Physician Radiation Exposure During Endomyocardial Biopsy and Right Heart Catheterization.

BACKGROUND: Cardiologists performing coronary angiography (CA) and percutaneous coronary intervention (PCI) are at risk of health problems related to chronic occupational radiation exposure. Unlike during CA and PCI, physician radiation exposure during right heart catheterization (RHC) and endomyocardial biopsy (EMB) has not been adequately studied. The objective of this study was to assess physicians' radiation doses during RHC with and without EMB and compare them to those of CA and PCI. METHODS: Procedural head-level physician radiation doses were collected by real-time dosimeters. Radiation-dose metrics (fluoroscopy time, air kerma [AK] and dose area product [DAP]), and physician-level radiation doses were compared among RHC, RHC with EMB, CA, and PCI. RESULTS: Included in the study were 351 cardiac catheterization procedures. Of these, 36 (10.3%) were RHC, 42 (12%) RHC with EMB, 156 (44.4%) CA, and 117 (33.3%) PCI. RHC with EMB and CA had similar fluoroscopy time. AK and DAP were progressively higher for RHC, RHC with EMB, CA, and PCI. Head-level physician radiation doses were similar for RHC with EMB vs CA (P = 0.07). When physicians' radiation doses were normalized to DAP, RHC and RHC with EMB had the highest doses. CONCLUSION: Physicians' head-level radiation doses during RHC with EMB were similar to those of CA. After normalizing to DAP, RHC and RHC with EMB were associated with significantly higher physician radiation doses than CA or PCI. These observations suggest that additional protective measures should be undertaken to decrease physicians' radiation exposure during RHC and, in particular, RHC with EMB.

Robotically performed diagnostic coronary angiography.

OBJECTIVE: This study was performed to investigate the efficacy and safety of robotic diagnostic coronary angiography. BACKGROUND: Robotic percutaneous coronary intervention is associated with marked reductions in physician radiation exposure. Development of robotic diagnostic coronary angiography might similarly impact occupational safety. METHODS: Stable patients referred for coronary angiography were prospectively enrolled. After obtaining vascular access, diagnostic catheters were manually advanced over a wire to the ascending aorta. All subsequent catheter movements were performed robotically. The primary endpoint was procedural success, defined as robotic completion of coronary angiography without conversion to a manual procedure and the absence of procedural major adverse cardiovascular events (MACE-cardiac death, cardiac arrest, or stroke) and major angiographic complications (coronary/aortic dissection or embolization). The primary hypothesis was that the observed rate of the primary endpoint, evaluated at the completion of coronary angiography, would meet a pre-specified performance goal of 74.5%. RESULTS: Among 46 consecutive patients (age 67 ± 12 years; 69.6% male), diagnostic coronary angiography was completed robotically in all cases without the need for manual conversion and without any MACE or major angiographic complications. Thus, procedural success was 100%, which was significantly higher than the pre-specified performance goal (p < 0.001). Robotic coronary angiography was completed using 2 [2, 3] catheters per case with a median procedural time of 15 [11, 20] minutes. CONCLUSIONS: Robotic diagnostic coronary angiography was performed with 100% procedural success and no observed complications. These results support the performance of future studies to further explore robotic coronary angiography.

Suspended lead suit and physician radiation doses during coronary angiography.

OBJECTIVE: This study was performed to evaluate physician radiation doses with the use of a suspended lead suit. BACKGROUND: Interventional cardiologists face substantial occupational risks from chronic radiation exposure and wearing heavy lead aprons. METHODS: Head-level physician radiation doses, collected using real-time dosimeters during consecutive coronary angiography procedures, were compared with the use of a suspended lead suit versus conventional lead aprons. Multiple linear regression analyses were completed using physician radiation doses as the response and testing patient variables (body mass index, age, sex), procedural variables (right heart catheterization, fractional flow reserve, percutaneous coronary intervention, radial access), and shielding variables (radiation-absorbing pad, accessory lead shield, suspended lead suit) as the predictors. RESULTS: Among 1054 coronary angiography procedures, 691 (65.6%) were performed with a suspended lead suit and 363 (34.4%) with lead aprons. There was no significant difference in dose area product between groups (61.7 [41.0, 94.9] mGy·cm2 vs. 64.6 [42.9, 96.9] mGy·cm2 , p = 0.20). Median head-level physician radiation doses were 10.2 [3.2, 35.5] µSv with lead aprons and 0.2 [0.1, 0.9] µSv with a suspended lead suit (p < 0.001), representing a 98.0% reduced dose with suspended lead. In the fully adjusted regression model, the use of a suspended lead suit was independently associated with a 93.8% reduction (95% confidence interval: -95.0, -92.3; p < 0.001) in physician radiation dose. CONCLUSION: Compared to conventional lead aprons, the use of a suspended lead suit during coronary angiography was associated with marked reductions in head-level physician radiation doses.

