Radiation Exposure During Cardiac Cath on the Decline

By Brandon May

September 15, 2021

NEW YORK (Reuters Health) - Radiation exposure associated with diagnostic cardiac catheterization (DCC) has dropped over the past decade, possibly due to technological advances and greater implementation of dose-saving techniques, according to new findings.

In the PROTECTION VII study, researchers took a look back at more than 5.4 million DCC procedures in Germany that were registered in the country's quality-assurance program for cardiac catheterization between 2008 and 2018. They analyzed radiation exposure by assessing the radiation dose-area product (DAP) and the total radiation time.

Patients had a median age of 70 years at time of the cardiac catheterization, Dr. Thomas Stocker of Ludwig Maximilian University of Munich and colleagues report in JACC: Cardiovascular Interventions. Almost one in ten had a history of coronary-artery-bypass grafting.

Leading indications for DCC in the cohort included suspected coronary-artery disease (CAD), known CAD and acute coronary syndrome.

For all DCC procedures, median DAP for all patients was 1,856 cGy*cm2 (effective dose, 4.1 mSv), with exposure levels varying significantly across different indications for DCC; the median radiation time was 3.0 minutes.

Median DAP decreased significantly over the study from 1,856 cGy*cm2 to 1,229 cGy*cm2, a 47% drop (P<0.001). The effective dose fell from 5.1 mSv to 2.7 mSv.

Independent variables associated with increased DAP during the observational period, according to multivariable regression analysis, included male sex (+793 cGy*cm2), advanced age (+36 cGy*cm2 per 10-year increase), history of coronary-artery-bypass grafting (+961 cGy*cm2), heart failure (+225 cGy*cm2), and the various procedural indications.

There was significant variation in DAP between the different catheterization laboratories. According to the researchers, this suggests that some sites were capable of reducing the radiation dose after implementing certain dose-saving techniques, such as frame-rate reduction and avoiding unfavorable angulations. Technical advancements in recent years, such as those made in noise-reduction technology, may also have played a role in the reduction of radiation exposure, Dr. Stocker and his colleagues say.

Dr. Mladen Vidovich of the University of Illinois at Chicago told Reuters Health by phone that the findings "open possibilities to learn and improve on what's currently being done across centers." Doing so, he suggests, may help further reduce the radiation exposure for patients as well as clinicians, who tend to receive the majority of radiation from day-to-day cumulative exposure.

According to Dr. Vidovich, who wasn't involved in the study, clinicians should continue to reassure patients, some of whom may be concerned about radiation exposure, that the benefits of DCC potentially outweigh the risks.

"Damage to the patient is usually negligible," he said. "Doctors who try hard to help patients, however, somehow forget that they're getting the radiation as well, which also underscores the importance of improving protection for clinicians and other necessary staff."

Dr. Stocker did not reply to an emailed request for comments.

SOURCE: https://bit.ly/3BYjWtu JACC: Cardiovascular Interventions, online September 13, 2021.