Cardiovascular Catheterization Research Articles

Geographic Areas of Responsibility Among Percutaneous Coronary Intervention-capable Hospitals in the Philippines

Background: Defining geographic areas of responsibility sheds light on the current status of the acute coronary syndrome healthcare system and the unmet needs that will help plan for improvement. Methods: The list of registered percutaneous coronary intervention (PCI)-capable hospitals and the total members of adult interventional cardiologists per island from the Philippine Society of Cardiovascular Catheterization and Interventions as of January 2022 was used. A map was created by establishing a 120 km radius around each PCI-capable hospital, which was then employed to classify provinces as either covered, partially covered or not covered. Results: The analysis included 244 adult interventional cardiologists and 54 PCI-capable hospitals. Luzon registered the highest percentage of interventional cardiologists (85.7%) and PCI-capable hospitals (78.9%), followed by Visayas (8.6%) and (11.5%), and Mindanao (5.7%) and (9.6%), respectively. Most PCI-capable hospitals were privately owned (79.6%) versus government owned (20.4%). The largest percentage of PCI-capable hospitals was in Metro Manila (46.3%), followed by Cebu (9.26%), Laguna and Pampanga (5.57%), Benguet, Davao del Sur, Misamis Oriental, Nueva Ecija and Iloilo (3.7%). Only 46.4% of provinces were covered; 34.1% were partially covered and 19.5% were not covered. Conclusion: Most PCI-capable hospitals in the Philippines are privately owned and centrally located on an island. There may be a need to add PCI-capable hospitals that are government owned, equally distributed and strategically placed in partially and non-covered provinces.

Characterization of patient dose distributions and probabilistic risk analysis in cardiovascular catheterization laboratories

Purpose: Patient radiation doses in cardiovascular and interventional radiology are highly variable for similar procedures. This random nature may be better described by a distribution function, compared to a linear regression. This study develops a distribution function to characterize patient dose distributions and estimate probabilistic risk. Methods: Reference air kerma from 8647 patients over six years were retrospectively collected from an EP lab and two Cath labs. Data was first sorted into low dose (<100mGy) and high dose cases (>100mGy), and histograms of the data created. Dagum and Inverse gamma distributions were chosen to initially fit to both low and high dose cases. Fits between model and the data was optimized, and a linear regression analysis performed to obtain R squared values and standard errors for the correlation between model and data. Risk probabilities were estimated according to the modeled distribution function. BMI and time distributions were analyzed to understand their influence on the inverse gamma distribution error found in the data. 75th percentiles from both descriptive statistics and model were calculated. Results: The inverse gamma distribution can be used to characterize radiation dose distributions. Model predicted cases for radiation dose 3000mGy< x <5000mGy and >5000mGy are approximately 42 and 0 for 3651 cases for lab#1, and 14 and 1 for 3197 cases for lab#2, respectively, while the actual cases are 10 and 0, and 16 and 2. Descriptive and model statistics generated different 75th percentile levels for sorted data compared to unsorted data. Time has a greater influence on inverse gamma distribution function than BMI. Conclusion: This study creates a framework to understand the random error present in radiology practices that cause wide variations in patient radiation doses. It also provides an approach to evaluate different IR areas in terms of effectiveness of dose reduction measures.

Morphological study of musculi pectinati and crista terminalis with its applied significance in the human adult cadaver

