Comprehensive Shielding System Enhances Radiation Protection for Structural Heart Procedures.

Background: This study of radiation exposure (RE) to physicians performing structural heart procedures evaluated the efficacy of a novel comprehensive radiation shield compared to those of traditional shielding methods. A novel comprehensive shielding system (Protego, Image Diagnostics Inc) has been documented to provide superior RE protection during coronary procedures compared to that provided by a standard "drop down" shield. The purpose of this study was to assess the efficacy of this shield in transcatheter aortic valve replacement (TAVR) procedures, which are associated with disproportionate RE to operators. Methods: This single-center, 2-group cohort, observational analysis compared RE to the primary physician operator performing TAVR using the Protego shield (n = 25) with that using a standard drop-down shield with personal leaded apparel (n = 25). RE was measured at both thyroid and waist levels with a real-time dosimetry system (RaySafe i3, RaySafe) and was calculated on a mean per case basis. Data were collected on additional procedural parameters, including access site(s) for device implantation, per case fluoroscopy time, air kerma, and patient factors, including body mass index. Between-group comparisons were conducted to evaluate RE by group and measurement sites. Results: The Protego system reduced operator RE by 99% compared to that using standard protection. RE was significantly lower at both the thyroid level (0.08 ± 0.27 vs 79.2 ± 62.4 µSv; P < .001) and the waist level (0.70 ± 1.50 vs 162.0 ± 91.0 µSv, P < .001). "Zero" total RE was documented by RaySafe in 60% (n = 15) of TAVR cases using Protego. In contrast, standard protection did not achieve zero exposure in a single case. Conclusions: The Protego shield system provides superior operator RE protection during TAVR procedures. This shield allows operators to work without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

Comprehensive radiation shield minimizes operator radiation exposure in coronary and structural heart procedures.

OBJECTIVES: This study evaluated the efficacy of a novel comprehensive shield designed to minimize radiation exposure (RE) to Physicians performing coronary and structural heart procedures. BACKGROUND: The Protego™ radiation shielding system (Image Diagnostics Inc., Fitchburg, Ma) is designed to provide comprehensive protection from RE and has been State certified sufficient to allow operators to perform procedures without orthopedically burdensome lead aprons. METHODS: This single center two-group cohort study assessed the efficacy of this shield in a large number of cardiac procedures (coronary and structural), comparing operator RE compared to standard protection methods (personal lead apparel and "drop down" shield). RESULTS: The Protego™ system reduced operator RE by 99 % compared to Standard Protection. RE was significantly lower at both "Head" level by thyroid median dose 0.0 (0.0, 0,0) vs 5.7 (2.9, 8.2) µSv (p < 0.001), as well as waist dose 0.0 (0.0, 0.0) vs 10.0 (5.0, 16.6) µSv (p < 0.001). "Zero" Total RE was documented by Raysafe™ in 64 % (n = 32) of TAVR cases and 73.2 % (n = 183) of the coronary cases utilizing Protego™. In contrast, standard protection did not achieve "Zero" exposure in a single case. These dramatic differences in RE were achieved despite higher fluoroscopy times in the Protego™ arm (11.9 ± 8.6 vs 14.3 ± 12.5 min, p = 0.015). Per case procedural exposure measured by Dose Area Product was higher in the Protego™ group compared to standard protection (115.4 ± 139.2 vs 74.9 ± 69.3, p < 0.001). CONCLUSION: The Protego™ shield provides total body RE protection for operators performing both coronary and structural heart procedures. This shield allows procedural performance without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

Experimental validation of rotating detonation for rocket propulsion.

Space travel requires high-powered, efficient rocket propulsion systems for controllable launch vehicles and safe planetary entry. Interplanetary travel will rely on energy-dense propellants to produce thrust via combustion as the heat generation process to convert chemical to thermal energy. In propulsion devices, combustion can occur through deflagration or detonation, each having vastly different characteristics. Deflagration is subsonic burning at effectively constant pressure and is the main means of thermal energy generation in modern rockets. Alternatively, detonation is a supersonic combustion-driven shock offering several advantages. Detonations entail compact heat release zones at elevated local pressure and temperature. Specifically, rotating detonation rocket engines (RDREs) use detonation as the primary means of energy conversion, producing more useful available work compared to equivalent deflagration-based devices; detonation-based combustion is poised to radically improve rocket performance compared to today's constant pressure engines, producing up to 10[Formula: see text] increased thrust. This new propulsion cycle will also reduce thruster size and/or weight, lower injection pressures, and are less susceptible to engine-damaging acoustic instabilities. Here we present a collective effort to benchmark performance and standardize operability of rotating detonation rocket engines to develop the RDRE technology readiness level towards a flight demonstration. Key detonation physics unique to RDREs, driving consistency and control of chamber dynamics across the engine operating envelope, are identified and addressed to drive down the variability and stochasticity observed in previous studies. This effort demonstrates an RDRE operating consistently across multiple facilities, validating this technology's performance as the foundation of RDRE architecture for future aerospace applications.