Target Lesion Lipid Content Detected by Near-Infrared Spectroscopy After Stenting and the Risk of Subsequent Target Lesion Failure.

[Figure: see text].

Robotic telestenting performance in transcontinental and regional pre-clinical models.

OBJECTIVES: This study was conducted to evaluate the association of geographic distance with robotic telestenting performance by comparing performance measures in transcontinental and regional pre-clinical models of telestenting. BACKGROUND: Robotic telestenting, in which percutaneous coronary intervention (PCI) is performed on a remotely located patient, might improve PCI access, but has not been attempted over vast distances likely required to reach many underserved regions. METHODS: Telestenting performance was compared in regional (Boston to New York [206 miles]) and transcontinental (Boston to San Francisco [3,085 miles]) ex vivo models of telestenting, wherein a physician in Boston attempted robotic PCI on endovascular simulators in New York and San Francisco, respectively. PCI was attempted over both wired and fifth generation (5G)-wireless networks. Outcome measures included procedural success, procedural time, and perceived latency. RESULTS: Procedural success was achieved in 20 consecutive target lesions in the regional model and in 16 consecutive target lesions in the transcontinental model. The transcontinental model had a greater latency than the regional model over both wired (121.5 ± 2.4 ms vs. 67.8 ± 0.9 ms; p < .001) and 5G-wireless networks (162.5 ± 1.1 ms vs. 86.6 ± 0.6 ms; p < .001), but perceived latencies were graded "imperceptible" in all cases in both models. Transcontinental and regional models did not have significantly different procedural times over wired (4.1 ± 1.9 min vs. 9.0 ± 7.1 min; p = .051) or 5G-wireless (3.0 ± 0.6 vs. 6.3 ± 1.2; p = .36) networks. CONCLUSIONS: Transcontinental robotic manipulation of coronary devices is now possible and was not associated with adverse performance compared to robotic telestenting conducted regionally.

Network latency and long-distance robotic telestenting: Exploring the potential impact of network delays on telestenting performance.

OBJECTIVE: This study evaluated the impact of network latency on telestenting performance. BACKGROUND: The feasibility of long-distance robotic telestenting was recently demonstrated, yet the impact of network performance on telestenting remains unknown. METHODS: Ex vivo and in vivo telestenting models were constructed by connecting a robotic drive over a wired network to a robotic control system up to 103 miles away. During consecutive attempts to robotically wire a coronary artery, investigators randomly added signal latencies from 0 to 1,000 ms. Outcomes included wiring success, wiring time (time to advance wire to preselected target landmark), and perceived latency score (5 = imperceptible; 4 = noticeable but minor; 3 = noticeable; 2 = noticeable and major; 1 = unacceptable). RESULTS: Wiring success was achieved in 95 of 95 attempts in the ex vivo model and in 57 of 57 attempts in vivo. No significant difference in wiring time was observed across added latencies from 0 to 1,000 ms in the ex vivo (p = .64) or in vivo (p = .40) models. Compared to an added latency of 0 ms, perceived latency scores were not significantly different for added latencies of 150 and 250 ms (p = NS for both), but were significantly lower for latencies ≥400 ms (p < .001). CONCLUSIONS: Added latencies up to 250 ms were not associated with perceived latency, but latencies ≥400 ms were perceptible. Based on these findings, future telestenting studies should utilize networks with latencies ≤250 ms if perceived latency is to be avoided.

