Patient exposure to X-rays during coronary angiography and percutaneous transluminal coronary intervention: Results of a multicenter national survey

INCREASED EXPOSURE TO X-RAYS DURING CORONARY ANGIOGRAPHY AND PERCUTANEOUS CORONARY INTERVENTIONS ASSOCIATED WITH FRACTIONAL FLOW RESERVE MEASUREMENT AND ENDOCORONARY IMAGING TECHNIQUES

Growing use of fractional flow reserve (FFR) and intracoronary imaging techniques by optical coherence tomography or intravascular ultrasound has raised concerns about additional exposure during coronary angiography and percutaneous coronary interventions (PCIs). Using data from the prospective CRAC-France PCI Prospective Multicentre registry, we sought to evaluate the effect of these new techniques on the radiation dose to patients undergoing coronary procedures. Data on Kerma Area Product (PKA), total air kerma (KAr) and fluoroscopy time from 42 182 coronary procedures were retrospectively compared, using multivariable linear regression, according to whether they included FFR and intracoronary imaging. In coronary angiography, FFR was associated with longer fluoroscopy time and higher PKA (21.0 vs. 18.9 Gy.cm2) and KAr (372 vs. 299 mGy) (all p < 0.001). Intracoronary imaging was associated with longer fluoroscopy time, higher contrast volume (both p < 0.001), lower PKA (18.3 vs. 19.0 Gy.cm2, p = 0.02) and similar KAr. In PCI, FFR was associated with a moderate increase in KAr (682 vs. 626 mGy, p < 0.01) but not PKA (35.9 vs. 33.7 Gy.cm2, p = 0.34). For intracoronary imaging, there were no differences between groups, except for contrast volume. Increased patient exposure associated with FFR and intracoronary imaging is moderate in diagnostic coronary angiography and minimal or none in PCI, provided optimization techniques are used. It should not be a limitation on the use of these techniques given the important additional information they provide.

AN INTERVENTIONAL CARDIOLOGY INVESTIGATION: PATIENT EXPOSURE TO RADIATION AND INTER-OPERATOR VARIABILITY IN AN IRISH SETTING

AIM

To evaluate patient radiation exposure for Diagnostic Coronary Angiography (DCA) and Percutaneous Cardiac Intervention (PCI) performed by different operators.

METHODS AND RESULTS

Retrospective (n = 160) and prospective (n = 62) data for DCA (n = 179) and PCI (n = 43) examinations performed by interventional cardiologists (n = 3) using the same imaging equipment were reviewed. The operator with consistently low diagnostic reference levels (DRLs) was interviewed for their personal perceptions upon operator training. Retrospective Median [IQR] DAP was 18.8 [11.8-31.6] and 50.7 [35.3-85.6] Gy.cm2 for DCA and PCI, respectively. Prospective Median [IQR] DAP for DCA and PCI was 7.9 [5.2-10.6] and 15.9 [10.0-17.7] Gy.cm2, respectively. DRLs were within Irish and European DRLs; however, significant inter-operator variability (p < .001) was identified.

CONCLUSION

Radiation exposure in Interventional cardiology is highly operator dependent; further research is warranted in standardization of operator training with evolving technologies.

Does reducing radiation levels for procedures affect image quality and radiation to proceduralists? A double-blinded randomised study of two protocols

AIM

To evaluate the ultra-lose dose imaging protocol (ULDP), compared to the standard low-dose imaging protocol (LDP), which are used for haemodialysis access, in terms of radiation exposure and image quality.

MATERIAL AND METHODS

This was a single-centre, institutional review board-approved, prospective, double-blinded randomised controlled study to compare radiation exposure and image quality of the ULDP and LDP. Ten proceduralists, two radiographers, and 11 nurses were enrolled. Radiation exposure during 80 procedures (40 angioplasties and 40 thrombolysis) was recorded (direct radiation to patients from protocol report and scattered radiation to participants from the RaySafe i2 real-time dosimetry system). Baseline characteristics of procedure were recorded. Image quality was assessed subjectively using questionnaires based on the five-point Likert scale after each procedure.

RESULTS

Compared with LDP, the use of ULDP was associated with a significantly lower rate of radiation exposure to proceduralists, patients, and scrub nurses (0.506±0.430 versus 0.847±0.965 μSv/s, p=0.044; 0.571±1.284 versus 1.284±1.007 mGy/s, p<0.001; and 0.052±0.071 versus 0.141±0.185 μSv/s, p=0.005, respectively). No significant difference in image quality or duration of procedure was observed (all p values >0.05).

CONCLUSION

Compared with LDP, the use of ULDP was associated with a significantly lower rate of radiation exposure to proceduralists, patients, and scrub nurses without compromising the image quality or duration of procedure.

Radiation doses during cardiac catheterisation procedures in India: a multicentre study: Radiation dose study

AIMS

Established, evidence-based measures of radiation are required to minimise its hazards, while maintaining adequate image quality. The aim of this study is to evaluate radiation data and generate reference radiation levels for commonly performed coronary catheterisation procedures in India.

