significantly by 1.5-fold across the entire frequency band, and phase shifted ~5° at frequencies below 10 kHz. In the lesion-free sites of the normal diet-fed rabbits, impedance magnitude increased by 1.2-fold and phase shifted ~5° at frequencies above 30 kHz. Thus, we demonstrate the feasibility of stretchable intravascular EIS sensors for identification of lipid rich lesions, with a translational implication for detecting unstable lesions.

Abstract Background The need of having feasible screening tools like Coronary Calcium Scoring (CCS) and CT Coronary Artery (CTCA) for Coronary Artery Disease (CAD) has become paramount. We aimed to evaluate the accuracy of CCS in determining the degree of stenosis of coronary vessels as compared to that determined by CTCA in a South Asian population. Methods A retrospective study was conducted at The Aga Khan University Hospital. A total of 539 patient records were reviewed who had undergone CCS and CTCA between 2008 and 2010. Patient records were reviewed by comparing their CCS and CTCA results. Results About 268 out of 301 (89%) patients with a CCS of 0–9 were found to be free of stenosis on CTCA. On a CCS of 10–99, 110 out of 121 (91%) patients were either free of stenosis or had mild stenosis. About 66 out of 79 (84%) patients had moderate or severe stenosis with a calcium score of 100–400 while none of the patients were free of stenosis. Around 28 out of 38 (74%) patients with a CCS of more than 400 had severe stenosis. However, only 04 patients (11%) were found to have mild stenosis. Spearman’s rho revealed a correlation coefficient of 0.791 with a p-value of

Impaired aortic distensibility index (ADI) is associated with cardiovascular risk factors. This study evaluates the relation of ADI measured by computed tomographic angiography (CTA) with the severity of coronary atherosclerosis in subjects with suspected coronary artery disease (CAD). Two hundred and twenty-nine subjects,age 63 ± 9 years, 42% female, underwent coronary artery calcium (CAC) scanning and CTA, and their ADI and Framingham risk score (FRS) were measured. End-systolic and end-diastolic (ED) cross-sectional-area(CSA) of ascending-aorta (AAo) was measured 15-mm above the left-main coronary ostium. ADI was defined as: [(Δlumen-CSA)/(lumen-CSA in ED × systemic-pulse-pressure) × 10(3)]. ADI measured by 2D-trans-thoracic echocardiography (TTE) was compared with CTA-measured ADI in 26 subjects without CAC. CAC was defined as 0, 1-100, 101-400 and 400+. CAD was defined as luminal stenosis 0, 1-49% and 50%+. There was an excellent correlation between CTA- and TTE-measured ADI (r(2)=0.94, P=0.0001). ADI decreased from CAC 0 to CAC 400+; similarly from FRS 1-9% to FRS 20% + (P

Epicardial adipose tissue (EAT), pericardial adipose tissue (PAT), and subcutaneous adipose tissue (SAT) are mediators of metabolic risk and may be involved in the pathogenesis of coronary artery disease. The aim of this study was to investigate the association of visceral and subcutaneous fat depots with the presence and severity of coronary artery calcium (CAC) in asymptomatic individuals.One hundred eleven consecutive subjects underwent CAC assessment, and their Framingham risk scores were measured. EAT, total thoracic adipose tissue, and SAT volumes were measured from slice level 15 mm above to 30 mm below the ostium of the left main coronary artery. PAT was calculated as thoracic adipose tissue - EAT. SAT was defined as the volume of fat depot anterior to the sternum and posterior to the vertebra. CAC was defined as 0, 1 to 100, 101 to 400, or ≥ 400. Relative risk regression analysis was used to assess the association between fat depots and CAC.There were modest correlations between EAT (r = 0.58), PAT (r = 0.47), SAT (r = 0.34), and CAC (P < .01). EAT, PAT, and SAT increased proportionally with the severity of CAC in both genders (P < .05). After adjustment for cardiovascular risk factors and body mass index, the relative risks for each standard deviation increase in EAT, PAT, and SAT were 3.3 (95% confidence interval, 1.9-5.6), 2.7 (95% confidence interval, 1.6-3.9), and 2.6 (95% confidence interval, 1.5-4.4) for CAC ≥ 100 compared to CAC 0, respectively (P < .05). The area under the receiver-operating characteristic curve to predict CAC ≥ 100 was higher in each fat depot compared to Framingham risk score, and addition of fat depots to Framingham risk score provided maximum prognostication value to detect CAC ≥ 100.Increased EAT, PAT, and SAT are associated with the severity of CAC independent of risk factors.

BackgroundAtorvastatin is a synthetic inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. In placebo-controlled trials, it has been shown to achieve significant dose-dependent reductions in low-density lipoprotein cholesterol, total cholesterol, and triglycerides. This trial compared the efficacy of daily atorvastatin administration with that of alternate-day dosing.MethodsThis was a randomized, prospective, nonblinded, controlled clinical trial. Fifty-four patients with low-density lipoprotein cholesterol of 100 to 200 mg/dL were enrolled. Baseline fasting lipid profile (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides), liver function tests (aspartate transaminase and alanine aminotransferase), and creatine kinase were drawn. Patients were randomized to three atorvastatin dose groups. Group I received 10 mg of atorvastatin every day, Group II received 10 mg every other day, and Group III received 20 mg every other day. After 6 weeks of treatment with atorvastatin, fasting lipid profiles, liver function tests, and creatine kinase concentrations were redrawn. Compliance to treatment was assessed at each visit.ResultsOf the 54 patients enrolled, 46 completed the study. All three regimens significantly reduced total cholesterol and low-density lipoprotein cholesterol compared to baseline. No statistically significant differences existed between the three groups in regards to total, or a percentage, decrease in total cholesterol and low-density lipoprotein cholesterol at 6 weeks compared to baseline. All regimens were well tolerated and none of the patients had a significant elevation of liver enzymes or creatine kinase during the course of the study.ConclusionAlternate-day dosing of atorvastatin is an efficacious and safe alternative to daily dosing.

In this investigation, the previously proposed phenomenological model in the literature is generalized both in terms of the mathematical form of the model and the yield function used to describe the plasticity of the material. Al 1050 is chosen as the model material, where the sheets made from this material are first annealed and then subjected to a tensile test and Erichsen cupping test to obtain tensile properties as well as the FLC of the material. The constants of the generalized model are first obtained by curve fitting, whereby in this approach least overall error is expected as a single equation is used to predict the FLC of material. Further, it is shown that it would be possible to enhance the accuracy of the model at the cost of losing the applicability of a single mathematical expression for both branches of FLC. In this approach, the generalized model would be calibrated for the right branch based on Swift's model and for the left branch based on Hill's model. Finally, the effect of the yield criterion used to describe the plasticity of the material on the predictions of the generalized model is investigated, and it is shown that using the Hosford yield criterion yields better results compared to using the von Mises yield criterion. [ABSTRACT FROM AUTHOR]

Context: Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied. Objective: To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/ flutter. Methods: Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism. Results: Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04). Conclusion: Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost–benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated. [ABSTRACT FROM AUTHOR]