Background: Morphological studies have highlighted the roles of the crista terminalis (CT) and musculi pectinati (MP) in the process behind cardiac arrhythmias. It is also intriguing to explore the notion that structural problems with the CT and MP may be the major anomaly in those who have atrial flutter and may also account for the incidence of atrial flutter even in people with atria that appear to be normal. The aim is to study the cumulative arrangement and morphology of CT and MP in the right atrium of formalin-fixed human cadavers. Methodology: Cross-sectional descriptive research was conducted on thirty hearts obtained from formalin-embalmed adult human cadavers of the age range between 25 and 65 years (22 males and 8 females). Anatomical course, arrangements, and variations of CT and MP were observed and noted. Results: After meticulous dissection of formalin-fixed human heart, variations associated with the morphological traits of the MP and taenia sagittalis (TS) were observed and recorded. According to the gross anatomical architecture of CT and associated MP, it was classified into six various patterns. Type 1 (MP oriented nearly 90° to CT) was found to be the most common variant, exhibited by 16 (53%) hearts, Type 2 (MP oriented parallel to CT) was noted in 1 (4%), 7 (22%) shown Type 3 (combination of Type 1 and Type 2), Type 4 (branching of the MP) was noted in 2 (7%), Type 5 (interlacing trabeculation) was seen in 3 (10%), whereas Type 6 (prominent muscular column of MP) was present in 1 (4%) of the heart. In addition, the observation on TS (prominent band of MP, seen emerging from CT) was also classified into three groups – Type A (TS was absent) was noted in 15 (50%) hearts was the most common variant, Type B (single trunk of TS) was present in 3 (10%) and Type C (multiple trunks of TS) in 12 (40%) hearts. Conclusion: Cardiovascular catheterization frequently results in injury to Type 6 MP and Type B/Type C TS, which have a more intricate arrangement of fibers. Henceforth, collectively the incidence of these clinically relevant variants was a little more than 50%.

Management of Patients With Kidney Disease in Need of Cardiovascular Catheterization: A Scientific Workshop Cosponsored by the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions

<h2>Abstract</h2> Patients with chronic kidney disease (CKD) are at an increased risk of developing cardiovascular disease (CVD), whereas those with established CVD are at risk of incident or progressive CKD. Compared with individuals with normal or near normal kidney function, there are fewer data to guide the management of patients with CVD and CKD. As a joint effort between the National Kidney Foundation and the Society for Cardiovascular Angiography and Interventions, a workshop and subsequent review of the published literature was held. The present document summarizes the best practice recommendations of the working group and highlights areas for further investigation.

An interventional MRI guidewire combining profile and tip conspicuity for catheterization at 0.55T.

We describe a clinical grade, "active", monopole antenna-based metallic guidewire that has a continuous shaft-to-tip image profile, a pre-shaped tip-curve, standard 0.89 mm (0.035″) outer diameter, and a detachable connector for catheter exchange during cardiovascular catheterization at 0.55T. Electromagnetic simulations were performed to characterize the magnetic field around the antenna whip for continuous tip visibility. The active guidewire was manufactured using medical grade materials in an ISO Class 7 cleanroom. RF-induced heating of the active guidewire prototype was tested in one gel phantom per ASTM 2182-19a, alone and in tandem with clinical metal-braided catheters. Real-time MRI visibility was tested in one gel phantom and in-vivo in two swine. Mechanical performance was compared with commercial equivalents. The active guidewire provided continuous "profile" shaft and tip visibility in-vitro and in-vivo, analogous to guidewire shaft-and-tip profiles under X-ray. The MRI signal signature matched simulation results. Maximum unscaled RF-induced temperature rise was 5.2°C and 6.5°C (3.47 W/kg local background specific absorption rate), alone and in tandem with a steel-braided catheter, respectively. Mechanical characteristics matched commercial comparator guidewires. The active guidewire was clearly visible via real-time MRI at 0.55T and exhibits a favorable geometric sensitivity profile depicting the guidewire continuously from shaft-to-tip including a unique curved-tip signature. RF-induced heating is clinically acceptable. This design allows safe device navigation through luminal structures and heart chambers. The detachable connector allows delivery and exchange of cardiovascular catheters while maintaining guidewire position. This enhanced guidewire design affords the expected performance of X-ray guidewires during human MRI catheterization.

Prevention of Contrast-Induced Nephropathy After Cardiovascular Catheterization and Intervention With High-Dose Strong Statin Therapy in Japan - The PREVENT CINC-J Study.

