Patient Radiation Exposure Similar with Radial, Femoral Access

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Performing percutaneous coronary intervention (PCI) and coronary angiography via the radial approach does not impart any excess radiation to patients beyond what occurs during femoral access. The findings, published in the July 2012 issue of JACC: Cardiovascular Interventions, hold true even after correcting for procedural complexity.

For the study, Jan J. Piek, MD, PhD, of the University of Amsterdam (Amsterdam, the Netherlands), and colleagues collected registry data from 3,973 catheterizations (3,521 PCI, 452 coronary angiography) performed between June 2004 and December 2008. Radial access was used in 34.4% of PCI cases and 30.5% of angiograms.

Overall, the median dose-area product value was 69 Gy·cm² for either radial or femoral access. Median fluoroscopy time, however, was greater in femoral patients compared with those treated via radial access (12.4 minutes vs. 11.0 minutes; P < 0.001).

Looking separately at PCI and diagnostic coronary angiography, radiation exposure still did not differ by access route (table 1).

Table 1. Median Radiation Exposure

On multivariate analysis, independent predictors of radiation exposure were male sex, body mass index, number of lesions, type C lesions, right coronary artery lesions, left circumflex coronary lesions, and type of imaging system. After adjusting for these factors, radial access was not a predictor of radiation exposure. Based on a prediction model, the observed radiation exposure in patients undergoing radial access was not higher than the expected exposure in patients treated via the femoral route (71.5 ± 2.3 Gy·cm² vs. 79.8 ± 1.8 Gy·cm²).

Radiation exposure decreased over the course of the study along with increasing operator experience (88.2 ± 2.4 Gy·cm² in 2004-2005 vs. 66.2 ± 2.3 Gy·cm² in 2007-2008).

Physician Exposure Still a Concern

“We hope that the paper creates awareness regarding the radiation exposure of patients,” Dr. Piek told TCTMD in an e-mail communication. “Increased radiation exposure is probably not a reason to refrain from a radial approach.”

However, since physician radiation exposure was not measured, Dr. Piek noted that future studies should focus on this topic. “During interventional procedures performed by the radial route, interventional cardiologists are usually closer to patients than during procedures performed by the femoral route,” he said. “Since the intensity of scattered radiation close to patients is higher than the intensity at greater distances, it is possible that the radiation exposure of interventional cardiologists from procedures performed by the radial route is higher compared to exposure from procedures performed by the femoral route.”

In a telephone interview with TCTMD, James Tift Mann III, MD, of Wake Heart and Vascular Associates (Raleigh, NC), said the study gels with the current literature. Most of the newer trials showing an increase in radiation with transradial access have been based on procedures conducted by “relatively new operators,” he observed, adding that there is “a direct correlation between the learning curve and radiation exposure.”

Nevertheless, operator and patient radiation exposure are “one and the same,” Dr. Mann continued. “Numerous studies confirm that’s not an issue.”

A ‘Hidden Bonus’

The study’s “hidden bonus,” according to Stephen Balter, PhD, of Columbia University Medical Center (New York, NY), is that it provides a benchmark for hospitals around the country. “As more people collect the data and share [them],” he told TCTMD in a telephone interview, “it’s possible to see how we’re doing compared to the rest of the universe.”

With all of the conversation regarding the risks and benefits of radial compared with femoral access, the study “shows that at least as far as the patients go, [access route] doesn’t make a practical difference. So worrying about radiation no longer becomes a factor,” he concluded.

 

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Source:
Kuipers G, Delewi R, Velders XL, et al. Radiation exposure during percutaneous coronary interventions and coronary angiograms performed by the radial compared with the femoral route. J Am Coll Cardiol Intv. 2012;5:752-757.

 

 

Related Stories:

• Operator Radiation Dose Still Higher with Radial Access Despite Patient Shielding
• Radial Access Ups Radiation Exposure for Patients, Physicians vs. Femoral Route
• Extra Radiation from Radial Procedures Declines with Operator Experience

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