Confirmation of the Intracoronary Near-Infrared Spectroscopy Threshold of Lipid-Rich Plaques That Underlie ST-Segment-Elevation Myocardial Infarction.

OBJECTIVE: In a previous exploratory analysis, intracoronary near-infrared spectroscopy (NIRS) found the majority of culprit lesions in ST-segment-elevation myocardial infarction (STEMI) to contain a maximum lipid core burden index in 4 mm (maxLCBI4mm) of >400. This initial study was limited by a small sample size, enrollment at a single center, and post hoc selection of the maxLCBI4mm ≥400 threshold. This study was designed a priori to substantiate the ability of NIRS to discriminate STEMI culprit from nonculprit segments and to confirm the performance of the maxLCBI4mm ≥400 threshold. APPROACH AND RESULTS: At 2 centers in the United States and Sweden, 75 STEMI patients underwent intracoronary NIRS imaging after establishing thrombolysis in myocardial infarction 3 flow, but before stenting. Blinded core laboratory analysis defined the culprit segment as the 10-mm segment distal to the proximal angiographic culprit margin. The remaining vessel was divided into contiguous 10-mm nonculprit segments. The maxLCBI4mm of culprit segments (median [interquartile range]: 543 [273-756]) was 4.4-fold greater than nonculprit segments (median [interquartile range]: 123 [0-307]; P<0.001). Receiver-operating characteristic analysis demonstrated that maxLCBI4mm differentiated culprit from nonculprit segments with high accuracy (c-statistic=0.83; P<0.001). A threshold maxLCBI4mm ≥400 identified STEMI culprit segments with a sensitivity of 64% and specificity of 85%. CONCLUSIONS: This study substantiates the ability of NIRS to accurately differentiate STEMI culprit from nonculprit segments and confirms that a threshold maxLCBI4mm ≥400 is detected by NIRS in the majority of STEMI culprits.

Detection by near-infrared spectroscopy of large lipid cores at culprit sites in patients with non-ST-segment elevation myocardial infarction and unstable angina.

OBJECTIVE: This study was performed to assess the lipid burden of culprit lesions in non-ST-segment elevation myocardial infarction (non-STEMI) and unstable angina (UA). BACKGROUND: A recent intracoronary near-infrared spectroscopy (NIRS) study showed 85% of STEMI culprit lesions have a maximum lipid core burden index in 4-mm (maxLCBI(4mm)) ≥ 400. Whether culprit lesions in non-STEMI and UA are characterized by a similarly large lipid burden is unknown. METHODS: We studied 81 non-STEMI and UA patients undergoing culprit vessel NIRS imaging before stenting. Culprit segments were compared to all nonoverlapping 10-mm nonculprit segments for maxLCBI(4mm). Culprit segments in non-STEMI and UA were compared for the frequency of maxLCBI(4mm) ≥ 400. RESULTS: Among 81 patients (53.1% non-STEMI, 46.9% UA), non-STEMI culprit segments had a 3.4-fold greater maxLCBI(4mm) than nonculprits (448 ± 229 vs 132 ± 154, P < 0.001) and UA culprit segments had a 2.6-fold higher maxLCBI(4mm) than nonculprits (381 ± 239 vs 146 ± 175, P < 0.001). NIRS detected a maxLCBI(4mm) ≥ 400 in 63.6% of culprit segments in NSTEMI and in 38.5% of culprit segments in UA (P = 0.02). Against a background of nonculprit segments, maxLCBI(4mm) ≥ 400 had a sensitivity of 63.6% and specificity of 94.0% for culprit segments in NSTEMI and a sensitivity of 38.5% and specificity of 89.8% for culprit segments in UA. CONCLUSIONS: Large lipid cores similar to those recently detected by NIRS at STEMI culprit sites were frequently observed at culprit sites in patients with non-STEMI and UA. These findings support ongoing prospective trials designed to determine if NIRS can provide site-specific prediction of future acute coronary events.

Cardiac perforation and lead dislodgement after implantation of a MR-conditional pacing lead: a single-center experience.