Previous studies have reported that high-dose strong statin therapy reduces the incidence of contrast-induced nephropathy (CIN) in statin naïve patients; however, the efficacy of high-dose strong statins for preventing CIN in real-world clinical practice remains unclear. The aim of this study was to evaluate the efficacy of strong statin therapy in addition to fluid hydration for preventing CIN after cardiovascular catheterization.Methods and Results: This prospective, multicenter, randomized controlled trial included 420 patients with chronic kidney disease who underwent cardiovascular catheterization. They were assigned to receive high-dose pitavastatin (4 mg/day × 4 days) on the day before and of the procedure and 2 days after the procedure (Statin group, n=213) or no pitavastatin (Control group, n=207). Isotonic saline hydration combined with a single bolus of sodium bicarbonate (20 mEq) was scheduled for administration to all patients. In the control group, statin therapy was continued at the same dose as that before randomization. CIN was defined as a ≥0.5 mg/dL increase in serum creatinine or ≥25% above baseline at 48 h after contrast exposure. Before randomization, 83% of study participants were receiving statin treatment. The statin group had a higher incidence of CIN than the control group (3.0% vs. 0%, P=0.01). The 12-month rate of major adverse cardiovascular events was similar between the 2 groups. High-dose pitavastatin increases the incidence of CIN in this study population.

Impact of Simulation-Based Training on Radiation Exposure of Young Interventional Cardiologists

Reducing radiation exposure during cardiovascular catheterization is of paramount importance to ensure patient and staff safety. Our study aimed to assess the transferability of acquired skills from virtual reality to the real world, including radioprotection measures during mentored simulation training (ST) in coronary angiography. A total of 10 cardiology residents were evaluated during real-life cases in the catheterization laboratory before (group A) and after mentored ST. The educational effect of mentored simulator training on real-life case performance was evaluated at 2 different time points: within the first week (group B) and after 12 weeks (group C). Compared with group A, the total dose area product (DAP) (µGy•m2) and total air kerma (mGy) were lower after ST: group A: 2,633 (1,723 to 3,617) versus group B: 1,618 (1,032 to 2,562), p <0.05 and 214 (136 to 297) versus 135 (84 to 222), p <0.05, respectively. Concerning operator radiation exposure (µSv), left finger dose: 1,090 (820 to 1,460) versus 635 (300 to 900), p=0.028; left leg dose 80 (0 to 110) versus 0 (0 to 0), p=0.027; left eye lens dose: 39 (24 to 69) versus 11 (8 to 20), p <0.0001; and chest dose outside the lead apron: 50 (34 to 88) versus 29 (21 to 50), p <0.003 were significantly lower in the group B than group A. A total of 12 weeks after ST, the total DAP and total air kerma remained stable along with operator exposure except left eye lens dose (µSv): group B: 11 (8 to 20) versus group C: 16 (12 to 27), p=0.02. In addition, left eye lens dose, left wrist dose, and chest dose outside the lead apron were significantly correlated with total DAP (rs=0.635, rs=0.729, and rs=0, 629, respectively) and total air kerma (rs=0.488, rs=0.514, and rs=0.548, respectively) at 12 weeks. In conclusion, ST for coronary angiography may improve radioprotection learning and should be incorporated into training curricula.

A practical guide to setting up pig models for cardiovascular catheterization, electrophysiological assessment and heart disease research.

Over the past years, the use of large animals has become increasingly interesting in translational research, to bridge the gap between basic research in rodents and targeted therapies in humans. Pigs are highly valued in cardiovascular research because of their anatomical, hemodynamic and electrophysiological features, which closely resemble those of humans. For studying these aspects in swine, cardiac catheterization techniques are essential procedures. Although cardiac catheterization seems to be comparatively easy in pigs as human equipment can be used to perform the procedure, there are some pitfalls. Here we provide a detailed protocol to guide the reader through different aspects of cardiac catheterization in pigs. We suggest an approach for safe intubation and extubation, provide tips for perioperative and postoperative management of the animals and guide the reader through different experimental steps, including sheath insertion. We also describe the procedures for basic electrophysiological assessment of conduction properties and atrial fibrillation induction, hemodynamic assessment via pressure-volume loops, right heart and left heart catheterization and the development of a myocardial infarction model by balloon occlusion. This protocol was developed in Landrace pigs and can be adapted to other pig breeds or other large animal species. This protocol requires approximately six and a half working hours in total and should be performed by researchers with previous experience in large animal experimentation and in the presence of a veterinarian.

