Canadian Cardiovascular Society position statement on radiation exposure from cardiac imaging and interventional procedures

National Trends of Gender Disparity in Canadian Cardiovascular Society Guideline Authors, 2001-2020

Background

The level of representation of women in cardiology remains low compared to that of men, particularly in leadership positions. We evaluated gender disparity in the authorship of Canadian Cardiovascular Society (CCS) guidelines.

Methods

All CCS guidelines from 2001-2020 were identified. Gender was assessed based on pronoun use in the biographies and social media of the authors. Only primary panel authors were included in our analysis. Stratified analyses were performed based on subspecialties.

Results

A total of 76 guidelines were identified, with 1172 authors (26% women, 74% men, P < 0.0001), with no significant change in percentage of women authors over 2 decades, (37.1% in 2001, 36.3% in 2020, P = 0.34). Inclusion of women as authors occurred less frequently than inclusion of men in general cardiology guidelines (20.1% vs 79.9%, P < 0.0001) and all subspecialties—heart failure (36.4% vs 63.6%, P < 0.0001), interventional cardiology (12.6% vs 87.4%, P < 0.0001), electrophysiology (20.2% vs 79.8%, P < 0.0001), and pediatric cardiology (41.7% vs 58.3%, P = 0.02). It was less likely for women to be a chair or cochair of a guideline writing committee, compared with men (20.1% vs 79.8%, P < 0.0001). There were 609 unique authors (25.6% women, 74.4% men, P < 0.0001), 542 unique medical doctorate (MD) authors (20.7% women, 79.3% men, P < 0.0001), and 67 unique non-MD authors (65.7% women, 34.3% men, P = 0.0003).

Conclusions

There is a persistent shortfall in the inclusion of women authors for CCS guidelines, which has not changed over time. Further efforts are required to promote women's inclusion in leadership roles, which may lead to authorship of the guidelines.

The Emergent Pelvic Artery Embolization in the Management of Postpartum Hemorrhage: A Systematic Review and Meta-analysis

Importance

Postpartum hemorrhage (PPH) is an emergent obstetric complication and the leading cause of maternal mortality. Pelvic arterial embolization (PAE) is an effective treatment for intractable PPH. However, a unique protocol has not been accepted in obstetrical practice.

Objective

To evaluate its efficiency, safety, complications, and outcomes, we conducted a systematic review and meta-analysis of PAE for PPH in the literature.

Evidence Acquisition

The Medline, the database of abstract of reviews, the index to allied health literature, and the Chinese database Sino-Med were searched on March 31, 2020, for studies on PAE for PPH. The data for PAE indication, agents, arteries, success rate, complications, and outcomes were extracted and syncretized for meta-analysis.

Results

From 1075 identified articles, 113 abstracts or full articles were retrieved and 43 studies were finally identified as meeting the including criteria. The results demonstrated that the indications for PAE were as follows: uterine atony, placental abnormality, delivery tract injury, disseminated intravascular coagulation, arteriovenous malformation, and vaginal hematoma. The embolization agents mostly in order were gelatin sponge particles, polyvinyl alcohol particles, Gelfoam, N-butyl cyanoacrylate, microcoil, and glue; for arteries, they were mostly uterine artery and internal iliac artery. The clinical success rate was 90.5%, whereas the technical success rate was 99.3%. The most common complications of PAE were postembolization syndrome and menstrual abnormality.

Conclusions and Relevance

The emergent PAE is a safe and effective method with high success rate in life-threatening PPH management. Gelatin sponge granules measuring 500 to 1000 μm in diameter have safe results. Pelvic arterial embolization may affect the recovery of menses and increase PPH in the subsequent pregnancy, but there was no noted correlation with fetal growth restriction.

Fluoroscopy usage in contemporary interventional electrophysiology: Insights from a European registry

Background

Fluoroscopy has been an essential part of every electrophysiological procedure since its inception. However, till now no clear standards regarding acceptable x‐ray exposure nor recommendation how to achieve them have been proposed.

Hypothesis

Current norms and quality markers required for optimal clinical routine can be identified.

Methods

Centers participating in this Europe‐wide multicenter, prospective registry were requested to provide characteristics of the center, operators, technical equipment as well as procedural settings of consecutive cases.

