An evaluation of radiation exposure to a large population of patients undergoing PCI and coronary angiography (CA) may help identify methods for optimizing patient safety, according to a study published online April 9 in Catheterization and Cardiovascular Interventions.

Previous research has shown that PCI and CA are among the 20 imaging procedures with the largest contribution to annual cumulative radiation doses. Though guidelines have been created to ensure individual justification for a procedure and its optimization, data from large populations are scare about patient radiation exposure during interventional coronary procedures.

In this study, lead author Jean-Louis Georges, MD, of the Centre Hospitalier de Versailles in France, and colleagues evaluated current practices for patient radiation protection during a series of PCIs and CAs, updated patient diagnostic reference levels and analyzed factors associated with radiation exposure variation in clinical practice.

Using RAY’ACT, a multicenter, nationwide French survey that retrospectively analyzes radiation parameters, Georges et al were able to gather data from 33,937 CAs and 27,823 PCIs. They discovered that Kerma-area product  (KAP) was registered in 91.5 percent of procedures for CA and 91.1 percent for PCI. Fluoroscopy time was registered in 87.5 percent of the 44 participating centers and in 83.1 percent of procedures.

Variability across centers was high, the researchers observed. Old equipment and routine left ventriculography were more common and number of registered frames and frame rate were higher in centers delivering high doses. The median dose for the radial route was 26.8 Gycm² in CA procedures and 28.1 Gycm² for the femoral route, demonstrating respective lower and higher dose associations. The median KAP was 55.6 Gycm² and 59.4 Gycm² for PCI, respectively.

“From these data, we can update the reference values, and provide information on the need and the methods for optimizing radiation dose to patients during CA and PCI. Suggested reference levels for KAP are 45 Gycm² for CA (9 mSv) and 95 Gycm² (19 mSv) for overall PCI,” wrote Georges and colleagues.

They identified the number of frames, average frame rate used in the center and routine left ventriculography as procedure-related factors that contributed to differences between high and low-dose centers. The authors suggested that these parameters, which are operator-controlled, be the priority of an optimization program target.