Improved catheter tracking during cardiovascular magnetic resonance-guided cardiac catheterization using overlay visualization

IntroductionCardiovascular magnetic resonance (CMR)-guided cardiac catheterization is becoming more widespread due to the ability to acquire both functional CMR measurements and diagnostic catheterization data without exposing patients to ionizing radiation. However, the real-time imaging sequences used for catheter guidance during these procedures are limited in resolution and the anatomical detail they can provide. In this study, we propose a passive catheter tracking approach which simultaneously improves catheter tracking and visualization of the anatomy.Methods60 patients with congenital heart disease underwent CMR-guided cardiac catheterization on a 1.5T CMR scanner (Ingenia, Philips Healthcare, Best the Netherlands) using the Philips iSuite system. The proposed T1-overlay technique uses a commercially available heavily T1-weighted sequence to image the catheter, and overlays it on a high-resolution 3D dataset within iSuite in real-time. Suppressed tissue in the real-time images enables the use of a thick imaging slab to assist in tracking of the catheter. Improvement in catheter visualization time was compared between T1-overlay and the conventional invasive CMR (iCMR) balanced steady state free precession (bSSFP) sequence. This technique also enabled selective angiography visualization for real-time evaluation of blood flow dynamics (such as pulmonary transit time), similar to direct contrast injection under standard fluoroscopy. Estimates of pulmonary transit time using iCMR were validated using x-ray fluoroscopy in 16 patients.ResultsThe T1-overlay approach significantly increased the time that the catheter tip was kept in view by the technologist compared to the bSSFP sequence conventionally used for iCMR. The resulting images received higher ratings for blood/balloon contrast, anatomy visualization, and overall suitability for iCMR guidance by three cardiologists. iCMR selective angiography using T1-overlay also provided accurate estimates of pulmonary transit time that agreed well with x-ray fluoroscopy.ConclusionWe demonstrate a new passive catheter tracking technique using the iSuite platform that improves visualization of the catheter and cardiac anatomy. These improvements significantly increase the time that the catheter tip is seen throughout the procedure. We also demonstrate the feasibility of iCMR selective angiography for the measurement of pulmonary transit time.

Interarterial Pseudoaneurysm: A Potential Nightmare

Femoral artery pseudoaneurysm (FAP) is one of the most troublesome complications related to femoral artery access site after cardiovascular catheterization procedures and occurs in 0.8%–2.2% of the cases of cardiovascular interventional procedures. Management is by ultrasound-guided compression repair (UGCR). A 75-year-old male presented with anterior wall ST-elevation myocardial infarction and after percutaneous transluminal coronary angioplasty, developed FAP. This pseudoaneurysm had an interarterial communication between superficial femoral artery and deep femoral artery. It is unusual to have communication of pseudoaneurysm with two branches of femoral artery. Diagnosis was made using vascular sonography and Doppler study. Closure of this aneurysm was done by simple pressure with Doppler probe at both the narrow ends of the aneurysm. Arterial color Doppler is the mainstay for diagnosing FAPs. This case describes an interarterial pseudoaneurysm which is a rare entity to witness and the different modalities for its management, the most common one being UGCR.

International trainer perceptions of simulation-based learning: a qualitative study.