OBJECTIVE: The purpose of our study was to determine if the rate of lead-related complications was increased with the Medtronic CapSureFix MRI™ SureScan™ 5086 MRI pacing lead (5086; Medtronic Inc., Minneapolis, MN, USA) compared to the previous generation of Medtronic CapSureFix Novus™ 5076 pacing lead (5076). BACKGROUND: The 5086 lead is a newly introduced active-fixation pacemaker lead designed to be used conditionally in a magnetic resonance (MR) scanner. This lead has specific design changes compared to the previous generation of 5076 pacing leads. METHODS: This study was a retrospective case control study of 65 consecutive patients implanted with two 5086 leads compared to 92 consecutive control patients implanted with two 5076 leads over a 14-month period at a high-volume tertiary care hospital. RESULTS: Pericarditis, pericardial effusion, cardiac tamponade, or death within 30 days of implant were seen in eight patients from the 5086 cohort and two from the 5076 cohort (odds ratio 6.3, 95% confidence interval 1.3-30.8, P = 0.02). Lead dislodgement occurred in four of the 5086 patients and in none of the 5076 patients (P < 0.03). CONCLUSIONS: In a high-volume center, the incidence of pericarditis, cardiac perforation, tamponade, death, and lead dislodgement was significantly higher with the MR-conditional Medtronic 5086 lead when compared to the previous generation Medtronic 5076 lead.

Pandemic-Associated Delays in Myocardial Infarction Presentation in Predominantly Rural Counties With Low COVID-19 Prevalence.

Fewer ST-elevation myocardial infarctions (STEMIs) presentations and increased delays in care occurred during the COVID-19 pandemic in urban areas. Whether these associations occurred in a more rural population has not been previously reported. Our objective was to evaluate the impact of COVID-19 on time-to-presentation for STEMI in rural locations. Patients presenting to a large STEMI network spanning 27 facilities and 13 predominantly rural counties between January 1, 2016 and April 30, 2020 were included. Presentation delays, defined as time from symptom onset to arrival at the first medical facility, classified as ≥12 and ≥24 hours from symptom onset were compared among patients in the pre-COVID-19 and the early COVID-19 eras. To account for patient-level differences, 2:1 propensity score matching was performed using binary logistic regression. Among 1,286 patients with STEMI, 1,245 patients presented in the pre-COVID-19 era and 41 presented during the early COVID-19 era. Presentation delays ≥12 hours (19.5% vs 4.0%) and ≥24 hours (14.6% and 0.2%) were more common in COVID-19 than pre-COVID-19 cohorts (p <0.001 for both), despite a low COVID-19 prevalence. Similar results were seen in propensity-matched comparisons (≥12 hours: 19.5% vs 2.4%, p = 0.002; ≥24 hours 14.6% vs 0.0%, p = 0.001). In a predominantly rural STEMI population, delays in seeking medical care after symptom onset were markedly more frequent during the COVID-19 era, despite low COVID-19 prevalence. Considering delays in reperfusion have multiple adverse downstream consequences, these findings may have important implications in rural communities during future pandemic resurgences.

Comparison of Radiation Exposure Among Interventional Echocardiographers, Interventional Cardiologists, and Sonographers During Percutaneous Structural Heart Interventions.

