2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging—Best Practices for Safety and Effectiveness, Part 2: Radiological Equipment Operation, Dose-Sparing Methodologies, Patient and Medical Personnel Protection

Radiation Exposure, Training, and Safety in Cardiology

Exposure to ionizing radiation is an inherent occupational health hazard in clinical cardiology. Health risks have been reported previously, including predilection to cancer. In addition, orthopedic injury due to prolonged wearing of heavy protective lead aprons, which are mandatory to reduce radiation risk, have been extensively documented. Cardiology as a specialty has grown with rising volumes of increasingly complex procedures. This includes electrophysiological, coronary, and structural intervention, advanced heart failure/transplant management, and diagnostic imaging. Both the operator as well imaging specialists are exposed to radiation, particularly in structural interventions where interventional cardiologists and structural imagers work closely. Increasingly, women interested in cardiology may deselect the field due to radiation concerns. This expert document highlights the risks of radiation exposure in cardiology, including practical tips within various subspecialty fields such as interventional/structural cardiology, electrophysiology, imaging, advanced heart failure, and pediatric cardiology.

Statewide Initiative to Reduce Patient Radiation Doses During Percutaneous Coronary Intervention

BACKGROUND

Improved radiation safety practices are needed across hospitals performing percutaneous coronary intervention (PCI). This study was performed to assess the temporal trend in PCI radiation doses concurrent with the conduct of a statewide radiation safety initiative.

METHODS

A statewide initiative to reduce PCI radiation doses was conducted in Michigan between 2017 and 2021 and included focused radiation safety education, reporting of institutional radiation doses, and implementation of radiation performance metrics for hospitals. Using data from a large statewide registry, PCI discharges between July 1, 2016, and July 1, 2022, having a procedural air kerma (AK) recorded were analyzed for temporal trends. A multivariable regression analysis was performed to determine whether declines in procedural AK over time were attributable to changes in known predictors of radiation doses.

RESULTS

Among 131 619 PCI procedures performed during the study period, a reduction in procedural AK was observed over time, from a median dose of 1.46 (0.86-2.37) Gy in the first year of the study to 0.97 (0.56-1.64) Gy in the last year of the study (P<0.001). The proportion of cases with an AK ≥5 Gy declined from 4.24% to 0.86% over the same time period (P<0.0001). After adjusting for variables known to impact radiation doses, a 1-year increase in the date of PCI was associated with a 7.61% (95% CI, 7.38%-7.84%) reduction in procedural AK (P<0.0001).

CONCLUSIONS

Concurrent with the conduct of a statewide initiative to reduce procedural radiation doses, a progressive and significant decline in procedural radiation doses was observed among patients undergoing PCI in the state of Michigan.

The Fluoroless Future in Electrophysiology: A State-of-the-Art Review

Fluoroscopy has always been the cornerstone imaging method of interventional cardiology procedures. However, radiation exposure is linked to an increased risk of malignancies and multiorgan diseases. The medical team is even more exposed to X-rays, and a higher incidence of malignancies was reported in this professional group. In the last years, X-ray exposure has increased rapidly, involving, above all, the medical team and young patients and forcing alternative fluoroless imaging methods. In cardiac electrophysiology (EP) and pacing, the advent of 3D electroanatomic mapping systems with dedicated catheters has allowed real-time, high-density reconstruction of both heart anatomy and electrical activity, significantly reducing the use of fluoroscopy. In addition, the diffusion of intracardiac echocardiography has provided high anatomical resolution of moving cardiac structures, providing intraprocedural guidance for more complex catheter ablation procedures. These methods have largely demonstrated safety and effectiveness, allowing for a dramatic reduction in X-ray delivery in most arrhythmias' ablations. However, some technical concerns, as well as higher costs, currently do not allow their spread out in EP labs and limit their use to only procedures that are considered highly complex and time-consuming and in young patients. In this review, we aim to update the current employment of fluoroless imaging in different EP procedures, focusing on its strengths and weaknesses.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.