Objectives This study examined trainer perceptions of simulation-based learning for Continuing Professional Development in international settings. MethodsA qualitative research methodology was used to gain insight into trainer perceptions. Seventeen international physician trainers involved in simulation training in cardiovascular catheterization and intervention were interviewed. An inductive thematic analysis was performed following steps described by Braun and Clarke; researchers inductively approached, and then carefully dissected the transcripts into individual stories, grounded the problems, and explored themes. ResultsTrainer perceptions are largely aligned with learning theories, even though they were not specifically educated in simulation-based learning and program design principles in advance. Trainers perceive their primary role as facilitators to be most important and consider structuring sessions, facilitating group learning, and stimulating reflection to be crucial themes in simulation-based learning. They believe that building trust is an underlying principle to function in their role and feel responsible for being prepared to improve trainee satisfaction as adult learners. Trainers believe that learning from making mistakes is an important mechanism in simulation-based learning, but they give less attention to giving feedback. ConclusionsTrainers with basic training in facilitation skills in a classroom may unconsciously follow teacher-student instructional models with which they are familiar. This study confirms that trainers in simulation-based learning need pedagogical and facilitating skills to guide trainees and facilitate group processes. Educational training for trainers should include building trust and giving feedback in a more explicit place. In future studies, a mixed-method methodology is suggested to evaluate multi-layered complexities of educational practices.

Cardiovascular Intervention in Neonates Using an Umbilical Vein Approach.

Cardiovascular catheterization has been applied in infant treatment for several decades. To date, considerable research attention has been paid to cardiovascular catheterization in small neonates. However, peripheral vascular routes of catheterization are possible obstacles for interventionists. Umbilical vein catheterization has been reported as a route for neonates, although few attempts have been made to investigate this approach. This study aimed to retrospectively review cardiovascular intervention using the umbilical vein approach as applied to infants admitted to a tertiary center from 2017 to 2020. Details including the perinatal variables, indication diagnoses, and procedure devices were collected. The enrollment included a total of 16 cases representing 17 intervention events, with infants born at a gestation age of 22–39 weeks and body weight ranging from 478 to 3685 g at the time of the procedure. The postnatal age ranged from 1 to 27 days. The catheter sizes ranged from 4 to 11 Fr. Indications included being admitted for patent ductus arteriosus occlusion (n = 15), balloon pulmonary valvuloplasty (n = 3), balloon atrial septostomy (BAS) (n = 3), pulmonary valve (PV) perforation (n = 1), and two interventions for catheter placement for continuous venovenous hemofiltration. The success rate for cardiovascular catheterization was 88.2% (15/17). There were two patients for which cannulation failed due to ductus venosus closure: one intraabdominal hemorrhage complication during continuous venovenous hemofiltration (CVVH), and one cardiac catheterization failure of PV perforation due to failure to insert the guiding catheter into the right ventricular outflow tract. Based on these findings, we conclude that cardiac catheterization and the placement of a large-sized catheter through an umbilical vein in a small infant represents a safe and time-saving method when catheterization is required.

Nontraditional risk factors of coronary artery disease among Palestinians: A case-control study

BackgroundCoronary Artery Disease (CAD) is one of the most common causes of death in Palestine. This study aimed to assess the nontraditional risk factors among CAD patients underwent invasive coronary angiography in Gaza-Palestine. MethodsUnmatched one-to-one case-control study was conducted among 200 participants. Cases were recruited from newly discovered CAD patients after a confirmed diagnosis of CAD by interventional cardiologist post catheterization "coronary angiography" in Al-Shifa Cardiovascular Catheterization Center. Controls were enrolled from individuals with no history of CAD. An interview-based questionnaire was used to assess patient's characteristic data and medical history; anthropometric, and the Ankle Brachial Index(ABI) was measured and calculated. Furthermore, biochemical analysis of high sensitivity C-reactive protein (hs-CRP) level and Random blood glucose level (RBG) and Leukocyte count (WBCs)were investigated. All required ethical approvals were obtained. Data were managed and analyzed by STATA version 14. Correlation analysis by multivariate logistic regression was done. Resultshs-CRP, RBG, and WBCs remained significant predictors for CAD adjusted for age, education level, employment status, and monthly income. As, the odds of CAD increased by 3% for each unit increased in hs-CRP (Odd Ratio (OR)=1.03; 95% confidence interval (CI):1.01, 1.06; P = 0.020); and the odds of CAD was augmented by 30% for each unit increased in WBCs (OR= 1.30; 95% CI: 1.07, 1.67; P = 0.010); While the odds of CAD was 5 times more for each unit increased in RBG (OR=5.04; 95% CI: 1.17, 14.88; P = 0.003). Still, age remained a significant risk factor as the odds of CAD was 19% more for each increased year in age (OR=1.19; 95%CI: 1.13, 1.26; P<0.001). ConclusionNontraditional factors (hs-CRP, RBG, and WBCs) are significant predictors of CAD, and should be considered in adult patients coming with attacks of angina pain.

