Institutional Variability in Patient Radiation Doses ≥5 Gy During Percutaneous Coronary Intervention

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.

Patient follow-up for possible radiation injury from fluoroscopically-guided interventions: Need to consider high cumulative exposure from multiple procedures

PURPOSE

Patient skin dose from interventional fluoroscopy procedures may exceed the threshold of tissue injuries and established guidelines recommend patient follow-up for air kerma at reference point (K_a,r) ≥ 5 Gy for individual procedures. Patients may undergo multiple procedures and skin injuries may be possible by cumulative exposure, even when individually insufficient to cause injury. This study sought to quantify the frequency of patients whose individual procedure doses are below 5 Gy but whose cumulative K_a,r is ≥ 5 Gy.

METHODS

This retrospective study analyzed 37,917 consecutive procedures in interventional radiology and vascular surgery at a tertiary-care hospital between January 2016 and June 2021. Radiation dosage was retrieved from the fluoroscopy acquisition systems. For a patient receiving multiple procedures, but each with K_a,r < 5 Gy, cumulative K_a,r within 2, 7, 14, 30, 183, and 365 days was assessed.

RESULTS

Nearly 1/3rd (37.4 %) patients underwent multiple procedures. With individual procedures of K_a,r < 5 Gy exclusively, 1.9, 4.4, and 5.6 in 1000 patients received cumulative K_a,r of 5-14.1 Gy from the procedures within 30, 183, and 365 days, respectively. From the procedures within 14 days, 1.3 in 1000 patients received cumulative K_a,r of 5-11.4 Gy; and from those within 7 days, 0.87 in 1000 patients received 5-9.1 Gy. In comparison, 4.3 in 1000 patients received K_a,r of 5-12 Gy from a single procedure.

CONCLUSIONS

In the absence of guidelines on patient follow-up for multiple procedures, our study may provide good material for setting up such guidelines.

Rates of Intracoronary Imaging Optimization in Contemporary Percutaneous Coronary Intervention: A Report From the BMC2 Registry

BACKGROUND

Intracoronary imaging (ICI) during percutaneous coronary intervention (PCI) improves outcomes, yet hospital- and physician-level variabilities in ICI and its impact on ICI use in contemporary PCI remain unknown. This study was performed to evaluate hospital- and physician-level use of ICI to optimize PCI.

METHODS

Using data from a large statewide registry, patients undergoing PCI between July 2019 and March 2021 were studied. The primary measure of interest was ICI (intravascular ultrasound or optical coherence tomography) optimization during PCI. A fitted hierarchical Bayesian model identified variables independently associated with ICI optimization. The performing hospital and physician were included as random effects in the model.

RESULTS

Among 48 872 PCIs, ICI optimization was performed in 8094 (16.6%). Median [interquartile range] hospital- and physician-level frequencies of ICI were 8.8% [3.1%, 16.0%] and 6.1% [1.1%, 25.0%], respectively. Bayesian modeling identified left main PCI (adjusted odds ratio [aOR], 4.41; 95% credible interval [3.82, 5.10]), proximal left anterior descending artery PCI (aOR, 2.28 [2.00, 2.59]), PCI for in-stent restenosis (aOR, 1.55 [1.40, 1.72]), and surgical consult prior to PCI (aOR, 1.21 [1.07, 1.37]) as independent predictors of ICI optimization. The hospital-level median odds ratio, an estimate of the contribution of inter-hospital variability in odds of ICI use, was 3.48 (2.64, 5.04). Physician-level median odds ratio was 3.81 (3.33, 4.45).

CONCLUSIONS

Substantial hospital- and physician-level variation in ICI was observed. Except for performance of left main PCI, the hospital and physician performing the PCI were more strongly associated with ICI optimization than any patient or procedural factors.

Trends and predictors of radiation exposure in percutaneous coronary intervention: the PROTECTION VIII study

BACKGROUND

Percutaneous coronary intervention (PCI) is indispensable in cardiology; however, exposure to potentially harmful ionising radiation remains a concern.

AIMS

This study was designed to assess the PCI-related radiation dose over the last decade and to identify predictors of increased dose exposure.

METHODS

The PROcedural radiaTion dose Exposure in percutaneous Coronary intervenTION (PROTECTION VIII) study included all PCIs reported to a German quality assurance programme between 2008 and 2018. Dose area product (DAP) and radiation time were analysed. Effective dose (ED) was estimated (ED=DAP*k; conversion coefficient k=0.0022 mSv/cGy*cm²). Multivariate linear regression analysis was used to identify predictors associated with a clinically relevant increase of radiation dose (ED ≥1 mSv).

RESULTS

We enrolled 3,704,986 patients undergoing PCI (median age 70 years, 30% female). Indications were chronic coronary syndrome (37.5%), unstable angina pectoris and non-ST-segment elevation myocardial infarction (non-STEMI; 33.2%) and STEMI (18.5%). Median DAP was 4,203 (interquartile range [IQR] 2,313-7,300) cGy*cm, ED was 9.2 mSv and median radiation time was 9.2 (IQR 5.8-15.0) min. Within the 10-year period, radiation exposure was reduced by 36% (p<0.001) and resulted in a median DAP of 3,070 cGy*cm (ED 6.8 mSv) in 2018. A significant 5.3-fold variability of median DAP was observed between catheterisation laboratories (p<0.001). We identified patient-related (gender, coronary artery bypass graft surgery, heart failure) and procedure-related (coronary occlusion PCI, ostial lesion PCI, left main PCI, multivessel PCI) predictors of increased radiation dose (all p<0.001).

CONCLUSIONS

This radiation dose survey demonstrates a considerable reduction of PCI radiation exposure during the last decade. However, large variability between catheterisation laboratories underlines the need for further radiation dose reduction.

A novel catheterization laboratory radiation shielding system: Results of pre-clinical testing

BACKGROUND

This pre-clinical study evaluated the efficacy of a novel shielding system to reduce scatter radiation in the cardiac catheterization laboratory.

METHODS

Using a scatter radiation phantom in a standard cardiac catheterization laboratory, a radiation physicist recorded radiation measurements at 20 reference points on the operator side of the table. Measurements were made with fluoroscopy and cine with the C-arm in the posterior-anterior (PA) and 40 degrees left anterior oblique (LAO) orientations. Scatter radiation doses were compared with and without use of the shielding system.

RESULTS

Use of the shielding system was associated with >94.2% reduction in scatter radiation across all reference points in the PA and LAO projections with fluoroscopy and cine. With the shielding system, dose reductions at the location of the primary operator ranged from 97.8% to 99.8%. At locations of maximum scatter radiation, use of the shielding system resulted in dose reductions ranging from 97.8% to 99.8% with fluoroscopy and from 97.9% to 99.8% with cine.

CONCLUSIONS

In this pre-clinical study, a novel radiation shielding system was observed to dramatically reduce scatter radiation doses. Based on these results, clinical testing is warranted to determine whether the shielding system will enable operators and staff to perform interventional procedures with less radiation exposure that may obviate the need to wear standard lead apparel.

INDEXING WORDS

Radiation safety; occupational health; occupational hazard.

Comparative Safety of Bioabsorbable Polymer Everolimus-Eluting, Durable Polymer Everolimus-Eluting, and Durable Polymer Zotarolimus-Eluting Stents in Contemporary Clinical Practice

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