Comprehensive Radiation Shield Minimizes Operator Radiation Exposure and Obviates Need for Lead Aprons.

Background: The catheterization laboratory predisposes to occupational health hazards. Chronic radiation exposure (RE) direct injuries include a predilection to cataracts and concerns for cancers. Indirectly adverse effects underly the prevalence of orthopedic maladies in interventionists, linked to the burden of mandatory protective lead aprons. A novel comprehensive shielding system (Protego, Image Diagnostics Inc) has been validated in early studies to provide excellent radiation protection. The system is designed to reduce operator RE sufficient to eliminate the need for personal lead aprons. Recent system refinements offer potentially even greater degrees of protection. This clinical study evaluated the efficacy of this system. Methods: This single-center 2-group cohort study compared physician operator RE utilizing the latest iteration of the Protego shield (n = 25 cases) or standard protection (personal leaded apparel and drop-down shield, n = 25 cases) during routine cardiac catheterization procedures. RE at both thyroid and waist levels were measured with a real-time dosimetry system (Raysafe) and calculated on a mean per case basis at both thyroid and waist levels. Additional parameters collected included procedure type, access site, per case fluoroscopy time, and patient factors including body mass index. Between-group comparisons were conducted to evaluate RE by group and measurement sites. Results: Protection with Protego was superior to standard methods. Protego showed markedly lower RE at both the thyroid level (0.36 ± 0.86 vs 58.5 ± 50.2 µSv; P < .001) and the waist level (0.84 ± 2.99 vs 121.4 ± 171.2 µSv; P < .001. "Zero" total RE was documented in 68% (n = 17) of Protego cases; in contrast, standard protection did not achieve "zero" exposure in a single case. Conclusions: The Protego shield system provides excellent RE protection to the physician operator, achieving "zero" RE in two-thirds of cases. RE was superior to standard protection methods. The magnitude of protection achieves state regulatory standards sufficient to allow operators to perform procedures without orthopedically burdensome lead aprons. This shield system has the potential to reduce occupational health hazards.

Novel Transcatheter Mitral Valve Prosthesis for Patients With Severe Mitral Annular Calcification.

BACKGROUND: Treatment of mitral regurgitation (MR) in the setting of severe mitral annular calcification (MAC) is challenging due to the high risk for fatal atrioventricular groove disruption and significant paravalvular leak. OBJECTIVES: The objective of this study was to evaluate the potential for transcatheter mitral valve replacement in patients with severe MAC using an anatomically designed mitral prosthesis. METHODS: Nine patients (77 ± 6 years of age; 5 men) were treated with the valve, using transapical delivery performed under general anesthesia and with guidance from transesophageal echocardiography and fluoroscopy. RESULTS: Device implantation was successful with relief of MR in all 9 patients. There were no procedural deaths. In 1 patient, left ventricular outflow tract obstruction occurred due to malrotation of the prosthesis, and successful alcohol septal ablation was performed. During a median follow-up of 12 months (range 1 to 28 months), there was 1 cardiac death, 1 noncardiac death, no other mortality, and no prosthetic dysfunction, and MR remained absent in all treated patients. Rehospitalization for heart failure occurred in 2 patients who did not die subsequently. Clinical improvement with mild or no symptoms occurred in all patients alive at the end of follow-up. CONCLUSIONS: Transcatheter mitral valve replacement in severe mitral annular calcification with a dedicated prosthesis is feasible and can result in MR relief with symptom improvement. Further evaluation of this approach for these high-risk patients is warranted.

Urgent mechanical circulatory support and transcatheter mitral valve repair for refractory hemodynamic compromise.

Patients presenting with hemodynamic instability attributable to left ventricular systolic dysfunction and concomitant severe mitral regurgitation (MR) are increasingly recognized and pose complex management challenges. Surgical therapy is typically precluded owing to prohibitive mortality. The role of percutaneous mechanical circulatory support in such cases is well established; however, such interventions may be neither sufficient to achieve optimal stability nor prove definitive. The advent of novel catheter-based mitral repair modalities now offers primary decisive therapeutic intervention. Three cases of cardiogenic shock with severe MR illustrate the salutary hemodynamic and clinical responses to percutaneous mechanical support and valve repair by mitral clip.