Importance: Transesophageal echocardiography during percutaneous left atrial appendage closure (LAAO) and transcatheter edge-to-edge mitral valve repair (TEER) require an interventional echocardiographer to stand near the radiation source and patient, the primary source of scatter radiation. Despite previous work demonstrating high radiation exposure for interventional cardiologists performing percutaneous coronary and structural heart interventions, similar data for interventional echocardiographers are lacking. Objective: To assess whether interventional echocardiographers are exposed to greater radiation doses than interventional cardiologists and sonographers during structural heart procedures. Design, Setting, and Participants: In this single-center cross-sectional study, radiation doses were collected from interventional echocardiographers, interventional cardiologists, and sonographers at a quaternary care center during 30 sequential LAAO and 30 sequential TEER procedures from July 1, 2016, to January 31, 2018. Participants and study personnel were blinded to radiation doses through data analysis (January 1, 2020, to October 12, 2021). Exposures: Occupation defined as interventional echocardiographers, interventional cardiologists, and sonographers. Main Outcomes and Measures: Measured personal dose equivalents per case were recorded using real-time radiation dosimeters. Results: A total of 60 (30 TEER and 30 LAAO) procedures were performed in 60 patients (mean [SD] age, 79 [8] years; 32 [53.3%] male) with a high cardiovascular risk factor burden. The median radiation dose per case was higher for interventional echocardiographers (10.6 µSv; IQR, 4.2-22.4 µSv) than for interventional cardiologists (2.1 µSv; IQR, 0.2-8.3 µSv; P < .001). During TEER, interventional echocardiographers received a median radiation dose of 10.5 µSv (IQR, 3.1-20.5 µSv), which was higher than the median radiation dose received by interventional cardiologists (0.9 µSv; IQR, 0.1-12.2 µSv; P < .001). During LAAO procedures, the median radiation dose was 10.6 µSv (IQR, 5.8-24.1 µSv) among interventional echocardiographers and 3.5 (IQR, 1.3-6.3 µSv) among interventional cardiologists (P < .001). Compared with interventional echocardiographers, sonographers exhibited low median radiation doses during both LAAO (0.2 µSv; IQR, 0.0-1.6 µSv; P < .001) and TEER (0.0 µSv; IQR, 0.0-0.1 µSv; P < .001). Conclusions and Relevance: In this cross-sectional study, interventional echocardiographers were exposed to higher radiation doses than interventional cardiologists during LAAO and TEER procedures, whereas sonographers demonstrated comparatively lower radiation doses. Higher radiation doses indicate a previously underappreciated occupational risk faced by interventional echocardiographers, which has implications for the rapidly expanding structural heart team.

Remote robotic endovascular thrombectomy for acute ischaemic stroke.

BACKGROUND: In acute ischaemic stroke, endovascular thrombectomy (ET) significantly reduces disability compared with thrombolytic therapy, but access to ET is currently limited. Leveraging telerobotic technology to disseminate neurosurgical expertise could increase access to ET. This proof-of-concept evaluation was performed to determine whether remote robotic ET (RRET), wherein an offsite neurosurgeon and an onsite interventional cardiologist collaboratively use telerobotics to perform ET, is technically feasible. METHODS: An ex vivo model of RRET was constructed by establishing a network connection between a robotic drive in a simulation laboratory and a robotic control unit 5 miles away. Using onsite assistance from an interventional cardiologist in the simulation laboratory, an offsite neurosurgeon used the robotic controls to attempt RRET on a fluid-filled silicone model of human vasculature containing simulated thrombus material in the left middle cerebral artery (MCA). RESULTS: From the offsite location 5 miles away, the neurosurgeon used the robotic system to successfully navigate a guidewire from the carotid artery to simulated thrombus in the MCA. Under the direction of the neurosurgeon, the onsite interventional cardiologist then successfully manually advanced an aspiration catheter over the guidewire to the thrombus, removed the guidewire and performed aspiration. CONCLUSIONS: In this proof-of-concept evaluation, the technical feasibility of RRET was demonstrated in an ex vivo model and was collaboratively performed by an offsite neurosurgeon and an onsite interventional cardiologist. This report supports the design of future studies to determine if RRET could be used to increase access to ET for patients with acute ischaemic stroke.

Patient Body Mass Index and Occupational Radiation Doses to Circulating Nurses During Coronary Angiography.

BACKGROUND: Patient BMI is associated with radiation doses received by interventional cardiologists, yet the association between patient BMI and nurse radiation doses is unknown. This study evaluated the association between patient body mass index (BMI) and nurse radiation doses during coronary angiography. METHODS: Nurse radiation doses were collected by real-time dosimeters during consecutive coronary angiography procedures and are reported as the personal dose equivalent (Hp10). Patient radiation doses were estimated using dose area product (DAP). Patient BMI was categorized in kg/m2 as <25.0, 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40. Multiple regression analysis determined procedural factors independently association with nurse radiation doses. RESULTS: In 643 consecutive coronary angiography procedures, patient radiation doses increased significantly across increasing patient BMI categories (p < 0.001). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 2.3-fold increase in DAP (p < 0.001). Significant differences were also observed in nurse radiation doses across patient BMI categories (p = 0.036). Compared to a patient BMI <25, a patient BMI ≥40 was associated with a 4.0-fold increase in nurse radiation dose (BMI < 25: 0.3 [0.1, 1.3] µSv; BMI ≥ 40: 1.2 [0.2, 2.9] µSv; p = 0.003). By multiple regression analysis, each 1-unit kg/m2 increase in patient BMI was associated with a 3.3% increase in nurse radiation dose (p = 0.002). CONCLUSIONS: Patient BMI was significantly associated with nurse radiation doses during coronary angiography. These observations may have important implications on nurse radiation safety, especially in the setting of the ongoing obesity epidemic.