Clinical application of percutaneous left atrial appendage occlusion guided only by transesophageal echocardiography without fluoroscopy and angiography in the patients with nonvalvular atrial fibrillation

BACKGROUND AND AIM

The objective of this study was to understand the clinical efficacy and application of the percutaneous left atrial appendage occlusion (PLAAO) guided only by the transesophageal echocardiography (TEE) in patients with nonvalvular atrial fibrillation (NVAF), without using the fluoroscopy and angiography.

METHODS

During the time period of this study from June 2020 to June 2021, 32 patients underwent PLAAO and all underwent a TEE guided approach. The anatomical features of the left atrial appendage (LAA) were evaluated and observed by TEE before and during the procedure. LAA occluder device was selected for the appropriate size. Intraoperative TEE guided and monitored the process of PLAAO in real-time, and also evaluated the stability and tightness of the occluder device, following monitored postoperative complications.

RESULTS

The PLAAO procedure was successful in all the patients. No serious complications like dislocation of the occluder and embolism were seen. Postoperative TEE demonstrated that the PLAAO occluder devices were in a good position without residual shunting.

CONCLUSIONS

PLAAO only guided by TEE may become a safe and reliable surgical procedure, which can protect surgeons and patients from radiation, and can gradually become a novel surgical method of PLAAO with the practical application value.

Conventional fluoroscopy-guided versus zero-fluoroscopy catheter ablation of supraventricular tachycardias

Purpose

The aim of this study was to evaluate the safety and efficacy of zero-fluoroscopy (ZF) catheter ablation (CA) for supraventricular tachycardias (SVT).

Methods

584 consecutive patients referred to our institution for CA of SVT were analysed. Patients were categorised into two groups; zero-fluoroscopy (ZF) group and conventional fluoroscopy (CF) group. The ZF group was further divided into two subgroups (adults and paediatric). Patient characteristics, procedural information, and follow-up data were compared.

Results

The ZF group had a higher proportion of paediatric patients (42.2% vs 0.0%; p < 0.001), resulting in a younger age (30.9 ± 20.3 years vs 52.7 ± 16.5 years; p < 0.001) and lower BMI (22.8 ± 5.7 kg/m2 vs 27.0 ± 5.4 kg/m2; p < 0.001). Procedure time was shorter in the ZF group (94.2 ± 50.4 min vs 104.0 ± 54.0 min; p = 0.002). There were no major complications and the rate of minor complications did not differ between groups (0.0% vs 0.4%; p = 0.304). Acute procedural success as well as the long-term success rate when only the index procedure was considered did not differ between groups (92.5% vs 95.4%; p = 0.155; 87.1% vs 89.2%; p = 0.422). When repeated procedures were included, the long-term success rate was higher in the ZF group (98.3% vs 93.5%; p = 0.004). The difference can be partially explained by the operators' preferences.

Conclusion

The safety and efficacy of ZF procedures in adult and paediatric populations are comparable to that of CF procedures.

The use of digital magnification to reduce radiation dose in the cardiac catheter laboratory

OBJECTIVES

To audit whether using magnification of images by use of a large viewing screen using digital matrix magnification which enlarges the image by 33% without using the X-ray machine zoom magnification protocols on a Siemens Artis Zee X-ray machine in a cardiac catheter laboratory results in a reduction of kerma-area product (KAP) for both diagnostic and interventional procedures. This reduction was predicted in an in vitro study in our laboratory, which has previously shown a 20.4% reduction in KAP.

METHODS

A retrospective analysis was conducted of the radiation exposure to compare the measured KAP recorded during the period when conventional magnification with automatic brightness and dose control was used on a Siemens Artis Zee X-ray machine with a flat panel detector and when magnification settings were avoided by using a large screen to enlarge and project a non-magnified image by digital magnification. The analysis was carried out for patients having a diagnostic coronary angiogram and those having an interventional coronary procedure.