METHODS AND RESULTS

In this prospective, observational study, all procedures were performed in accordance with the established standards using Innova IGS 520/2100-IQ catheterisation laboratories. Demographic, procedural and radiation data were collected. Dose reference limits (DRL) were established as the 75th percentile of the total distribution. There were 2,906 coronary angiograms (CAG), 750 percutaneous coronary interventions (PCI) and 715 CAG+PCI. DRLs for dose area product were: 19.6 Gy·cm2 for CAG, 49.8 Gy·cm2 for PCI and 72.0 Gy·cm2 for CAG+PCI, respectively. Median cumulative air kerma levels were: 185 mGy for CAG, 533mGy for PCI, and 891 mGy for CAG+PCI. Male gender, higher BMI, combining CAG+PCI, fluoroscopy time, number of cine frames, and image acquisition settings were significant contributors to increased radiation dose.

CONCLUSIONS

This study established reference radiation dose levels for diagnostic and interventional coronary procedures in India, which were comparable to and in the lower range of international standards.

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.

Is trans-radial approach related to an increased risk of radiation exposure in patients who underwent diagnostic coronary angiography or percutaneous coronary intervention? (The SAKARYA study)

OBJECTIVE

It is still debatable whether diagnostic coronary angiography (CA) or percutaneous coronary interventions (PCIs) increase radiation exposure when performed via radial approach as compared to femoral approach. This question was investigated in this study by comparison of dose-area product (DAP), reference air kerma (RAK), and fluoroscopy time (FT) among radial and femoral approaches.

METHODS

All coronary procedures between November 2015 and November 2017 were assessed; and 4215 coronary procedures were enrolled in the study. Patients with bifurcation, chronic total occlusion, cardiogenic shock, or prior coronary artery bypass surgery were excluded. These 4215 procedures were evaluated for three different categories: diagnostic CA (Group I), PCI in patients with stable angina (Group II), and PCI in patients with ACS (Group III).

RESULTS

Age was significantly higher in the femoral arm of all groups. Among patients in the radial arm of Groups I and II, males were over-represented. Therefore, a multiple linear regression analysis with stepwise method was performed. After adjusting these clinical confounders, there was no significant difference with regard to DAP, RAK, and FT between femoral and radial access in Group I. In contrast, PCI via radial access was significantly associated with increased DAP, RAK, and FT in Groups II and III.

CONCLUSION

In spite of an increased experience with trans-radial approach, PCI of coronary lesions via radial route was associated with a relatively small but significant radiation exposure in our study. Compared to femoral access, diagnostic CA via radial access was not related to an increased radiation exposure.

Radiation exposure during cardiac device implantation: Lessons learned from a multicenter registry

BACKGROUND

Little data are available about radiation exposure during cardiac electrical device implantation, and no dose reference levels have been published. This multicenter, prospective, observational study assesses patient and staff radiation exposure during cardiac device implantations, and aims at defining dose reference levels.

METHODS

Patient demographic, procedural, and radiation data were obtained for 657 procedures from nine institutions. Physician and staff exposure were measured using real-time dosimeters worn beneath and above lead apron. Statistical analysis included fluoroscopy time (FT), dose-area product (DAP), and DAP adjusted for FT and body mass index.

RESULTS

Pacemakers and cardioverter defibrillators were implanted in 481 and 176 patients, respectively. Of these, 152 were treated with cardiac resynchronization therapy (CRT). Median FTs were 837s (interquartile range [IQR]: 480-1323), 117s (IQR: 69-209), and 101s (IQR: 58-162), and median DAPs were 1410 (IQR: 807-2601), 150 (IQR: 72-338), and 129 (IQR: 72-332) cGy.cm² for biventricular, dual chamber, and ventricular device implantation, respectively. Dose reference levels correspond to the third quartile values. During CRT, higher exposure was observed with four X-ray systems than with the two newer and customizable ones (adjusted DAP of 0.90 [IQR: 0.26-1.01] and 0.29 [IQR: 0.23-0.39], respectively; P < .001).

CONCLUSION

Based on real-life measurements, this multicenter registry provides dose reference levels and may help centers assess radiation exposure. Although biventricular device implantation was responsible for the highest radiation exposure, FT was meaningfully shortened compared to previously reported values. For a same FT, the use of new generators and custom settings has significantly reduced DAP.

Retrospective study of patients radiation dose during cardiac catheterization procedures

OBJECTIVE

Cardiac catheterization procedures provide tremendous benefits to modern healthcare and the benefit derived by the patient should far outweigh the radiation risk associated with a properly optimized procedure. With increasing utilization of such procedures, there is growing concern regarding the magnitude and variations of dose to patients associated with procedure complexity and techniques parameters. Therefore, this study investigated radiation dose to patients from six cardiac catheterization procedures at our facility and suggest possible initial dose values for benchmark for patient radiation dose from these procedures. This initial benchmark data will be used for clinical radiation dose management which is essential for assessing the impact of any quality improvement initiatives in the cardiac catheterization laboratory.