Spatial relationships among hemodynamic, anatomic, and biochemical plaque characteristics in patients with coronary artery disease.

BACKGROUND AND AIMS: We aimed to characterize the spatial proximity of plaque destabilizing features local endothelial shear stress (ESS), minimal luminal area (MLA), plaque burden (PB), and near-infrared spectroscopy (NIRS) lipid signal in high- vs. low-risk plaques. METHODS: Coronary arteries imaged with angiography and NIRS-intravascular ultrasound (IVUS) underwent 3D reconstruction and computational fluid dynamics calculations of local ESS. ESS, PB, MLA, and lipid core burden index (LCBI), for each 3-mm arterial segment were obtained in arteries with large lipid-rich plaque (LRP) vs. arteries with smaller LRP. The locations of the MLA, minimum ESS (minESS), maximum ESS (maxESS), maximum PB (maxPB), and maximum LCBI in a 4-mm segment (maxLCBI4mm) were determined along the length of each plaque. RESULTS: The spatial distributions of minESS, maxESS, maxPB, and maxLCBI4mm, in reference to the MLA, were significantly heterogeneous within and between each variable. The location of maxLCBI4mm was spatially discordant from sites of the MLA (p<0.0001), minESS (p = 0.003), and maxESS (p = 0.003) in arteries with large LRP (maxLCBI4mm ≥ 400) and non-large LRP. Large LRP arteries had higher maxESS (9.31 ± 4.78 vs. 6.32 ± 5.54 Pa; p = 0.023), lower minESS (0.41 ± 0.16 vs. 0.61 ± 0.26 Pa; p = 0.007), smaller MLA (3.54 ± 1.22 vs. 5.14 ± 2.65 mm2; p = 0.002), and larger maxPB (70.64 ± 9.95% vs. 56.70 ± 13.34%, p<0.001) compared with non-large LRP arteries. CONCLUSIONS: There is significant spatial heterogeneity of destabilizing plaque features along the course of both large and non-large LRPs. Large LRPs exhibit significantly more abnormal destabilizing plaque features than non-large LRPs. Prospective, longitudinal studies are required to determine which patterns of heterogeneous destabilizing features act synergistically to cause plaque destabilization.

Patient Body Mass Index and Physician Radiation Dose During Coronary Angiography.

BACKGROUND: Consistent with the increasing prevalence of obesity in the general population, obesity has become more prevalent among patients undergoing cardiac catheterization. This study evaluated the association between patient body mass index (BMI) and physician radiation dose during coronary angiography. METHODS AND RESULTS: Real-time radiation exposure data were collected during consecutive coronary angiography procedures. Patient radiation dose was estimated using dose area product. Physician radiation dose in each case was recorded by a dosimeter worn by the physician and is reported as the personal dose equivalent (Hp10). Patient BMI was categorized as <25.0, 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and ≥40. Among 1119 coronary angiography procedures, significant increases in dose area product and physician radiation dose were observed across increasing patient BMI categories ( P<0.001). Compared with a BMI <25, a patient BMI ≥40 was associated with a 2.1-fold increase in patient radiation dose (dose area product, 91.8 [59.6-149.2] versus 44.5 [25.7-70.3] Gy×cm2; P<0.001) and a 7.0-fold increase in physician radiation dose (1.4 [0.2-7.1] versus 0.2 [0.0-2.9] µSv; P<0.001). By multiple regression analysis, patient BMI remained independently associated with physician radiation dose (dose increase, 5.2% per unit increase in BMI; 95% CI, 3.0%-7.5%; P<0.0001). CONCLUSIONS: Among coronary angiography procedures, increasing patient BMI was associated with a significant increase in physician radiation dose. Additional studies are needed to determine whether patient obesity might have adverse effects on physicians, in the form of increased radiation doses during coronary angiography.

