Leukemia Risk After Cardiac Fluoroscopic Interventions Stratified by Procedure Number, Exposure Latent Time, and Sex: A Nationwide Population-Based Case-Control Study

A number of cardiac fluoroscopic interventions have increased rapidly worldwide over the past decade. Percutaneous transluminal coronary angioplasty (PTCA) and stent implantation have become increasingly popular, and these advancements have allowed patients to receive repetitive treatments for restenosis. However, these advancements also significantly increase radiation exposure that may lead to higher cumulative doses of radiation. In the present study, a nationwide population-based case-controlled study was used to explore the risk of leukemia after cardiac angiographic fluoroscopic intervention. A total of 5026 patients with leukemia and 100,520 control patients matched for age and sex (1:20) by a propensity score method without any cancer history were enrolled using the Registry Data for Catastrophic Illness and the National Health Insurance Research Database (NHIRD) of Taiwan between 2008 and 2010. All subjects were retrospectively surveyed (from year 2000) to determine receipt of cardiac fluoroscopic interventions. Data were analyzed using conditional logistic regression models, and estimated crude and adjusted odds ratios (95% confidence interval). After adjusting for age, gender, and comorbidities, PTCA was found to be associated with an increased risk of leukemia with an adjusted OR of 1.566 (95% CI, 1.282–1.912), whereas coronary angiography alone without PTCA and cardiac electrophysiologic study were not. Our results also showed that an increased frequency of PTCA and coronary angiography was associated with a higher risk of leukemia (adjusted OR: 1.326 to 1.530 [all P < 0.05]). Gender subgroup analyses demonstrated that men were associated with a higher risk of leukemia compared with women. These results provide additional data in the quantification of the long-term health effects of radiation exposure derived from the cardiac fluoroscopic diagnostic and therapeutic intervention. PTCA alone or PTCA with coronary angiography was associated with an elevated risk of leukemia. Continued follow-up of existing cohorts will be valuable to help assess lifetime risks of cancer.