METHODS

We retrospectively analyzed the dose parameters of 1000 patients who underwent various cardiac catheterization procedures: left heart catheterization (LH), percutaneous coronary intervention (PCI), complex PCI, LH with complex PCI, LH with PCI and cardiac resynchronization therapy (CRT) pacemaker in our cardiac catheterization laboratories. Patient's clinical radiation dose data [kerma-area-product (KAP) and air-kerma at the interventional reference point (Ka,r)] and technique parameters (fluoroscopy time, tube potential, current, pulse width and number of cine images) along with demographic information (age, height and weight) were collected from the hospital's RIS (Synapse), Sensis/Syngo Dynamics and Siemens Sensis Stats Manager electronic database. Statistical analysis was performed with the IBM SPSS Modeler v. 18.1 software.

RESULTS

The overall patient median age was 67.0 (range: 26.0-97.0) years and the median body mass index (BMI) was 28.8 (range: 15.9-61.7) kg/m2 . The median KAP for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 44.4 (4.1-203.2), 80.2 (18.9-208.5), 83.7 (48.0-246.1), 113.8 (60.9-284.5), 91.7 (6.0-426.0) and 51.1 (7.0-175.9) Gy-cm2 . The median Ka,r for the LH, PCI, LH with complex PCI, complex PCI, LH with PCI and CRT-pacemaker procedures are 701.0 (35.3-3794.0), 1384.7 (291.7-4021.8), 1607.0 (883.5-4448.3), 2260.2 (867.4-5311.9), 1589.3 (100.2-7237.4) and 463.8 (67.7-1695.9) mGy respectively.

CONCLUSION

We have analyzed patient radiation doses from six commonly used procedures in our cardiac catheterization laboratories and suggested possible initial values for benchmark from these procedures for the fluoroscopy time, KAP and air-kerma at the interventional reference point based on our current practices. Our data compare well with published values reported in the literature by investigators who have also studied patient doses and established benchmark dose levels for their facilities. Procedure-specific benchmark dose data for various groups of patients can provide the motivation for monitoring practices to promote improvements in patient radiation dose optimization in the cardiac catheterization laboratories.

ADVANCES IN KNOWLEDGE

We have investigated local patients' radiation doses and established benchmark radiation data which are essential for assessing the impact of any quality improvement initiatives for radiation dose optimization.

Transcatheter Pulmonary Valve Replacement in Congenital Heart Disease

Patients with dysfunctional right ventricular outflow tracks comprise a large portion of patients with severe congenital heart disease. Transcatheter pulmonary valve replacement in patients with dysfunctional right ventricular outflow tracks is feasible, safe, and efficacious. This article reviews current transcatheter valve replacement technology for dysfunctional right ventricular outflow tract and pulmonary valvular disease and its applications to patients with congenital heart disease. Discussed are the approach and preprocedural planning, current options, and applications of transcatheter pulmonary valve therapy. Also considered are future directions in this field as the technologies begin to develop further.

Reduction of radiation exposure associated with renewal of the radiologic systems in coronary interventions

PURPOSE

Interventional coronary procedures are an important source of radiation. This study sought to evaluate the effect of the renewal of the radiologic system on patient exposure during diagnostic coronary angiography (DCA) and percutaneous coronary interventions (PCIs).

METHODS

DCA and PCIs were obtained from three centres, which renewed their radiologic systems during their participation in the multicentre prospective observational RAY'ACT-2 study. Data were analysed from the months before and after the radiologic system was changed. The primary outcomes were the dose reduction estimated by the kerma.area product (KAP in Gy·cm²) and the ratio of the KAP to fluoroscopy time (Gy·cm²·min^-1).

RESULTS

A total of 2148 patients underwent DCA (1575 before and 573 after the system change), and 1563 underwent PCI (1196 before and 367 after). A change in the radiologic system was associated with a KAP reduction of 43% for DCA (median [interquartile range]: 18.1Gy·cm² [10.2-34.0] versus 31.5 [19.0-49.0], P<0.0001), and 38% for PCI (42.2Gy·cm² [23.8-81.7] versus 70.1 [42.0-109.0], P<0.0001). Fluoroscopy time did not vary significantly, and the ratio KAP to fluoroscopy time significantly decreased by 54%. The dose reduction was homogeneous between the three centres and between different manufacturer's systems.

CONCLUSIONS

In this multicentre study, the renewal of the radiologic system was associated with a highly significant 40%-50% reduction in radiation dose, irrespective of the manufacturer. A close interaction between manufacturers and operators is needed to optimise the use of new equipment and the effectiveness of radiation reduction tools and techniques.

Impact of Allura Clarity Technology on Radiation Dose Exposure During Left Atrial Appendage Closure

BACKGROUND

To evaluate the impact of the Clarity IQ technology on reducing radiation risk in patients undergoing cardiac interventional radiology (IR) procedures.