Results

Twenty‐five centers (72% university clinics, with a mean volume of 526 ± 348 procedures yearly) from 14 European countries provided data on 1788 cases [9% diagnostic procedures (DP), 38% atrial fibrillation (AF) ablations, 44% other supraventricular (SVT) ablations, and 9% ventricular ablations (VT)] conducted by 95 operators (89% male, 41 ± 7 years old).

Mean dose area product (DAP) and time was 304 ± 608 cGy*cm², 3.6 ± 4.8 minutes, 1937 ± 608 cGy*cm², 15.3 ± 15.5 minutes, 805 ± 1442 cGy*cm², 10.6 ± 10.7 minutes, and 1277 ± 1931 cGy*cm², 10.4 ± 12.3 minutes for DP, AF, SVT, and VT ablations, respectively. Seven percent of all procedures were conducted without any use of fluoroscopy.

Procedures in the lower quartile of DAP were performed more frequently by female operators (OR 1.707, 95%CI 1.257‐2.318, P = .001), in higher‐volume center (OR 1.001 per one additional procedure, 95%CI 1.000‐1.001, P = .002), with the use of 3D‐mapping system (OR 2.622, 95%CI 2.053‐3.347, P < .001) and monoplane x‐ray system (OR 2.945, 95%CI 2.149‐4.037, P < .001).

Conclusion

Exposure to ionizing radiation varies widely in daily practice for all procedure. Significant opportunities for harmonization of exposure toward the lower range has been identified.

Utilization of an Optimized Radiation Strategy in Primary Percutaneous Coronary Intervention for Patients with ST-Segment-Elevation Myocardial Infarction

Background

Recent reports about radiation risk gradually raised the safety concerns for interventional therapy. However, limited data exist on the optimized radiation strategy in primary percutaneous coronary intervention (P-PCI) for patients with ST-segment-elevation myocardial infarction (STEMI).

Methods

A total of 214 STEMI patients undergoing P-PCI were retrospectively analyzed. Patients were divided into the optimized radiation strategy (ORS) group (N = 151) and normal radiation strategy (NRS) group (N = 63) according to the radiation protocol utilized. The primary endpoint was the relative dose reduction of total air kerma. The secondary endpoint was 30-day major adverse cardiac and cerebrovascular events (MACCE), as a composite of all-cause death, reinfarction, ischemia-driven target vessel revascularization, and stroke.

Results

Patient groups were well matched for baseline characteristics. There were no differences in terms of age, body mass index, radial artery access, nonculprit vessel PCI, and fluoroscopy time between 2 groups. With optimized radiation strategy, a 40.9% radiation dose reduction (901.2 ± 628.7 mGy versus 1524.0 ± 866.6 mGy, p < 0.001) was obtained for total air kerma. No significant differences were found for 30-day MACCE between 2 groups (2.0% versus 1.6%, adjusted hazard ratio: 0.7, 95% confidence interval: 0.1 to 8.6, p=0.772).

Conclusion

With optimized radiation strategy, significant radiation dose reduction could be achieved in P-PCI for STEMI patients. It appears to be feasible and safe to carry out the optimized radiation strategy in P-PCI for STEMI patients.

Evaluation of a new ultralow-dose radiation protocol for electrophysiological device implantation: A near-zero fluoroscopy approach for device implantation

BACKGROUND

Radiation is one of the main hazards of electrophysiological device implantation, and insertion of cardiac resynchronization therapy (CRT) devices in particular is associated with high radiation doses.

OBJECTIVE

The purpose of this study was to evaluate the impact of a new ultralow-dose radiation protocol on radiation doses, success rate, and safety of electrophysiological device implantations.

METHODS

In 2018, we established a new ultralow-dose radiation protocol (reduced pulse width, increased thickness of minimum copper filters, reduced detector entrance dose, reduced pulse rate, optimized image postprocessing settings) for de novo device implantation at our hospital. A total of 1173 patients (11% single-chamber devices, 69% dual-chamber devices, 20% CRT devices) were analyzed. Five hundred twelve patients (44%) in the ultralow-dose group were compared to 661 patients (66%) treated during 2017 with a conventional low-dose protocol.

RESULTS

With the ultralow-dose radiation protocol, effective doses could be reduced by 59% (median 0.25 [interquartile range: 0.11-0.63] vs median 0.10 [interquartile range: 0.03-0.28] mSv; P <.0001) per procedure without a significant change in procedure time (P = .5). This dose reduction could be achieved without decreasing procedure success (P = 1) or increasing complication rate (P = .8). Male gender, higher body mass index, increased procedure and fluoroscopy times, and use of the conventional radiation protocol were independent predictors of higher radiation doses in multivariate regression analysis.