Radiation Exposure Among Scrub Technologists and Nurse Circulators During Cardiac Catheterization: The Impact of Accessory Lead Shields.

OBJECTIVES: This study was performed to determine if the use of an accessory lead shield is associated with a reduction in radiation exposure among staff members during cardiac catheterization. BACKGROUND: Accessory lead shields that protect physicians from scatter radiation are standard in many catheterization laboratories, yet similar shielding for staff members is not commonplace. METHODS: Real-time radiation exposure data were prospectively collected among nurses and technologists during 764 consecutive catheterizations. The study had 2 phases: in phase I (n = 401), standard radiation protection measures were used, and in phase II (n = 363), standard radiation protection measures were combined with an accessory lead shield placed between the staff member and patient. Radiation exposure was reported as the effective dose normalized to dose-area product (EDAP). RESULTS: Use of an accessory lead shield in phase II was associated with a 62.5% lower EDAP per case among technologists (phase I: 2.4 [4.3] µSv/[mGy × cm2] × 10-5; phase II: 0.9 [2.8] µSv/[mGy × cm2] × 10-5; p < 0.001) and a 63.6% lower EDAP per case among nurses (phase I: 1.1 [3.1] µSv/[mGy × cm2] × 10-5; phase II: 0.4 [1.8] µSv/[mGy × cm2] × 10-5; p < 0.001). By multivariate analysis, accessory shielding remained independently associated with a lower EDAP among both technologists (34.2% reduction; 95% confidence interval: 20.1% to 45.8%; p < 0.001) and nurses (36.4% reduction; 95% confidence interval: 19.7% to 49.6%; p < 0.001). CONCLUSIONS: The relatively simple approach of using accessory lead shields to protect staff members during cardiac catheterization was associated with a nearly two-thirds reduction in radiation exposure among nurses and technologists.

Impact of patient obesity on radiation doses received by scrub technologists during coronary angiography.

BACKGROUND: The impact of patient obesity on scrub technologist radiation dose during coronary angiography has not been adequately studied. METHODS: Real-time radiation exposure data were prospectively collected during consecutive coronary angiography cases. Patient radiation dose was estimated by dose area product (DAP). Technologist radiation dose was recorded by a dosimeter as the personal dose equivalent (Hp (10)). Patients were categorized according to their body mass index (BMI): <25.0, lean; 25.0-29.9, overweight; ≥30.0, obese. The study had two phases: in Phase I (N = 351) standard radiation protection measures were used; and in Phase II (N = 268) standard radiation protection measures were combined with an accessory lead shield placed between the technologist and patient. RESULTS: In 619 consecutive coronary angiography procedures, significant increases in patient and technologist radiation doses were observed across increasing patient BMI categories (p < 0.001 for both). Compared to lean patients, patient obesity was associated with a 1.7-fold increase in DAP (73.0 [52.7, 127.5] mGy × cm2 vs 43.6 [25.1, 65.7] mGy × cm2, p < 0.001) and a 1.8-fold increase in technologist radiation dose (1.1 [0.3, 2.7] µSv vs 0.6 [0.1, 1.6] µSv, p < 0.001). Compared to Phase I, use of an accessory lead shield in Phase II was associated with a 62.5% reduction in technologist radiation dose when used in obese patients (p < 0.001). CONCLUSIONS: During coronary angiography procedures, patient obesity was associated with a significant increase in scrub technologist radiation dose. This increase in technologist radiation dose in obese patients may be mitigated by use of an accessory lead shield.

Impact of robotics and a suspended lead suit on physician radiation exposure during percutaneous coronary intervention.