MATERIAL/METHODS

Phantom studies were performed with two angiographic systems, FD10 Allura Xper and FD10 Allura Clarity. In the study, we performed left atrial appendage closure. Dosimetric measurements were performed with thermoluminescent dosimeters (TLD) placed inside a CIRS anthropomorphic phantom. Radiation risk was estimated based on the TLD readings and expressed as the dose absorbed by particular organs. The Mann-Whitney U test was carried out to test for significance of differences in the absorbed radiation doses between the techniques.

RESULTS

During left atrial appendage closure, the estimated dose absorbed by particular organs was lower in the case of the FD10 Allura Clarity system in comparison to the Allura Xper. In this procedure, dose reduction for particular organs ranged between 49-86%.

CONCLUSIONS

Application of the FD10 Allura Clarity system resulted in a significant dose reduction, thereby leading to a significant decrease in radiation risk for patients undergoing IR procedures.

Endovascular Creation of an Arteriovenous Fistula (endoAVF) for Hemodialysis Access: First Results

INTRODUCTION

Surgical creation of a radiocephalic fistula is the gold standard of vascular access for hemodialysis. Recently, an endovascular approach for upper arm fistula creation (endoAVF) has been developed, which may be an alternative to open surgery. We describe a case series of eight cases showing feasibility, early complications and outcome of this novel treatment option.

MATERIALS AND METHODS

Between July 2015 and February 2016, we created an endoAVF in eight patients. Indications for endoAVF were confirmed by a multidisciplinary vascular board upon the exclusion for Cimino fistula candidates. Patients were suitable for the procedure after a pre-therapeutic ultrasound showed adequate brachial and ulnar vessels and no ipsilateral central venous stenosis. Patient characteristics, technical success, total patient radiation dose, complication rates, time to maturation of endoAVF and clinical effectiveness at six months were assessed retrospectively.

RESULTS

Creation of endoAVF using the everlinQ endoAVF system (TVA Medical Inc., Austin, TX, USA) was successful in all eight cases. There were one minor intraprocedural complication and no postoperative complications. Median time to endoAVF maturation was 63 days (range 26-137 days). One patient was lost to follow-up after the first monitoring visit. In the remaining seven patients, hemodialysis was started without problems. Patency after 6 months was 100%.

DISCUSSION

The endoAVF demonstrated to be feasible and safe for the creation of arteriovenous fistula suitable for hemodialysis access. Further studies with more patients and longer follow-up periods are needed to assess long-term outcomes and comparability to surgical dialysis access creation.

Time-Course Reduction in Patient Exposure to Radiation From Coronary Interventional Procedures

Background—

The frequency of complex percutaneous coronary interventions (PCIs) has increased in the last few years, with a growing concern on the radiation dose received by the patients. Multicenter data from large unselected populations on patients’ radiation doses during coronary angiography (CA) and PCI and temporal trends are lacking. This study sought to evaluate the temporal trends in patients’ exposure to radiation from CA and PCI.

Methods and Results—

Data were taken from the CARDIO-ARSIF registry that prospectively collects data on all CAs and PCIs performed in the 36 catheterization laboratories in the Greater Paris Area, the most populated regions in France with about 12 million inhabitants. Kerma area product and Fluoroscopy time from 152 684 consecutive CAs and 103 177 PCIs performed between 2009 and 2013 were analyzed. A continuous trend for a decrease in median [interquartile range] Kerma area product was observed, from 33 [19–55] Gy cm 2 in 2009 to 27 [16–44] Gy cm 2 in 2013 for CA ( P <0.0001), and from 73 [41–125] to 55 [31–91] Gy cm 2 for PCI ( P <0.0001). Time-course differences in Kerma area product remained highly significant after adjustment on Fluoroscopy time, PCI procedure complexity, change of x-ray equipment, and other patient- and procedure-related covariates.

Conclusions—

In a large patient population, a steady temporal decrease in patient radiation exposure during CA and PCI was noted between 2009 and 2013. Kerma area product reduction was consistent in all types of procedure and was independent of patient-related factors and PCI procedure complexity.

Radiation Doses to Patients in Interventional Coronary Procedures-Estimation of Updated National Reference Levels by Dose Audit

The objective of this study was to estimate the French national updated reference levels (RLs) for coronary angiography (CA) and percutaneous coronary intervention (PCI) by a dose audit from a large data set of unselected procedures and in standard-sized patients. Kerma-area product (PKA), air kerma at interventional point (Ka,r), fluoroscopy time (FT), and the number of registered frames (NFs) and runs (NRs) were collected from 51 229 CAs and 42 222 PCIs performed over a 12-month period at 61 French hospitals. RLs estimated by the 75th percentile in CAs and PCIs performed in unselected patients were 36 and 78 Gy.cm² for PKA, 498 and 1285 mGy for Ka,r, 6 and 15 min for FT, and 566 and 960 for NF, respectively. These values were consistent with the RLs calculated in standard-sized patients. The large difference in dose between sexes leads us to propose specific RLs in males and females. The results suggest a trend for a time-course reduction in RLs for interventional coronary procedures.