CONCLUSION

By establishing a new ultralow-dose radiation protocol, we could significantly decrease radiation exposure, reaching the lowest radiation doses for electrophysiological device implantation reported to date.

Safety and feasibility of a low frame rate protocol for percutaneous coronary intervention to chronic total occlusions: preliminary experience

AIMS

The present study aimed to evaluate the safety and feasibility of a low frame rate protocol for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A total of 192 consecutive patients who underwent CTO-PCI following the low frame rate protocol were analysed. The low frame rate protocol adopted reduced frame rates and the addition of copper and aluminium filters. Procedural outcomes, radiation dose and in-hospital outcomes were ascertained. Meanwhile, a phantom experiment was designed to measure the radiation dose reduction. Overall technical and procedural success rates were 91.1% (175) and 90.6% (174), respectively. The retrograde approach was attempted in 56 (29.2%) lesions. The mean air kerma (AK) radiation exposure, fluoroscopy time and contrast volume were 2.6±2.0 Gy, 50.3±34.3 min and 294.1±131.8 ml, respectively. In-hospital major adverse events occurred in one patient (0.5%) and procedural complications occurred in six patients (3.1%). In the phantom experiment, a remarkable radiation dose reduction could be achieved for AK, dose area product (DAP), simulated first and second operator radiation exposure (reduction of 72.5%, 69.8%, 60.9% and 59.6%, respectively) in cineangiography from this protocol.

CONCLUSIONS

Our results provide the primary evidence that it appears to be safe and feasible to carry out the low frame rate protocol for CTO-PCI.

X-Ray Exposure in Cardiac Electrophysiology: A Retrospective Analysis in 8150 Patients Over 7 Years of Activity in a Modern, Large-Volume Laboratory

Background

Only a few studies have systematically evaluated fluoroscopy data of electrophysiological and device implantation procedures. Aims of this study were to quantify ionizing radiation exposure for electrophysiological/device implantation procedures in a large series of patients and to analyze the x‐ray exposure trend over years and radiation exposure in patients undergoing atrial fibrillation ablation considering different technical aspects.

Methods and Results

We performed a retrospective analysis of all electrophysiological/device implantation procedures performed during the past 7 years in a modern, large‐volume laboratory. We reported complete fluoroscopy data on 8150 electrophysiological/device implantation procedures (6095 electrophysiological and 2055 device implantation procedures); for each type of procedure, effective dose and lifetime attributable risk of cancer incidence and mortality were calculated. Over the 7‐year period, we observed a significant trend reduction in fluoroscopy time, dose area product, and effective dose for all electrophysiological procedures (P<0.001) and a not statistically significant trend reduction for device implantation procedures. Analyzing 2416 atrial fibrillation ablations, we observed a significant variability of fluoroscopy time, dose area product and effective dose among 7 different experienced operators (P<0.0001) and a significant reduction of fluoroscopy use over time (P<0.0001) for all of them. Considering atrial fibrillation ablation techniques, fluoroscopy time was not different (P = 0.74) for radiofrequency catheter ablation in comparison with cryoablation, though cryoablation was still associated with higher dose area product and effective dose values (P<0.001).

Conclusions

Electrophysiological procedures involve a nonnegligible x‐ray use, leading to an increased risk of malignancy. Awareness of radiation‐related risk, together with technological advances, can successfully optimize fluoroscopy use.

Near zerO fluoroscopic exPosure during catheter ablAtion of supRavenTricular arrhYthmias: the NO-PARTY multicentre randomized trial

AIMS

Aim of this study was to compare a minimally fluoroscopic radiofrequency catheter ablation with conventional fluoroscopy-guided ablation for supraventricular tachycardias (SVTs) in terms of ionizing radiation exposure for patient and operator and to estimate patients' lifetime attributable risks associated with such exposure.