RESULTS

For diagnostic coronary angiograms the median KAP per procedure in the period using conventional magnification was 2124.5 µGy.m² compared to 1401 µGy.m² when image matrix magnification was used, a 34% reduction (p < 0.0001). For interventional coronary procedures, the median KAP per procedure in the period using conventional magnification was 3791 µGy.m² compared to 2568.5 µGy.m² when image matrix magnification was used, a 32% reduction (p < 0.0001).

CONCLUSION

Avoiding using conventional magnification in the cardiac catheter laboratory and using a large screen to magnify images was associated with a statistically significant greater than 30% reduction in KAP.

ADVANCES IN KNOWLEDGE

This paper is the proof in clinical practice of a theoretical conclusion that radiation dose (KAP) is reduced by use of Image matrix magnification using a large viewing screen without the need to use X-ray tube magnification without significant loss of image resolution in interventional cardiology. The same approach will be useful in interventional radiology.

Impact of Active Esophageal Cooling on Fluoroscopy Usage During Left Atrial Ablation

Risks to collateral structures exist with radiofrequency (RF) ablation of the left atrium to obtain pulmonary vein isolation (PVI) for the treatment of atrial fibrillation. Passive luminal esophageal temperature (LET) monitoring is commonly utilized, but increasing data suggest limited benefits with LET monitoring. In contrast, active cooling of the esophagus has been shown to significantly reduce esophageal injury. Active cooling of the esophagus also avoids the need for stopping and repositioning an LET probe during use, which may reduce the need for fluoroscopy use. This study aimed to measure the impact on fluoroscopy use during RF ablation with esophageal cooling using a dedicated cooling device in a low-fluoroscopy practice. All patients who underwent PVI over a one-year timeframe by a single provider were analyzed. Patients undergoing PVI prior to the incorporation of an esophageal cooling protocol into standard ablation practice were treated with traditional LET monitoring. Patients treated after this point received active esophageal cooling, in which no LET monitoring is utilized. A total of 280 patients were treated; 91 patients were treated using LET monitoring, and 189 patients were treated with esophageal cooling. The mean total fluoroscopy time before the implementation of the esophageal cooling protocol in 91 patients was 194 seconds [standard deviation (SD): 182 seconds] per case, with a median of 144 seconds. The mean total fluoroscopy time after implementation in 189 patients was 126 seconds (SD: 120 seconds) per case with a median of 96 seconds, representing a reduction of 35% per case (p < 0.0001, Mann-Whitney U test). In this largest study to date of active esophageal cooling during PVI, a 35% reduction in fluoroscopy time compared with patients who received LET monitoring was found. This reduction was seen despite an already low fluoroscopy usage rate in place.

Radiation awareness in an Italian multispecialist sample assessed with a web-based survey

INTRODUCTION

The awareness of radiation doses and risks, also during interventional cardiology procedures, is essential today in order to apply the risk-benefit assessment and to reinforce the principles of justification and optimisation in clinical practice.

METHODS

A voluntary survey with 10 questions and multiple-choice answers was run on a popular cardiology website (www.cardiolink.it) independently by a scientific publisher, in order to evaluate the contemporary level of radiation awareness in a multi-speciality sample of physicians in Italy.

RESULTS

One thousand eight hundred and sixty-one physicians completed the test. The survey showed good results since both prescribers and practitioners (mostly cardiologists) working in Italy are largely aware of the cancer and non-cancer risks of medical radiation use, regardless of their subspecialty background.

CONCLUSION

Physicians are largely aware of the cancer and non-cancer risks of medical radiation use, regardless of their subspecialty background. However, there is still broad space for improvement; in the future, the awareness of radiation risk is a prerequisite to create a culture of respect for radiation hazard and a commitment to minimise exposure and maximise protection.

Can the Coronary Artery Calcium Score Scan Reduce the Radiation Dose in Coronary Computed Tomography Angiography?