BACKGROUND: Reports of left-sided brain malignancies among interventional cardiologists have heightened concerns regarding physician radiation exposure. This study evaluated the impact of a suspended lead suit and robotic system on physician radiation exposure during percutaneous coronary intervention (PCI). METHODS: Real-time radiation exposure data were prospectively collected from dosimeters worn by operating physicians at the head- and chest-level during consecutive PCI cases. Exposures were compared in three study groups: 1) manual PCI performed with traditional lead apparel; 2) manual PCI performed using suspended lead; and 3) robotic PCI performed in combination with suspended lead. RESULTS: Among 336 cases (86.6% manual, 13.4% robotic) performed over 30weeks, use of suspended lead during manual PCI was associated with significantly less radiation exposure to the chest and head of operating physicians than traditional lead apparel (chest: 0.0 [0.1] µSv vs 0.4 [4.0] µSv, p<0.001; head: 0.5 [1.9] µSv vs 14.9 [51.5] µSv, p<0.001). Chest-level radiation exposure during robotic PCI performed in combination with suspended lead was 0.0 [0.0] µSv, which was significantly less chest exposure than manual PCI performed with traditional lead (p<0.001) or suspended lead (p=0.046). In robotic PCI the median head-level exposure was 0.1 [0.2] µSv, which was 99.3% less than manual PCI performed with traditional lead (p<0.001) and 80.0% less than manual PCI performed with suspended lead (p<0.001). CONCLUSIONS: Utilization of suspended lead and robotics were observed to result in significantly less radiation exposure to the chest and head of operating physicians during PCI.

Multimodality Intracoronary Imaging With Near-Infrared Spectroscopy and Intravascular Ultrasound in Asymptomatic Individuals With High Calcium Scores.

BACKGROUND: This study sought to determine the frequency of large lipid-rich plaques (LRP) in the coronary arteries of individuals with high coronary artery calcium scores (CACS) and to determine whether the CACS correlates with coronary lipid burden. METHODS AND RESULTS: Combined near-infrared spectroscopy and intravascular ultrasound was performed in 57 vessels in 20 asymptomatic individuals (90% on statins) with no prior history of coronary artery disease who had a screening CACS ≥300 Agatston units. Among 268 10-mm coronary segments, near-infrared spectroscopy images were analyzed for LRP, defined as a bright yellow block on the near-infrared spectroscopy block chemogram. Lipid burden was assessed as the lipid core burden index (LCBI), and large LRP were defined as a maximum LCBI in 4 mm ≥400. Vessel plaque volume was measured by quantitative intravascular ultrasound. Vessel-level CACS significantly correlated with plaque volume by intravascular ultrasound (r=0.69; P<0.0001) but not with LCBI by near-infrared spectroscopy (r=0.24; P=0.07). Despite a high CACS, no LRP was detected in 8 (40.0%) subjects. Large LRP having a maximum LCBI in 4 mm ≥400 were infrequent, found in only 5 (25.0%) of 20 subjects and in only 5 (1.9%) of 268 10-mm coronary segments analyzed. CONCLUSIONS: Among individuals with a CACS ≥300 Agatston units mostly on statins, CACS correlated with total plaque volume but not LCBI. This observation may have implications on coronary risk among individuals with a high CACS considering that it is coronary LRP, rather than calcification, that underlies the majority of acute coronary events.

Percutaneous coronary intervention using a combination of robotics and telecommunications by an operator in a separate physical location from the patient: an early exploration into the feasibility of telestenting (the REMOTE-PCI study).

AIMS: The present study explores the feasibility of telestenting, wherein a physician operator performs stenting on a patient in a separate physical location using a combination of robotics and telecommunications. METHODS AND RESULTS: Patients undergoing robotic stenting were eligible for inclusion. All manipulations of guidewires, balloons, and stents were performed robotically by a physician operator located in an isolated separate room outside the procedure room housing the patient. Communication between the operating physician and laboratory personnel was via telecommunication devices providing real-time audio and video connectivity. Among 20 patients who consented to participate, technical success, defined as successful advancement and retraction of guidewires, balloons, and stents by the robotic system without conversion to manual operation, was achieved in 19 of 22 lesions (86.4%). Procedural success, defined as <30% residual stenosis upon completion of the procedure in the absence of death or repeat revascularisation prior to hospital discharge, was achieved in 19 of 20 patients (95.0%). There were no deaths or repeat revascularisations prior to hospital discharge. CONCLUSIONS: To the best of our knowledge, the present study is the first to explore the feasibility of telestenting. Additional studies are required to determine if future advancements in robotics will facilitate telestenting over greater geographic distances.