Assessment of Patient's Peak Skin Dose Using Gafchromic Films During Interventional Cardiology Procedures: Routine Experience Feedback

To assess the interest of Gafchromic films in detection of patient's peak skin dose (PSD) in interventional cardiology. A prospective study of 112 patients was conducted (July-December 2015). Three diagnostic and therapeutic procedures were evaluated: coronary angiography (CA), coronary angiography and coronary angioplasty for one or two vessels disease (CA-PTCA) and coronary angioplasty of complex chronic total occlusion (CTO). Dosimetric indicators (DIs) were collected and PSD were measured with Gafchromic films. Dose distribution was evaluated within 10 'Thorax Body-zone' defined by the system. Correlations between PSD and DI or dose distribution were computed. Delivered dose increased in complex procedures. The PSD were 0.121 ± 0.063 Gy for CA, 0.256 ± 0.142 Gy for CA-PTCA and 1.116 ± 0.721 Gy for CTO. High correlations were observed for PSD and DI as well for dose distribution within the 'Thorax Body-zone'. Film dosimetry is suggested for CTO procedures since the threshold of 2 Gy for skin injuries is likely to be exceeded.

Analysis of a Low Dose Protocol to Reduce Patient Radiation Exposure During Percutaneous Coronary Interventions

The cardiac catheterization laboratory is an important source of radiation for patients and operators and it is good practice to limit exposure as much as possible. The purpose of this study was to evaluate the effectiveness and impact of a radiological low dose protocol (LDP) in terms of reduction in patient radiation exposure during percutaneous coronary interventions (PCIs). From November 2014 to October 2015, 906 consecutive patients who underwent PCI were evaluated. Of these, 571 patients (63%) were treated with the standard dose protocol (SDP) of 15 frames per second for cine acquisition and standard settings for fluoroscopy, and 335 patients (37%) with the LDP of 7.5 frames per second for cine acquisition and low-dose settings for fluoroscopy. In the LDP group, we observed a significant reduction of kerma area product (53.3 LDP vs 115 SDP Gycm², p <0.0001) and air kerma at interventional reference point (0.79 LDP vs 1.976 SDP Gy, p <0.0001). Marked differences were observed regarding the exceeding of International Commission on Radiological Protection and National Council on Radiation Protection and Measurements' air kerma at interventional reference point trigger level (cutoff for potential skin injuries), which were significantly lower in the LDP group (1.8% vs 7.2%, p <0.0001). Such difference was more relevant in complex PCI. In conclusion, the implementation of LDP allowed a marked reduction in patient dosimetric parameters for PCI and significantly reduced the risk of exceeding the International Commission on Radiological Protection/National Council on Radiation Protection and Measurements trigger levels for potential skin injuries.

Coronary Procedures After TAVI With the Self-Expanding Aortic Bioprosthesis Medtronic CoreValve™, Not an Easy Matter

OBJECTIVES

To evaluate the feasibility of coronary procedures after transcatheter aortic valve implantation (TAVI) with the CoreValve™ device.

BACKGROUND

Due to its design, CoreValve™ prosthesis may interfere with coronary procedures. Data on this issue are sparse.

METHODS

Between 2007 and 2015, 550 patients underwent CoreValve™ TAVI in our hospital. Among them, 16 underwent coronary angiogram after TAVI and were included in our retrospective study. For each patient, we compared the characteristics of coronary angiograms performed before and after TAVI.

RESULTS

Coronary angiogram was deemed successful in 9 patients. The mean number of different catheters used in attempts to cannulate the coronary arteries was 3.6 ± 1.4 and the rate of selective intubation was low. Fluoroscopy time (13.2 ± 5.8 vs. 7.2 ± 4.6 min, P = 0.003), dose area product (5,347 ± 4,919 vs. 3,433 ± 3,420 cGy/m² , P = 0.004), and contrast volume (157.7 ± 69.6 vs. 108.3 ± 42.6 mL, P = 0.006) were more important in coronary angiograms performed after CoreValve™ implantation. Percutaneous coronary intervention was successfully performed in 6 out of 7 patients who required it.

CONCLUSION

Coronary procedures after CoreValve™ TAVI are feasible, but challenging. This problem is currently rare but will be more common as the indications of TAVI are expanded to younger patients with longer life expectancies. Recommendations for post-TAVI coronary procedures are needed, particularly for centers unfamiliar with the management of post-TAVI patients.

Decreased patient exposure to ionizing radiation during interventional rheumatology procedures after optimization of protection

OBJECTIVES

To decrease radiation exposure of patients undergoing interventional rheumatology procedures, without adversely affecting quality of care.