RATIONALE AND OBJECTIVES

Radiation exposure from coronary computed tomography angiography (CCTA) remains a cause for concern. The objective of this study was to investigate whether using the coronary artery calcium score scan (CACS) would reduce the radiation dose for CCTA scanning and the overall radiation exposure (ORE).

MATERIALS AND METHODS

In total, 256 patients were examined with a third-generation dual-source CT (n = 200) or 256-row CT (n = 56), among whom 105 (Group A) and 28 patients (Group B), respectively, underwent CCTA with CACS for field of view planning. The remaining patients, with the scout view for field of view planning, constituted Group A1 and B1. The scanning parameter settings were standardized between groups.

RESULTS

Shorter scan lengths were observed in Group A (9.98 ± 0.79 cm) compared to Group A1 (13.64 ± 1.79 cm; p < 0.001), which also resulted in a lower dose-length product (DLP) in Group A (115.04 ± 64.13) relative to Group A1 (138.67 ± 68.87; p < 0.05). Similarly, shorter scan lengths were found in Group B (14.92 ± 1.17 cm) compared to Group B1 (15.79 ± 0.63 cm; p = 0.001); this resulted in a lower DLP (322.07 ± 45.39) compared to Group B1 (354.34 ± 65.27; p = 0.036). The CACS resulted in an increase in ORE in both groups.

CONCLUSION

CACS may have a critical role in the reduction of radiation dose in CCTA scanning, but the potential effectiveness of CACS in reducing ORE is weak.

The structural heart disease interventional imager rationale, skills and training: a position paper of the European Association of Cardiovascular Imaging

Percutaneous therapeutic options for an increasing variety of structural heart diseases (SHD) have grown dramatically. Within this context of continuous expansion of devices and procedures, there has been increased demand for physicians with specific knowledge, skills, and advanced training in multimodality cardiac imaging. As a consequence, a new subspecialty of ‘Interventional Imaging’ for SHD interventions and a new dedicated professional figure, the ‘Interventional Imager’ with specific competencies has emerged. The interventional imager is an integral part of the heart team and plays a central role in decision-making throughout the patient pathway, including the appropriateness and feasibility of a procedure, pre-procedural planning, intra-procedural guidance, and post-procedural follow-up. However, inherent challenges exist to develop a training programme for SHD imaging that differs from traditional cardiovascular imaging pathways. The purpose of this document is to provide the standard requirements for the training in SHD imaging, as well as a starting point for an official certification process for SHD interventional imager.

Catheter strategy to ease the procedure and reduce radiation exposure when requiring neck access

Objectives

To assess the potential occupational radiation reduction and technical feasibility in patients rotated 180° (upside-down) when requiring neck access for transcervical or trans-subclavian catheterisation.

Methods

Upside-down positioning is defined as rotating patients in supine position by 180°, so that the feet come to rest where the head would otherwise be. We retrospectively evaluated all these procedures performed between March 2016 and May 2019. Furthermore, two different phantoms (paediatric and adult) were used prospectively to quantify the occupational dose between conventional or upside-down positioning. In this context, ambient dose equivalents were measured using real-time dosimeters. Three different projection angles were applied.

Results

44 patients with median age and body weight of 1.0 year (range 0–56) and 9.5 kg (range 1.3–74.3) underwent 63 procedures positioned upside-down. This position proved advantageous for practical reasons, since the length of the examination table could be optimally used. Additionally, it resulted in a significantly lower overall ambient dose equivalent for the primary operator (PO) of 94.8% (mean: 2569±807 vs 135±23 nSv; p<0.01) in the adult, and of 65.5% (mean: 351±104 vs 121±56 nSv; p<0.01) in the paediatric phantom, respectively.

Conclusion

Upside-down positioning facilitates handling in a straightforward manner when access from the neck is required. Moreover, it significantly reduces local radiation exposure for the PO in the paediatric and, most impressively, in the adult phantom.