METHODS AND RESULTS

We performed a prospective, multicentre, randomized controlled trial in six electrophysiology (EP) laboratories in Italy. A total of 262 patients undergoing EP studies for SVT were randomized to perform a minimally fluoroscopic approach (MFA) procedure with the EnSiteTMNavXTM navigation system or a conventional approach (ConvA) procedure. The MFA was associated with a significant reduction in patients' radiation dose (0 mSv, iqr 0-0.08 vs. 8.87 mSv, iqr 3.67-22.01; P < 0.00001), total fluoroscopy time (0 s, iqr 0-12 vs. 859 s, iqr 545-1346; P < 0.00001), and operator radiation dose (1.55 vs. 25.33 µS per procedure; P < 0.001). In the MFA group, X-ray was not used at all in 72% (96/134) of cases. The acute success and complication rates were not different between the two groups (P = ns). The reduction in patients' exposure shows a 96% reduction in the estimated risks of cancer incidence and mortality and an important reduction in estimated years of life lost and years of life affected. Based on economic considerations, the benefits of MFA for patients and professionals are likely to justify its additional costs.

CONCLUSION

This is the first multicentre randomized trial showing that a MFA in the ablation of SVTs dramatically reduces patients' exposure, risks of cancer incidence and mortality, and years of life affected and lost, keeping safety and efficacy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01132274.

Society of Vascular and Interventional Neurology (SVIN) Stroke Interventional Laboratory Consensus (SILC) Criteria: A 7M Management Approach to Developing a Stroke Interventional Laboratory in the Era of Stroke Thrombectomy for Large Vessel Occlusions

Brain attack care is rapidly evolving with cutting-edge stroke interventions similar to the growth of heart attack care with cardiac interventions in the last two decades. As the field of stroke intervention is growing exponentially globally, there is clearly an unmet need to standardize stroke interventional laboratories for safe, effective, and timely stroke care. Towards this goal, the Society of Vascular and Interventional Neurology (SVIN) Writing Committee has developed the Stroke Interventional Laboratory Consensus (SILC) criteria using a 7M management approach for the development and standardization of each stroke interventional laboratory within stroke centers. The SILC criteria include: (1) manpower: personnel including roles of medical and administrative directors, attending physicians, fellows, physician extenders, and all the key stakeholders in the stroke chain of survival; (2) machines: resources needed in terms of physical facilities, and angiography equipment; (3) materials: medical device inventory, medications, and angiography supplies; (4) methods: standardized protocols for stroke workflow optimization; (5) metrics (volume): existing credentialing criteria for facilities and stroke interventionalists; (6) metrics (quality): benchmarks for quality assurance; (7) metrics (safety): radiation and procedural safety practices.

Impact of Center Experience on Patient Radiation Exposure During Transradial Coronary Angiography and Percutaneous Intervention: A Patient-Level, International, Collaborative, Multi-Center Analysis

Background

The adoption of the transradial (TR) approach over the traditional transfemoral (TF) approach has been hampered by concerns of increased radiation exposure—a subject of considerable debate within the field. We performed a patient‐level, multi‐center analysis to definitively address the impact of TR access on radiation exposure.

Methods and Results

Overall, 10 centers were included from 6 countries—Canada (2 centers), United Kingdom (2), Germany (2), Sweden (2), Hungary (1), and The Netherlands (1). We compared the radiation exposure of TR versus TF access using measured dose‐area product (DAP). To account for local variations in equipment and exposure, standardized TR:TF DAP ratios were constructed per center with procedures separated by coronary angiography (CA) and percutaneous coronary intervention (PCI). Among 57 326 procedures, we demonstrated increased radiation exposure with the TR versus TF approach, particularly in the CA cohort across all centers (weighted‐average ratios: CA, 1.15; PCI, 1.05). However, this was mitigated by increasing TR experience in the PCI cohort across all centers (r=−0.8; P=0.005). Over time, as a center transitioned to increasing TR experience (r=0.9; P=0.001), a concomitant decrease in radiation exposure occurred (r=−0.8; P=0.006). Ultimately, when a center's balance of TR to TF procedures approaches 50%, the resultant radiation exposure was equivalent.

Conclusions

The TR approach is associated with a modest increase in patient radiation exposure. However, this increase is eliminated when the TR and TF approaches are used with equal frequency—a guiding principle for centers adopting the TR approach.