METHODS

The radiation dose received, assessed by the dose-area product (DAP), was measured during 283 intraarticular injections performed under fluoroscopic guidance between May and July 2013. Then, three steps were taken to decrease patients' radiation exposure: a copper filter was added, the anti-scatter grid was removed, and exposure cell sensitivity was set at the highest value. DAP was measured during 158 intraarticular injections performed in 2014 with these measures in place.

RESULTS

Mean DAP before optimization was 175μGray·m² during facet joint injections (n=4) and 43μGray·m² during hip injections but was less than 20μGray·m² for injections into the shoulders (15.7μGray·m²), ankles (7.7μGray·m²), wrists (3.7μGray·m²), and fingers (3.3μGray·m²). After optimization, DAP decreased markedly for all injection sites, by 52% (shoulders) to 87% (facet joints, 22.7μGray·m²). Decreases occurred at all three steps of the procedure, i.e., patient installation, injection, and last image hold. Exposure during facet joint injections varied from 84 (54.5-108.5) μGray·m² when body mass index (BMI) was <25kg/m² to 228.9 (161.3-340.4)μGray·m² when BMI was>30kg/m².

CONCLUSION

Simple technical changes translate into large decreases in patient radiation exposure during fluoroscopically-guided injections, particularly at the facet joints and in obese patients.

Comparison of the patient radiation exposure during coronary angiography and angioplasty procedures using trans-radial and trans-femoral access

INTRODUCTION

Cardiac catheterization procedure through the trans-radial access (TRA) have shown many clinical advantages over the trans-femoral (TFA), but despite its advantages, there are serious concerns regarding higher possible radiation dose for the patients and operators in TRA. This study was planned to compare the patients' radiation dose associated with TRA and TFA during coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Of 700 candidates for angiography, 326 patients were entered the study. All the procedures were carried out by one interventional cardiologist employing the same angiography unit in Aalinasab hospital and the patients' dose area product (DAP), air kerma (AK), fluoroscopy time (FT) and cine film time (CFT) were then determined in both access groups (TRA,TFA) in CA, PTCA and CA+PTCA procedures.

RESULTS

The mean FT, CFT and AK values in both TRA & TFA groups were the same in all procedures (P>0.05). The mean DAP in CA+PTCA procedures was 6704.01±3243.23 µGym(2) in femoral access compare with 5647.46±2797.74 µGym(2) in radial access, which were significantly less than that in TFA with P= 0.02.

CONCLUSION

On the basis of the results obtained in this study, no differences were found in patients' radiation dose in both access groups, therefore with regard to comparatively more clinical advantages associated with the Trans-radial access technique it might be a good substitute for Trans-femoral access.

Radiation exposure in relation to the arterial access site used for diagnostic coronary angiography and percutaneous coronary intervention: a systematic review and meta-analysis

BACKGROUND

Transradial access for cardiac catheterisation results in lower bleeding and vascular complications than the traditional transfemoral access route. However, the increased radiation exposure potentially associated with transradial access is a possible drawback of this method. Whether transradial access is associated with a clinically significant increase in radiation exposure that outweighs its benefits is unclear. Our aim was therefore to compare radiation exposure between transradial access and transfemoral access for diagnostic coronary angiograms and percutaneous coronary interventions (PCI).

METHODS

We did a systematic review and meta-analysis of the scientific literature by searching the PubMed, Embase, and Cochrane Library databases with relevant terms, and cross-referencing relevant articles for randomised controlled trials (RCTs) that compared radiation parameters in relation to access site, published from Jan 1, 1989, to June 3, 2014. Three investigators independently sorted the potentially relevant studies, and two others extracted data. We focused on the primary radiation outcomes of fluoroscopy time and kerma-area product, and used meta-regression to assess the changes over time. Secondary outcomes were operator radiation exposure and procedural time. We used both fixed-effects and random-effects models with inverse variance weighting for the main analyses, and we did confirmatory analyses for observational studies.

FINDINGS

Of 1252 records identified, we obtained data from 24 published RCTs for 19 328 patients. Our primary analyses showed that transradial access was associated with a small but significant increase in fluoroscopy time for diagnostic coronary angiograms (weighted mean difference [WMD], fixed effect: 1·04 min, 95% CI 0·84-1·24; p<0·0001) and PCI (1·15 min, 95% CI 0·96-1·33; p<0·0001), compared with transfemoral access. Transradial access was also associated with higher kerma-area product for diagnostic coronary angiograms (WMD, fixed effect: 1·72 Gy·cm(2), 95% CI -0·10 to 3·55; p=0·06), and significantly higher kerma-area product for PCI (0·55 Gy·cm(2), 95% CI 0·08-1·02; p=0·02). Mean operator radiation doses for PCI with basic protection were 107 μSv (SD 110) with transradial access and 74 μSv (68) with transfemoral access; with supplementary protection, the doses decreased to 21 μSv (17) with transradial access and 46 μSv (9) with transfemoral. Meta-regression analysis showed that the overall difference in fluoroscopy time between the two procedures has decreased significantly by 75% over the past 20 years from 2 min in 1996 to about 30 s in 2014 (p<0·0001). In observational studies, differences and effect sizes remained consistent with RCTs.