Cardiorespiratory Parameters in Intermittent Positive Pressure Ventilation Versus Spontaneous Ventilation in Under One-Year-Old Pediatrics: A Randomized Trial

Background: Cardiac catheterization is a useful method for determining the anatomy and pressure in cardiac vessels and chambers. The use of anesthesia methods with minimal hemodynamic and respiratory effects can increase diagnostic accuracy. Objectives: Since there are a few exclusive pediatric angiography centers, scarce studies have been done in this area. Accordingly, this study determined the effects of intermittent positive pressure ventilation (IPPV) versus spontaneous ventilation on cardiorespiratory parameters in less than one-year-old pediatric patients undergoing angiography with general anesthesia. Methods: In this interventional study that was performed as a double-blind, randomized clinical trial, 60 children younger than one year were enrolled. The pulmonary, renal, hepatic, and metabolic background diseases, previous cardiac and thoracic surgery, requiring over two ketamine doses, and receiving sedative or anti-convulsant therapeutics were excluded. The patients were randomly assigned to two groups, including IPPV and spontaneous ventilation. Their vital signs were also recorded before and after anesthesia induction and needling, as well as during measurements of pulmonary parameters and systemic blood pressure. All measurements were done by a single operator using the same device for each variable. Results: It was seen that SPO2, as well as PCO2 after anesthesia had significant alterations among the study variables. Nausea and vomiting, pain, and agitation were not different across the groups (P-value &gt; 0.05). Conclusions: In this study, we found that IPPV and spontaneous ventilation have the same effects on respiration. Both techniques can be used in children with different cardiovascular catheterization conditions to increase accuracy and reduce alterations in cardiopulmonary parameters.

Vasomotor Function of Radial Artery after Conventional Transradial Approach and Dorsal (Snuff Box) Approach

The trans outspread way to deal with cardiovascular catheterization has numerous benefits over the transfemoral approach and is progressively being utilized for both analytic coronary angiography and percutaneous coronary intercession. This investigation is intended to gauge the stream intervened expansion of the outspread supply route preceding and after the transradial approach for coronary angiography utilizing traditional transradial approach and dorsal transradial approach through snuff box. Patient and strategies: This is a planned observational investigation included 100 patients for transradial approach for coronary angiography. Patients were separated into two groups:Group (I): through ordinary transradial approach Group (II): through dorsal snuff box approach. All patients went through spiral conduit B-mode ultrasound imaging, and stream interceded dilatation (FMD) was utilized preceding catheterization and inside 10 days following the catheterization.Diameter of the outspread vein was estimated by high-goal outer vascular ultrasound because of an increment in blood stream (causing shear-stress) Results: A critical distinction between the ordinary and dorsal snuff box course in spiral corridor width after FMD pre and post strategy (estimated inside 10 days follow up of the patient ) with a pre-procedural mean breadth 0.275± 0.619mm (2.92 ± 0.747 versus 2.59 ± 0.491in traditional and dorsal gathering separately, P =0.010). There were ten instances of outspread course impediment at multi week follow up, 2 and 8 patients in traditional (4%) and dorsal routes(16%) individually, P=0.046 in any case, none of them was suggestive. We regularly utilized either IV or intra-blood vessel heparin for prophylaxis of spiral corridor impediment. End: Distal spiral methodology through the anatomical snuff box is arising as a practical and safe option in contrast to traditional one with a few benefits.