Efficacy of MAVIG X-Ray Protective Drapes in Reducing Operator Radiation Dose in the Cardiac Catheterization Laboratory: A Randomized Controlled Trial

BACKGROUND

Interventional cardiologists are occupationally exposed to high doses of ionizing radiation. The MAVIG X-ray protective drape (MXPD) is a commercially available light weight, lead-free shield placed over the pelvic area of patients to minimize operator radiation dose. The aim of this study was to examine the efficacy of the MXPD during routine cardiac catheterization, including percutaneous coronary interventions.

METHODS

We performed a prospective, randomized controlled study comparing operator radiation dose during cardiac catheterization and percutaneous coronary intervention (n=632) with or without pelvic MXPD. We measured operator radiation dose at 4 sites: left eye, chest, left ring finger, and right ring finger. The primary outcomes were the difference in first operator radiation dose (µSv) and relative dose of the first operator (radiation dose normalized for dose area product) at the level of the chest in the 2 groups.

RESULTS

The use of the MXPD was associated with a 50% reduction in operator radiation dose (median dose 30.5 [interquartile range, 23.0-39.7] µSv in no drape group versus 15.3 [interquartile range, 11.1-20.0] µSv in the drape group; P<0.001) and a 57% reduction in relative operator dose (P<0.001). The largest absolute reduction in dose was observed at the left finger (median left finger dose for the no drape group was 104.9 [75.7-137.4] µSv versus 41.9 [32.6-70.6] µSv in the drape group; P<0.001).

CONCLUSIONS

The pelvic MXPD significantly reduces first operator radiation dose during routine cardiac catheterization and percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT04285944.

Cardiac arrhythmia catheter ablation procedures guided by x-ray imaging: N-acetylcysteine protection against radiation-induced cellular damage (CARAPACE study): study design

PURPOSE

Catheter ablation (CA) procedures are characterized by exposure to ionizing radiations (IR). IR can cause DNA damage and may lead to carcinogenesis if not efficiently repaired. The primary endpoint of this study is to investigate whether intravenous administration of N-acetylcysteine prior to CA procedure may prevent systemic oxidative stress and genomic DNA damage induced by exposure to IR.

METHODS

The "Cardiac Arrhythmia catheter ablation procedures guided by x-Ray imaging: N-Acetylcysteine Protection Against radiation induced Cellular damagE" (CARAPACE) study is a prospective, randomized, single-blinded, parallel-arm monocenter study enrolling 550 consecutive patients undergoing CA at the Arrhythmology Unit of Centro Cardiologico Monzino (CCM). Inclusion criteria are age ≥ 18, indication for CA procedure guided by IR imaging, and written informed consent. IR levels will be measured via fluoroscopy time, effective dose, and dose area product. Glutathione and glutathione disulfide concentrations will be measured, and urinary levels of 8-iso-prostaglandin-F_2α and 8-hydroxy-2-deoxyguanosine will be quantified. The enrolled patients will be randomized 1:1 to the N-acetylcysteine group or to the control group.

RESULTS

We expect that pre-operative administration of N-acetylcysteine will prevent IR-induced systemic oxidative stress. The study will provide data on oxidative DNA damage assessed by urinary 8-hydroxy-2-deoxyguanosine levels and direct evidence of genomic DNA damage in blood cells by comet assay.

CONCLUSION

Catheter ablation procedures can lead to IR exposure and subsequent DNA damage. N-acetylcysteine administration prior to the procedure may prevent them and therefore lead to less possible complications.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT04154982).

Cardiac catheterization real-time dynamic radiation dose measurement to estimate lifetime attributable risk of cancer