INTERPRETATION

Transradial access was associated with a small but significant increase in radiation exposure in both diagnostic and interventional procedures compared with transfemoral access. Since differences in radiation exposure narrow over time, the clinical significance of this small increase is uncertain and is unlikely to outweigh the clinical benefits of transradial access.

FUNDING

None.

Assessment of Local Dose Reference Values for Recanalization of Chronic Total Occlusions and Other Occlusions in a High-Volume Catheterization Center

The increasing number and complexity of these procedures have led to a higher number of patients at risk for tissue reactions like skin injuries. Monitoring of their dose indicators is essential in recognizing these patients. The aim of this work was to determine local diagnostic reference levels (DRLs) for recanalization of chronic total occlusion (CTO) and other occlusions procedures. All data from patients who underwent cardiac procedures were reviewed and classified according to their complexity. Dose indicators such as fluoroscopy time (FT), dose area product (DAP), and air kerma at patient entrance reference point (AKr) were recorded. Correlations with patient's body mass index, operators, procedure strategy, and complexity were studied. For CTO, the mean DAP, AKr, and FT were 252 ± 234 Gycm(2), 3,985 ± 3,579 mGy, and 47 ± 36 minutes, respectively. To better reflect the non-Gaussian distribution of data, the median and the 75th percentile values were also reported: median DAP, 172 Gycm(2); 75th percentile DAP, 350 Gycm(2); median AKr, 2,714 mGy; and 75th percentile AKr, 5,921 mGy. A tentative new set of values were suggested to take into account the complexity difference in recanalization of total occlusions according to their antegrade or retrograde approach. These approach-specific DRLs for total occlusions were mean DAP (120 ± 114 Gycm(2)), mean AKr (1,789 ± 1,933 mGy), and mean FT (22 ± 18 minutes) for antegrade approach and mean DAP (459 ± 304 Gycm(2)), mean AKr (6,881 ± 4,243 mGy), and mean FT (82 ± 40 minutes) for retrograde approach. The other significant values were median DAP (84 Gycm(2)), 75th percentile DAP (147 Gycm(2)), median AKr (1,160 mGy), and 75th percentile AKr (2,176 mGy) for antegrade approach and median DAP (422 Gycm(2)), 75th percentile DAP (552 Gycm(2)), median AKr (6,295 mGy), and 75th percentile AKr (8,064 mGy) for retrograde approach. In conclusion, a set of local DRL values from a large center were assessed. DRLs were provided for antegrade and retrograde approaches, reflecting the difference in difficulty from these 2 kinds of CTOs. The wide dose estimator values variations were explained through procedure complexity. The values obtained for the other more classic percutaneous coronary interventions were comparable with those found in the literature.

Long-term strategies support autonomy in radiation safety in invasive cardiology

BACKGROUND AND PURPOSE

Despite comprehensive radiation safety programs, radiation exposure in invasive cardiology remains considerable. According to the 2013 German Registry, median in-hospital dose area products (DAP) amount to 19.8Gycm(2) for invasive coronary angiography (CA). We analyzed long-term radiation-reducing strategies for an experienced interventionalist from 1997 to 2012, for the target intervention of CA.

METHODS

Among representative cohorts, we evaluated iterative alterations in collimation, time on beam, pulse rates, detector entrance doses, and angulations on the basis of DAP, radiographic DAP(R) and fluoroscopic DAP(F), the respective times on beam, and the number of frames and runs.

RESULTS

Patients' median overall DAP decreased from 33.8Gycm(2) at baseline to 2.4 and 0.6Gycm(2) for CA in conventional (C) and electrocardiogram-gated (E) modes - one diastolic radiographic frame per heartbeat at 77% of the RR interval. Further median dose parameters for CA at baseline and finally in C/E mode were as follows: effective dose (6.76-0.48/0.13mSv), radiography time (43.8-12.9/21.7s), frames (548-105/25), frames/run (41.3-14.4/3.4), DAP(R)/frame (42.6-16.6/12.6mGycm(2)), DAP(R)/s (532-130/13.8mGycm(2)/s), fluoroscopy time (195-120/119s), DAP(F)/pulse (2.0-1.1/0.8mGycm(2)), and DAP(F)/s (48.9-4.4/3.1mGycm(2)/s).

CONCLUSIONS

Our data highlight the efficacy of various radiation-reducing strategies by autonomous control and iterative training in radiation safety toward submillisievert levels for CA, and define realizable benchmarks for comparison with the performance data of any individual.

Novel X-ray imaging technology enables significant patient dose reduction in interventional cardiology while maintaining diagnostic image quality

Objectives

The purpose of this study was to quantify the reduction in patient radiation dose during coronary angiography (CA) by a new X‐ray technology, and to assess its impact on diagnostic image quality.