First US experience following FDA approval of the ABBOTT vascular bioresorbable vascular scaffold for the treatment of coronary artery disease.

Drug eluting stents are considered the "gold standard" for the percutaneous treatment of coronary artery disease. Recent publications have suggested that a reasonable alternative, in well selected cases, may be the ABSORBTM bioresorbable vascular scaffold (BVS) stent. © 2016 Wiley Periodicals, Inc.

Interventional Management of Unprotected Left Main Coronary Artery Disease: Patient Selection and Technique Optimization.

For many years, coronary artery bypass graft surgery has been the gold standard for revascularization of patients with left main disease; however, increasing evidence suggests that percutaneous coronary intervention with drug-eluting stents may be an acceptable alternative or even preferred in select cases. This review will present clinical evidence examining the outcomes of drug-eluting stents compared to coronary artery bypass graft surgery for unprotected left main coronary artery disease and discuss the anatomic factors, patient variables, and clinical strategies that may dictate choice of revascularization modality for patients with left main disease. If percutaneous coronary intervention is selected to treat unprotected left main disease, meticulous technique is essential to optimize outcomes, including use of procedural physiology and imaging guidance, optimal stent and adjunct pharmacology use, and expert management of the distal bifurcation. Finally, issues of equipoise and uncertainty are identified, representing areas for future investigation.

Incidence of subclinical atherosclerosis as a marker of cardiovascular risk in retired professional football players.

The purpose of this study was to evaluate subclinical atherosclerosis in retired professional football players. Two hundred one healthy former professional football players (mean age 50.8 years; mean body mass index 31.5 kg/m(2)) were screened for the prevalence of cardiovascular risk factors, metabolic syndrome, and subclinical atherosclerosis by carotid artery ultrasound and compared with a cohort of men of similar body mass index referred for the assessment of subclinical atherosclerosis by carotid ultrasound. The prevalence of carotid artery plaque in the players was not significantly different from that of the body mass index-matched patients (33.3% vs 29.3%, p = 0.45). For the 2 groups, the prevalence of carotid artery plaque was >3 times higher than that reported in general population studies of patients with the same age range, gender, and exclusions. Metabolic syndrome prevalence was higher in linemen than in nonlinemen (45.8% vs 22.5%, p = 0.001), but there was no statistical difference in plaque presence between linemen and nonlinemen (27.1% vs 35.9%, p = 0.23). In conclusion, despite their elite athletic histories, former professional football players have a similar prevalence of advanced subclinical atherosclerosis as a clinically referred population of overweight and obese men.

Cerebral ischemic events associated with 'bubble study' for identification of right to left shunts.

BACKGROUND AND PURPOSE: Detection of an intracardiac shunt is frequently sought during the evaluation of patients with cryptogenic ischemic stroke and agitated saline intravenous injection, or "bubble study" (BS), is performed in most cases. We present the first attempt to identify the clinical features in patients who had cerebral ischemic events with BS. METHODS: Using a list serve established by the American Academy of Neurology, a member posted a question regarding the safety of BS in patients with patent foramen ovale. A standardized questionnaire was used to gather data about patients with cerebral ischemic events, details of each case were reviewed, and the findings pooled. RESULTS: Five patients with ischemic complications of BS (all female, aged 42 to 90 years) were identified from 4 institutions, 3 ischemic strokes and 2 transient ischemic attacks. Events occurred either during or within 5 minutes of BS. Early brain MRIs confirmed acute infarction in 3, including one who had transient symptoms. MRI infarct volumes were small, and deficits were mild in those who developed stroke. Diagnostic evaluation revealed a patent foramen ovale alone in one case, a pulmonary arteriovenous malformation in one case, and a patent foramen ovale and/or pulmonary shunt in 3 cases. CONCLUSIONS: Ischemic cerebrovascular complications can occur in patients who undergo BS and are associated with the presence of cardiac or pulmonary shunts. The true incidence and degree of disability remains unknown, and further study is indicated to assess the impact of technical differences in BS methodology. Novel methods to promote physician communication such as the use of electronic list serves may reduce barriers to reporting of drug, technique, or device complications and should be explored to identify rare complications that otherwise will likely go unappreciated.