Cardiac catheterization procedure is the gold standard to diagnose and treat cardiovascular disease. However, radiation safety and cancer risk remain major concerns. This study aimed to real-time dynamic radiation dose measurement to estimate lifetime attributable risk (LAR) of cancer incidence and mortality in operators. Coronary angiography (CA) with percutaneous coronary intervention (PCI), CA, and others (radiofrequency ablation, pacemaker and defibrillator implantation) procedures with different beam directions, were undertaken on x-ray angiography system. A real-time electronic personal dosimeter (EPD) system was used to measure the radiation dose of staff during all procedures. We followed the Biological Effects of Ionizing Radiation (BEIR) VII report to estimate the LAR of all cancer incidence and mortality. Primary operators received radiation dose in CA with PCI, CA, and others procedures were 59.33 ± 95.03 μSv, 39.81 ± 103.85 μSv, and 21.92 ± 37.04 μSv, respectively. As to the assistant operators were 30.03 ± 55.67 μSv, 14.67 ± 14.88 μSv, and 4 μSv, respectively. LAR of all cancer incidences for staffs aged from 18 to 65 are varied from 0.40% for males to 1.50% for females. LAR of all cancer mortality for staffs aged from 18 to 65 are varied from 0.22% for males to 0.83% for females. Our study provided an easy, real-time and dynamic radiation dose measurement to estimate LAR of cancer for staff during the cardiac catheterization procedures. The LAR for all cancer incidence is about twice that for cancer mortality. Although the radiation doses of staff are lower during each procedure, the increased years of service leads to greater radiation risk to the staff.

The difference in dose and image quality between magnification methods used after the introduction of larger 60-inch operator screens

OBJECTIVE

To determine whether the use of display matrix magnification on larger operator screens without the use of conventional magnification can reduce radiation dose to the patient, and what effect it would have on image quality.

METHODS

The kerma-area product (KAP) resulting from standard projections in cardiac angiography were measured when an anthropomorphic phantom was imaged using conventional magnification method and display matrix magnification. The image quality was also evaluated by three observers using a TOR 18FG test tool for both magnification method.

RESULTS

The mean radiation KAP for the seven views with conventional magnification was 36.65 µGy m-2 whilst a reduction in KAP of 20.4% is possible using display matrix magnification (p < 0.05). The image resolution during acquisition was identical between both methods and only slightly reduced for the display matrix (1.6 LP mm-1) compared to conventional magnification (1.8 LP mm-1) when images were stored and retrieved on a Picture Archiving and Communication Systems (PACS) system. Both methods retained the same low-contrast detectability to PACS, with only a slight increase in detectability of 18 for display matrix magnification compared to 17 for conventional.

CONCLUSION

Using display matrix magnification instead of conventional equipment magnification significantly reduces radiation does in all standard cardiac views without reducing image quality for the operator. This reduction in radiation dose is significant (p < 0.05) for the patients. The resolution did not change during acquisition, but contrast improved slightly (0.9% threshold contrast), but lost resolution of 0.2 LP mm-1 when archived to PACS.

ADVANCES IN KNOWLEDGE

This is a new method of reducing significant dose to the patient during cardiology examinations and may encourage further studies in other fluoroscopy lead examination to see if it could work for them.

Team perception of the radiation safety climate in the hybrid angiography suite: A cross-sectional study

BACKGROUND

Good radiation safety practice in the angiosuite is essential to protect patients and healthcare workers. Most strategies aim to advance radiation safety through technological upgrades and educational initiatives. However, safety literature suggests that additional ways to improve radiation safety in the angiosuite do exist. The safety climate reflects the way team members perceive various key characteristics of their work environment and is closely related to relevant safety outcomes. A specific 'radiation safety climate' has not been described nor studied in the hybrid angiosuite. This study explores the radiation safety climate in the hybrid angiosuite and its relation to team members' radiation safety behavior, knowledge and motivation.

MATERIALS AND METHODS

Vascular surgeons, fellows/trainees and operating room nurses active in the angiosuite at five hospitals were invited to complete an online self-report questionnaire assessing the radiation safety climate (28 items); radiation safety behavior; radiation safety knowledge and radiation safety motivation. Relations between climate scores and behavior were investigated using Pearson correlations. Mediation was analyzed using the Baron and Kenny analysis. P-Values < 0.05 were considered statistically significant.