BLEEDING COMPLICATIONS AFTER ARTERIAL CANNULATION PERFORMED BY RESIDENTS COMPARED WITH PROPENSITY-MATCHED SENIOR CARDIOLOGISTS UNDERGOING CARDIOVASCULAR CATHETERIZATION

Arterial sheath insertion (cannulation) is the first procedure of cardiovascular catheterization, and sometimes performed by residents. But there is little data regarding bleeding complications after resident’s cannulation compared with senior cardiologist’s cannulation. Consecutive 334

Real-time 3T MRI-guided cardiovascular catheterization in a porcine model using a glass-fiber epoxy-based guidewire.

PurposeReal-time magnetic resonance imaging (MRI) is a promising alternative to X-ray fluoroscopy for guiding cardiovascular catheterization procedures. Major challenges, however, include the lack of guidewires that are compatible with the MRI environment, not susceptible to radiofrequency-induced heating, and reliably visualized. Preclinical evaluation of new guidewire designs has been conducted at 1.5T. Here we further evaluate the safety (device heating), device visualization, and procedural feasibility of 3T MRI-guided cardiovascular catheterization using a novel MRI-visible glass-fiber epoxy-based guidewire in phantoms and porcine models.MethodsTo evaluate device safety, guidewire tip heating (GTH) was measured in phantom experiments with different combinations of catheters and guidewires. In vivo cardiovascular catheterization procedures were performed in both healthy (N = 5) and infarcted (N = 5) porcine models under real-time 3T MRI guidance using a glass-fiber epoxy-based guidewire. The times for each procedural step were recorded separately. Guidewire visualization was assessed by measuring the dimensions of the guidewire-induced signal void and contrast-to-noise ratio (CNR) between the guidewire tip signal void and the blood signal in real-time gradient-echo MRI (specific absorption rate [SAR] = 0.04 W/kg).ResultsIn the phantom experiments, GTH did not exceed 0.35°C when using the real-time gradient-echo sequence (SAR = 0.04 W/kg), demonstrating the safety of the glass-fiber epoxy-based guidewire at 3T. The catheter was successfully placed in the left ventricle (LV) under real-time MRI for all five healthy subjects and three out of five infarcted subjects. Signal void dimensions and CNR values showed consistent visualization of the glass-fiber epoxy-based guidewire in real-time MRI. The average time (minutes:seconds) for the catheterization procedure in all subjects was 4:32, although the procedure time varied depending on the subject’s specific anatomy (standard deviation = 4:41).ConclusionsReal-time 3T MRI-guided cardiovascular catheterization using a new MRI-visible glass-fiber epoxy-based guidewire is feasible in terms of visualization and guidewire navigation, and safe in terms of radiofrequency-induced guidewire tip heating.

Opportunities in Interventional and Diagnostic Imaging by Using High-Performance Low-Field-Strength MRI.

Background Commercial low-field-strength MRI systems are generally not equipped with state-of-the-art MRI hardware, and are not suitable for demanding imaging techniques. An MRI system was developed that combines low field strength (0.55 T) with high-performance imaging technology. Purpose To evaluate applications of a high-performance low-field-strength MRI system, specifically MRI-guided cardiovascular catheterizations with metallic devices, diagnostic imaging in high-susceptibility regions, and efficient image acquisition strategies. Materials and Methods A commercial 1.5-T MRI system was modified to operate at 0.55 T while maintaining high-performance hardware, shielded gradients (45 mT/m; 200 T/m/sec), and advanced imaging methods. MRI was performed between January 2018 and April 2019. T1, T2, and T2* were measured at 0.55 T; relaxivity of exogenous contrast agents was measured; and clinical applications advantageous at low field were evaluated. Results There were 83 0.55-T MRI examinations performed in study participants (45 women; mean age, 34 years ± 13). On average, T1 was 32% shorter, T2 was 26% longer, and T2* was 40% longer at 0.55 T compared with 1.5 T. Nine metallic interventional devices were found to be intrinsically safe at 0.55 T (<1°C heating) and MRI-guided right heart catheterization was performed in seven study participants with commercial metallic guidewires. Compared with 1.5 T, reduced image distortion was shown in lungs, upper airway, cranial sinuses, and intestines because of improved field homogeneity. Oxygen inhalation generated lung signal enhancement of 19% ± 11 (standard deviation) at 0.55 T compared with 7.6% ± 6.3 at 1.5 T (P = .02; five participants) because of the increased T1 relaxivity of oxygen (4.7e-4 mmHg-1sec-1). Efficient spiral image acquisitions were amenable to low field strength and generated increased signal-to-noise ratio compared with Cartesian acquisitions (P < .02). Representative imaging of the brain, spine, abdomen, and heart generated good image quality with this system. Conclusion This initial study suggests that high-performance low-field-strength MRI offers advantages for MRI-guided catheterizations with metal devices, MRI in high-susceptibility regions, and efficient imaging. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Grist in this issue.

