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WASHINGTON -- The radial approach during percutaneous coronary procedures for acute coronary syndromes (ACS) was linked to a significantly higher operator radiation dose versus femoral access, researchers reported here.
Among 18 operators who performed over 700 procedures, the operator equivalent dose at the thorax was significantly higher with radial than femoral access at 77 µSv (IQR:40-112) compared with 41 µSv (IQR:23-59, P=0.02), according to of the Sandro Pertini Hospital in Rome, and colleagues.
Action Points
- Note that this observational study found that a radial approach to percutaneous coronary intervention was associated with higher levels of operator and patient radiation dose.
- This persisted even when accounting for total fluoroscopy time.
After normalization of operator radiation dose by fluoroscopy time or dose area product (DAP), the difference remained significant, they reported at the American College of Cardiology annual meeting and in the.
Radiation dose at wrist or head did not differ between radial and femoral access, the authors added.
While the group did find that patients also had greater exposure with the radial approach, Sciahbasi told 麻豆传媒 that "the amount of excess radiation a patient receives for a single operation would increase his lifetime risk of a radiation-induced malignancy by one in 35,000."
Instead, his group focused on radiation exposure to operators as they could be exposed to excess radiation several times a day and over many years.
The use of radial access rather than femoral for coronary angiography and percutaneous coronary intervention has been associated to lower risk of bleeding, vascular complications, and greater survival in patients with ACS undergoing invasive management. But concerns have been raised over the increased risk of radiation exposure for both patients and operators with radial instead of femoral access, the authors explained.
In the , they randomized 8,404 patients, with or without ST-segment elevation ACS, to radial or femoral access for coronary angiography and percutaneous intervention. For the RAD-MATRIX substudy, they collected fluoroscopy time and DAP. Operators wore a thorax (primary endpoint), wrist and head (secondary endpoints) lithium fluoride thermoluminescent dosimeter.
The authors said they established that 13 or more operators, and at least 13 patients per access site, were needed to establish noninferiority of radial versus femoral access.
They reported that for the 18 operators who performed 777 procedures in 767 patients, the noninferiority primary endpoint was not achieved (P=0.843 for non-inferiority).
In the overall MATRIX population, fluoroscopy times and DAP were higher with radial as compared with femoral access:
- Fluoroscopy time: 10 minutes (IQR:6-16) vs 9 minutes (IQR:5-15, P<0.0001)
- DAP (available in 7,570 procedures and 6,902 patients): 65 Gy*cm2 (IQR:29-120) vs 59 Gy*cm2 (IQR:26-110, P=0.0001)
In addition, thorax operator dose did not differ in the right radial at 84 µSv (IQR:47-146) compared with the left radial access at 52 µSv (IQR:33-92, P=0.15).
"Our study shows that radial access is associated with higher operator and patient radiation exposure compared to femoral access," Sciahbasi's group wrote. "Radial operators and institutions should be sensitized towards radiation risks and adopt adjunctive radio-protection measures."
The study had some limitations, specifically the use of thermoluminescent dosimeters, which allows only a cumulative analysis of the operator radiation dose. "The use of electronic dosimeters that show radiation dose at the end of each procedure would have allowed a better understanding, which factors might ameliorate, or even negate, the differences in radiation exposure observed between radial and femoral access," the authors acknowledged.
Also, patients were recruited in 78 centers in Italy, the Netherlands, Spain, and Sweden so operator experience and training may have differed.
"I think that most operators are not aware of the excess radiation danger [with radial access]," Sciahbasi said. "We want to make them aware of this danger so they can use practical precautions in limiting that exposure. Radial operators should pay special attention to radioprotective measures in order to minimize the effects of radiation to patients, staff, and themselves."
of Brigham and Women's Hospital in Boston, told 麻豆传媒 that "the radial artery is small, and it takes more time to do the procedure. But the patients love the radial approach, which is likely to have fewer complications."
"There are trade-offs. Every procedure has some possible complications," noted O'Gara, who was not involved in the study.
Disclosures
The MATRIX study was supported by The Medicines Company and Terumo.
Sciahbasi and O'Gara disclosed no relevant relationships with industry.
Some study co-authors disclosed multiple relevant relationships with industry including Astra Zeneca, The Medicines Company, Abbott Vascular, AB Medica, Innova HTS, Stentys, Amgen, Medtronic, Johnson & Johnson, Ablynx, Boehringer-Ingelheim, Eisai, Eli Lilly, Gilead Sciences, Nestle, and Novartis.
Primary Source
Journal of the American College of Cardiology
Sciahbasi A, et al "Radiation exposure and vascular access in acute coronary syndromes: The RADMatrix Trial" J Am Coll Cardiology 2017; DOI: 10.1016/j.jacc.2017.03.018.