RESULTS

No major differences were identified in total radiation safety climate scores between centers or team member functions. Scale reliability for radiation safety climate was good to excellent (α > 0.663). Total radiation safety climate scores were positively related to the radiation safety behavior score (r = 0.403; p = 0.015). This relation was partially mediated by radiation safety knowledge (β = 0.1730; 95% CI: [0.0475; 0.3512]), while radiation safety motivation did not act as a mediator: (β = 0.010; 95% CI: [-0.0561; 0.0998]).

CONCLUSION

A well-developed radiation safety climate in the hybrid angiosuite fosters positive radiation safety behaviors, which may partially be explained through improved radiation safety knowledge transfer. Further research on (radiation) safety climate and its impact on radiation safety-related outcome measures for patients is recommended.

Safety and efficacy of zero fluoroscopy transseptal puncture with different approaches

INTRODUCTION

Atrial fibrillation (AF) ablation requires access to the left atrium (LA) via transseptal puncture (TP). TP is traditionally performed with fluoroscopic guidance. Use of intracardiac echocardiography (ICE) and three-dimensional mapping allows for zero fluoroscopy TP.

OBJECTIVE

To demonstrate safety and efficacy of zero fluoroscopy TP using multiple procedural approaches.

METHODS

Patients undergoing AF ablation between January 2015 and November 2017 at five institutions were included. ICE and three-dimensional mapping were used for sheath positioning and TP. Variable technical approaches were used across centers including placement of J wire in the superior vena cava with ICE guidance followed by dragging down the transseptal sheath into the interatrial septum, or guiding the transseptal sheath directly to the interatrial septum by localizing the ablation catheter with three-dimensional mapping and replacing it with the transseptal needle once in position. In patients with pacemaker/implantable cardiac defibrillator leads, pre-/poststudy device interrogation was performed.

RESULTS

A total of 747 TPs were performed (646 patients, age 63.1 ± 13.1, 67.5% male, LA volume index 34.5 ± 15.8 mL/m² , ejection fraction 57.7 ± 10.9%) with 100% success. No punctures required fluoroscopy. Two pericardial effusions, two pericardial tamponades requiring pericardiocentesis, and one transient ischemic attack were observed during the overall ablation procedure, with a total complication rate of 0.7%. There were no other periprocedural complications related to TP, including intrathoracic bleeding, stroke, or death both immediately following TP and within 30 days of the procedure. In patients with intracardiac devices, no device-related complications were observed.

CONCLUSION

TP can be safely and effectively performed without the need for fluoroscopy.

Occupational and patient radiation doses in a modern cardiac electrophysiology laboratory

PURPOSE

Technological advancements have greatly expanded the field of cardiac electrophysiology, requiring greater demands on imaging systems and potentially delivering higher radiation doses to patients and operators. With little contemporary research on occupational and patient radiation risk in the electrophysiology laboratory, the aim of this study was to analyze radiation doses, including occupational fetal doses, over approximately the last decade. We benchmarked the occupational data to our patient radiation dose data to allow for comparison and to put into perspective the associated radiation risks.

METHODS

Occupational radiation dosimetry analyzed included data from an 11-year period for physicians, a 7-year period for nurses, and a 9-year period for fetal doses. Patient-related dose metrics over an 8-year period were also analyzed.

RESULTS

In the physician and nursing groups, there was a nearly 70% decrease in the average occupational radiation doses over the given periods. Within the electrophysiology department, the average fetal occupational doses were very low, close to 0 μSv. The average reference point air kerma per patient for all electrophysiology procedures decreased from nearly 600 mGy/procedure in 2010 to just over 100 mGy/procedure in 2017.

CONCLUSIONS

Patient and occupational radiation doses in our laboratories significantly decreased over the periods analyzed as a result of clinical and technical staff efforts as well as advances in imaging technology. The radiation-related risk to individuals working in our electrophysiology laboratories, including pregnant women, is very low. Data reported herein could be used by other institutions to evaluate their occupational and patient radiation safety practices.