Background

Recently, a novel X‐ray imaging technology has become available for interventional cardiology, using advanced image processing and an optimized acquisition chain for radiation dose reduction.

Methods

70 adult patients were randomly assigned to a reference X‐ray system or the novel X‐ray system. Patient demographics were registered and exposure parameters were recorded for each radiation event. Clinical image quality was assessed for both patient groups.

Results

With the same angiographic technique and a comparable patient population, the new imaging technology was associated with a 75% reduction in total kerma‐area product (KAP) value (decrease from 47 Gycm² to 12 Gycm², P < 0.001). Clinical image quality showed an equivalent detail and contrast for both imaging systems. On the other hand, the subjective appreciation of noise was more apparent in images of the new image processing system, acquired at lower doses, compared to the reference system. However, the higher noise content did not affect the overall image quality score, which was adequate for diagnosis in both systems.

Conclusions

For the first time, we present a new X‐ray imaging technology, combining advanced noise reduction algorithms and an optimized acquisition chain, which reduces patient radiation dose in CA drastically (75%), while maintaining diagnostic image quality. Use of this technology may further improve the radiation safety of cardiac angiography and interventions. © 2015 Wiley Periodicals, Inc.

Multicenter long-term validation of a minicourse in radiation-reducing techniques in the catheterization laboratory

Patient radiation exposure in invasive cardiology is considerable. We aimed to investigate, in a multicenter field study, the long-term efficacy of an educational 90-minute workshop in cardiac invasive techniques with reduced irradiation. Before and at a median period of 2.5 months and 2.0 years after the minicourse (periods I, II, and III, respectively) at 5 German cardiac centers, 18 interventionalists documented various radiation parameters for 10 coronary angiographies. The median patient dose area product (DAP) for periods I, II, and III amounted to 26.6, 12.2, and 9.6 Gy × cm(2), respectively. The short-term and long-term effects were related to shorter median fluoroscopy times (180, 138, and 114 seconds), fewer radiographic frames (745, 553, and 417) because of fewer (11, 11, and 10) and shorter (64, 52, and 44 frames/run) runs, consistent collimation, and restriction to an adequate image quality; both radiographic DAP/frame (27.7, 17.3, and 18.4 mGy × cm(2)) and fluoroscopic DAP/second (26.6, 12.9, and 14.9 mGy × cm(2)) decreased significantly. Multivariate analysis over time indicated increasing efficacy of the minicourse itself (-55% and -64%) and minor influence of interventionist experience (-4% and -3% per 1,000 coronary angiographies, performed lifelong until the minicourse and until period III). In conclusion, autonomous self-surveillance of various dose parameters and feedback on individual radiation safety efforts supported the efficacy of a 90-minute course program toward long-lasting and ongoing patient dose reduction.

Substantial radiation reduction in pediatric and adult congenital heart disease interventions with a novel X-ray imaging technology

Background

Pediatric catheterization exposes patients to varying radiation doses. Concerns over the effects of X-ray radiation dose on the patient population have increased in recent years. This study aims at quantifying the patient radiation dose reduction after the introduction of an X-ray imaging technology using advanced real time image noise reduction algorithms and optimized acquisition chain for fluoroscopy and exposure in a pediatric and adult population with congenital heart disease.

Methods

Patient and radiation dose data was retrospectively collected (July 2012–February 2013) for 338 consecutive patients treated with a system using state of the art image processing and reference acquisition chain (referred as “reference system”). The same data was collected (March–October 2013) for 329 consecutive patients treated with the new imaging technology (Philips AlluraClarity, referred as “new system”). Patients were divided into three weight groups: A) below 10 kg, B) 10–40 kg, and C) over 40 kg. Radiation dose was quantified using dose area product (DAP), while procedure complexity using fluoroscopy time, procedure duration and volume of contrast medium.

Results

The new system provides significant patient dose reduction compared to the reference system. Median DAP values were reduced in group A) from 140.6 cGy·cm² to 60.7 cGy·cm², in group B) from 700.0 cGy·cm² to 202.2 cGy·cm² and in group C) from 4490.4 cGy·cm² to 1979.8 cGy·cm² with reduction of 57%, 71% and 56% respectively (p < 0.0001 for all groups).

Conclusions

Despite no other changes in procedural approach, the novel X-ray imaging technology provided substantial radiation dose reduction of 56% or higher.

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x-ray radiation dose in pediatric patients is of specific concern as congenital heart disease is more often treated by interventional measures.

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the effect of advanced real time image noise reduction algorithms and optimized acquisition chain for fluoroscopy and exposure was studied.

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A state of the art image processing and reference acquisition chain was compared to the new imaging technology in 338 vs 329 consecutive patients.

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Patients were divided into three weight groups: A) below 10 kg, B) 10-40 kg, and C) over 40 kg according to clinical practice and procedure complexity.

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the novel X-ray imaging technology provided substantial radiation dose reduction of 56% or higher.