Survey Adds To Mounting Evidence That Cath Lab Work Has Radiation-Related Health Effects
Interventional cardiologists and other personnel who work in environments with fluoroscopy-guided procedures appear to have more health problems than their colleagues in the same field who are not exposed to radiation, a survey suggests. The health problems range from eye, skin, and orthopedic problems to mental health issues, and cancers.
Researchers led by Maria Grazia Andreassi, MSc, PhD (CNR Institute of Clinical Physiology, Pisa, Italy), say “every effort should be made to raise the radiation awareness in the professional communities of interventional cardiologists and cardiac electrophysiologists, promoting justification of the examination, optimization of the dose, and maximal protection of the radiation workers.”
They surveyed 466 physicians and other staff members with an average of 10 years of experience working in interventional cardiology or electrophysiology laboratories as well as 280 individuals working in the cardiology field but having no exposure, including physicians, researchers, nurses, and administrative staff. All completed a questionnaire about their present and past medical history, medication use, duration of work, and frequency of cigarette and alcohol use. An occupational radiological risk score, which combined length of employment, individual caseload, and proximity to the radiation source, was formulated for each participant.
Physical, Psychological Differences Evident
Reporting their results online April 12, 2016, ahead of publication in Circulation: Cardiovascular Interventions, Andreassi and colleagues found that not only were potential radiation-related health issues such as skin lesions, orthopedic problems (back, neck, knee), cataracts, and cancers more prevalent in radiation-exposed vs unexposed workers, they were also more common among physicians vs technicians and nurses, and among those with longer vs shorter work histories. Across every disease category, those with 16 or more years of working in an environment with fluoroscopy-guided procedures had the highest event rates.
The prevalence of anxiety/depression was also increased among the radiation-exposed group—at a rate 6 times higher than unexposed colleagues, while the rate of thyroid disease was doubled. Radiation-exposed workers also had greater rates of hypertension and hypercholesterolemia, but not of cardiovascular events.
Rates of health problems in the radiation-exposed versus unexposed groups were confirmed in multiple logistic regression analysis.
“Unfortunately, cardiologists pay little heed to monthly or cumulative reports of radiation exposure. And recent studies confirm that simple, effective protection measures—such as a lead curtain, protection glasses and thyroid collars—are not used by the majority of exposed cardiologists,” Andreassi said in a press release.
Exposure-Related Associations Abound
Among the health problems reported in the survey and previously described in the literature, radiation-induced cancer is “the most alarming and serious” of the long-term occupational risks for interventional cardiologists, the study authors write. Concerns of brain cancer on the left side of the head, which is known to be more exposed to radiation and least protected by standard shielding, have been apparent in the literature as far back as 1998, they note.
“Although the evidence supporting an increase in radiation-induced cancer among interventional cardiologists remains inconclusive, molecular studies showed that interventional cardiologists have a two-fold increase of chromosomal damage (surrogate biomarkers of cancer risk) in circulating lymphocytes than clinical cardiologists,” Andreassi and colleagues write. Recently, findings from the International Nuclear Workers cohort showed strong evidence of positive associations between protracted low-dose radiation exposure and leukemia.
Interestingly, Andreassi and colleagues point out that radiation-related increases in hypertension and elevated serum cholesterol concentrations have also been seen in atomic-bomb survivors, more than half of whom were exposed to an average dose of < 50 mSv. In the press release, Andreassi notes that experienced, busy interventional cardiologists and electrophysiologists typically are exposed to about 5 mSv yearly. In a study published last year, her group also found that cath lab workers showed early signs of vascular aging and subclinical atherosclerosis. They suggest that chronic low-dose rate radiation “triggers changes in the endothelial cell biology that induce the onset of premature senescence, and these alterations may in part be responsible for the increased risk of chronic low-dose radiation–associated cardiovascular disease.”
As for the higher incidence of anxiety and depression in the radiation workers, Andreassi and colleagues hypothesize that this may be related to “high stress and psychological strain,” or a direct effect of radiation exposure to the head of the operator, resulting in “hippocampal neurogenesis and neuronal plasticity, with possible negative effects on mood stability and psychiatric morbidity.”
Stress a Likelier Culprit
Commenting for TCTMD, Stephen Balter, PhD, of Columbia University Medical Center (New York, NY), said the biggest flaw with the study is that everything was assumed to stem from radiation.
“It’s a high-stress job and I’m not surprised that there are health risks associated with doing the job, but these things are unlikely to be associated with radiation per se,” Balter said. “I think people trying to do the best they can are stressed out, and that’s reflected in their mental state and in their chemistry.”
Other than cataracts, which have a long, documented history in operators and others routinely exposed to occupational radiation, the other health issues such as cancers have not been substantiated in the literature as related to exposure, he added.
“The message is you have to be careful, but there’s no reason for panic,” Balter commented, adding that enforcing the wearing of radiation protection glasses and other gear among cath lab workers remains a challenge.
Profit Over People
Even though the current study is limited, there is “more than enough information for us to conclude that the interventional catheterization laboratory is not a healthy workplace,” observe Lloyd W. Klein, MD and Mugurel Bazavan, MD (Rush Medical College, Chicago, IL), in an accompanying editorial.
Despite the known risks to operators, the technology used in cath labs has outpaced safety-related changes in cath lab design and personnel protection, they say, primarily due to a profit mentality on the part of administrators that values talented, young, and inexpensive workers who can be readily replaced.
“Certainly, investing money in an innovative cath laboratory design to protect its workers is hardly cost-effective when nurturing a long career is not the goal of management,” Klein and Bazavan write. “We call on industry and hospital administration to provide responsible stewardship, and for physician societies and interventional leaders to advocate visibly and set new priorities, so that those of us who choose to help patients live a longer and healthier life can ourselves enjoy a long and healthy career, one that allows us to use all the magnificent and cherished skills we have dedicated years to master.”
- Andreassi MG, Piccaluga E, Guagliumi G, et al. Occupational health risks in cardiac catheterization laboratory workers. Circ Cardiovasc Interv. 2016;Epub ahead of print.
- Klein LW, Bazavan M. The economic imperatives underlying the occupational health hazards of the cardiac catheterization laboratory. Circ Cardiovasc Interv. 2016;Epub ahead of print.
- Andreassi, Klein, and Bazavan report no relevant conflicts of interest.
- Balter reports serving on the speakers’ bureau for Mavig, a manufacturer of radiation-protection supplies.