The new clinical standard of integrated quadruple stress echocardiography with ABCD protocol

BACKGROUND

The detection of regional wall motion abnormalities is the cornerstone of stress echocardiography. Today, stress echo shows increasing trends of utilization due to growing concerns for radiation risk, higher cost and stronger environmental impact of competing techniques. However, it has also limitations: underused ability to identify factors of clinical vulnerability outside coronary artery stenosis; operator-dependence; low positivity rate in contemporary populations; intermediate risk associated with a negative test; limited value of wall motion beyond coronary artery disease. Nevertheless, stress echo has potential to adapt to a changing environment and overcome its current limitations.

INTEGRATED-QUADRUPLE STRESS-ECHO

Four parameters now converge conceptually, logistically, and methodologically in the Integrated Quadruple (IQ)-stress echo. They are: 1- regional wall motion abnormalities; 2-B-lines measured by lung ultrasound; 3-left ventricular contractile reserve assessed as the stress/rest ratio of force (systolic arterial pressure by cuff sphygmomanometer/end-systolic volume from 2D); 4- coronary flow velocity reserve on left anterior descending coronary artery (with color-Doppler guided pulsed wave Doppler). IQ-Stress echo allows a synoptic functional assessment of epicardial coronary artery stenosis (wall motion), lung water (B-lines), myocardial function (left ventricular contractile reserve) and coronary small vessels (coronary flow velocity reserve in mid or distal left anterior descending artery). In "ABCD" protocol, A stands for Asynergy (ischemic vs non-ischemic heart); B for B-lines (wet vs dry lung); C for Contractile reserve (weak vs strong heart); D for Doppler flowmetry (warm vs cold heart, since the hyperemic blood flow increases the local temperature of the myocardium). From the technical (acquisition/analysis) viewpoint and required training, B-lines are the kindergarten, left ventricular contractile reserve the primary (for acquisition) and secondary (for analysis) school, wall motion the university, and coronary flow velocity reserve the PhD program of stress echo.

CONCLUSION

Stress echo is changing. As an old landline telephone with only one function, yesterday stress echo used one sign (regional wall motion abnormalities) for one patient with coronary artery disease. As a versatile smart-phone with multiple applications, stress echo today uses many signs for different pathophysiological and clinical targets. Large scale effectiveness studies are now in progress in the Stress Echo2020 project with the omnivorous "ABCD" protocol.

[Radiation reduction in interventional electrophysiology : Results from operators with different levels of experience]

BACKGROUND

Radiation exposure in the catherization laboratory is associated with significant health risks. It is unclear whether a reduction of radiation exposure with the use of "near-zero fluoroscopy" protocols is possible when applied by less experienced operators.

METHODS

Consecutive ablation procedures with the use of a 3D mapping system were analyzed. Three time periods were analyzed. During the first period (standard), no specific radiation-reduction protocol was used. During the second period (initial phase of radiation reduction) a near "near-zero fluoroscopy" protocol was implemented; however, the majority of procedures were performed by an expert. During the third period (routine use of radiation reduction), less experienced operators (fellow and beginner) performed a growing number of procedures with the "near-zero fluoroscopy" protocol.

RESULTS

In all, 290 procedures were analyzed. After implementation of a radiation-reduced protocol, a significant reduction of radiation exposure was observed (standard 850 ± 831.7 vs. initial phase 197.2 ± 481.8 μGy/m², p < 0.001, and vs. routine use 283 ± 493.8 μGy/m², p < 0.001). No significant difference was observed between the initial phase and routine phase (p = 1). Over the three periods, the proportion of procedures performed by less experienced operators grew significantly for complex (fellow: 0% vs. 10% vs. 30%; p < 0.001) and noncomplex procedures (fellow: 30% vs. 39% vs. 49%; beginner: 15% vs. 38% vs. 34%; p = 0.002). Complication rates were not significantly different.

CONCLUSIONS

Implementation of a radiation-reduced protocol leads to a significant reduction of radiation exposure even in less experienced operators during training.