Lens changes in cardiovascular catheterization laboratories staff

Objectiveto determine the association between occupational ionizing radiation exposure in the cardiovascular catheterization laboratories staff and development of lens changes. Methodsa cross-sectional study was made. Participants were recruited at the XIII Colombian Conference of Interventional Cardiology and SOLACI conferences in Bogotá - Colombia 2017. Informed consent was obtained from all study participants. Demographics and clinical data were collected. Associated lens changes were determined according to the ionizing radiation exposure status. Resultsa total of 89 subjects (178 eyes) participated in the study. In general, the mean age was 40 years old, ranging from 19 to 78 years old. Distribution according gender was 55.3% male and 44.7% female. 31 subjects (62 eyes) were deemed to have not occupational exposure to radiation and 58 subjects (116 eyes) with a history of occupational radiation exposure. Exposed eyes had twice risk for present subcapsular posterior lens opacity compared to non-exposed eyes. The subjects with older age and physician role were associated to the presence of lens opacity, with a p value 0.001 in both cases. Likewise, exposed subjects with any lens opacity had a high mean occupational lifetime, with a p 0.001. Conclusionsthis study confirms a statistically significant increase in radiation-associated subcapsular lens changes in the eyes of interventional cardiology staff compared to unexposed controls.

Functionalization of endovascular devices with superparamagnetic iron oxide nanoparticles for interventional cardiovascular magnetic resonance imaging.

Presently, cardiovascular interventions such as stent deployment and balloon angioplasty are performed under x-ray guidance. However, x-ray fluoroscopy has poor soft tissue contrast and is limited by imaging in a single plane, resulting in imprecise navigation of endovascular instruments. Moreover, x-ray fluoroscopy exposes patients to ionizing radiation and iodinated contrast agents. Magnetic resonance imaging (MRI) is a safe and enabling modality for cardiovascular interventions. Interventional cardiovascular MR (iCMR) is a promising approach that is in stark contrast with x-ray fluoroscopy, offering high-resolution anatomic and physiologic information and imaging in multiple planes for enhanced navigational accuracy of catheter-based devices, all in an environment free of radiation and its deleterious effects. While iCMR has immense potential, its translation into the clinical arena is hindered by the limited availability of MRI-visible catheters, wire guides, angioplasty balloons, and stents. Herein, we aimed to create application-specific, devices suitable for iCMR, and demonstrate the potential of iCMR by performing cardiovascular catheterization procedures using these devices. Tools, including catheters, wire guides, stents, and angioplasty balloons, for endovascular interventions were functionalized with a polymer coating consisting of poly(lactide-co-glycolide) (PLGA) and superparamagnetic iron oxide (SPIO) nanoparticles, followed by endovascular deployment in the pig. Findings from this study highlight the ability to image and properly navigate SPIO-functionalized devices, enabling interventions such as successful stent deployment under MRI guidance. This study demonstrates proof-of-concept for rapid prototyping of iCMR-specific endovascular interventional devices that can take advantage of the capabilities of iCMR.