In vivo characterization of metabotropic glutamate receptor type 5 abnormalities in behavioral variant FTD

Although the pathogenesis underlying behavioral variant frontotemporal dementia (bvFTD) has yet to be fully understood, glutamatergic abnormalities have been hypothesized to play an important role. The aim of the present study was to determine the availability of the metabotropic glutamate receptor type 5 (mGluR5) using a novel positron emission tomography (PET) radiopharmaceutical with high selectivity for mGluR5 ([(11)C]ABP688) in a sample of bvFTD patients. In addition, we sought to determine the overlap between availability of mGluR5 and neurodegeneration, as measured using [(18)F]FDG-PET and voxel-based morphometry (VBM). Availability of mGluR5 and glucose metabolism ([(18)F]FDG) were measured in bvFTD (n = 5) and cognitively normal (CN) subjects (n = 10). [(11)C]ABP688 binding potential maps (BPND) were calculated using the cerebellum as a reference region, with [(18)F]FDG standardized uptake ratio maps (SUVR) normalized to the pons. Grey matter (GM) concentrations were determined using VBM. Voxel-based group differences were obtained using RMINC. BvFTD patients showed widespread decrements in [(11)C]ABP688 BPND throughout frontal, temporal and subcortical areas. These areas were likewise characterized by significant hypometabolism and GM loss, with overlap between reduced [(11)C]ABP688 BPND and hypometabolism superior to that for GM atrophy. Several regions were characterized only by decreased binding of [(11)C]ABP688. The present findings represent the first in vivo report of decreased availability of mGluR5 in bvFTD. This study suggests that glutamate excitotoxicity may play a role in the pathogenesis of bvFTD and that [(11)C]ABP688 may prove a suitable marker of glutamatergic neurotransmission in vivo.

Fluoroscopy-free recrossing of the interatrial septum during left atrial ablation procedures

AIM

The purpose of this is to evaluate the safety and feasibility of recrossing the interatrial septum in case of inadvertent loss of or need for repeated left atrial access using a simple electroanatomical landmark without the use of fluoroscopy.

METHODS

Twenty-five consecutive patients undergoing pulmonary vein isolation (PVI) for paroxysmal (n = 12) or persistent (n = 13) atrial fibrillation ablation were included. All procedures were performed using an electroanatomical mapping system (Carto 3, Biosense Webster, Diamond Bar, USA). After fluoroscopy-guided double transseptal puncture and fast anatomical mapping of the left atrium, a reconstruction of the transseptal access was created by retracting the mapping catheter into the sheath to the level of the inferior vena cava. After completing the left sided ablation, both sheaths and catheters were withdrawn to the inferior vena cava. Recrossing was then attempted by fellows (EF) and experienced operators (EO) using the reconstruction of the transseptal access in a standard right anterior oblique (RAO) and left anterior oblique (LAO) projection without the use of fluoroscopy.

RESULTS

Using the described technique, EP fellows and experienced operators could recross the interatrial septum without fluoroscopy in all patients. Median time needed for recrossing was 14 s (interquartile range (IQR) 7-20). Median recrossing times did not differ significantly between EF and EO (14 (IQR 8-26.5 s) versus 12 (IQR 6.5-17.5 s), p = 0.26). In five (20 %) procedures, recrossing was necessary during the procedure after intermittent mapping of the right atrium or inadvertent catheter dislodgment.

CONCLUSION

Adding a simple and fast anatomical reconstruction of the transseptal access to the standard left atrial mapping procedure allows for easy and fluoroscopy-free recrossing of the interatrial septum during atrial fibrillation ablation and further reduces radiation exposure.

Canadian Cardiovascular Society guidelines on the use of cardiac resynchronization therapy: implementation

Recent studies have provided the impetus to update the recommendations for cardiac resynchronization therapy (CRT). This article provides guidance on the implementation of CRT and is intended to serve as a framework for the implementation of CRT within the Canadian health care system and beyond. These guidelines were developed through a critical evaluation of the existing literature, and expert consensus. The panel unanimously adopted each recommendation. The 9 recommendations relate to patient selection in the presence of comorbidities, delivery and optimization of CRT, and resources required to deliver this therapy. The strength of evidence was weighed, taking full consideration of any risk of bias, and any imprecision, inconsistency, and indirectness of the available data. The strength of each recommendation and the quality of evidence were adjudicated. Trade-offs between desirable and undesirable consequences of alternative management strategies were considered, as were values, preferences, and resource availability. These guidelines were externally reviewed by experts, modified based on those reviews, and will be updated as new knowledge is acquired.