Diagnostic testing for coronary artery disease shows marked worldwide variation in radiation dose, particularly affecting patients in low- and middle-income countries and those undergoing CCTA.
Observational
Yes
There is a critical need for training, standardized protocols, and updated equipment to reduce the marked worldwide variation in radiation doses during CAD diagnostic imaging, particularly in low- and middle-income countries.
IMPORTANCE: In recent decades, there has been marked worldwide growth in diagnostic testing for coronary artery disease (CAD), with several common imaging modalities exposing patients to ionizing radiation. OBJECTIVE: To examine worldwide radiation doses for patients undergoing noninvasive CAD diagnostic testing. DESIGN, SETTING, AND PARTICIPANTS: This worldwide, cross-sectional study was conducted of radiation dose from noninvasive CAD imaging in 2023, using a consecutive sample of all 19 302 adults undergoing noninvasive CAD diagnostic testing at 742 centers in 101 countries during a single week in October to December 2023. EXPOSURES: Participants underwent CAD testing with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) nuclear cardiac imaging, cardiac computed tomography for coronary artery calcium scoring (CACS), or coronary computed tomography angiography (CCTA). MAIN OUTCOMES AND MEASURES: The primary outcomes were radiation effective dose to patients and the percentage of centers with median effective dose less than or equal to 9 mSv, as recommended in guidelines. RESULTS: Of 19 302 patients, 8515 (44%) were females and the median (IQR) age was 63 (54-71) years. Effective dose varied considerably across diagnostic modalities, with median (IQR) effective dose of 1.2 (0.7-2.2) mSv for CACS, 2.0 (1.6-2.4) mSv for PET, 6.5 (3.9-8.6) mSv for SPECT, and 7.4 (3.5-15.5) mSv for CCTA. Significantly more centers performing nuclear cardiology than CCTA (81% vs 56%; P < .001) and patients undergoing nuclear cardiology studies than CCTA (79% vs 56%; P < .001) achieved median dose of less than or equal to 9 mSv. Doses for the same procedure differed significantly between world regions, being lowest in Western Europe (median IQR, 4.8 2.3-7.3 mSv for nuclear cardiology and 4.6 2.4-9.8 mSv for CCTA) and highest in Latin America for nuclear cardiology (median IQR, 7.8 5.3-9.7 mSv) and Africa (median IQR, 25.2 14.7-35.3 mSv) for CCTA (P < .001 for all). In regression modeling, there was an inverse relationship between country income level and dose. Patient dose was 20% (95% CI, 3.6%-38.4%) higher in low- and middle-income countries than in high-income countries for nuclear cardiology, and as much as 96% (95% CI, 41.7%-170.8%) higher in low- and lower-middle-income countries than in high-income countries for CCTA (P < .001). Marked variation was observed within income levels and world regions. CONCLUSIONS AND RELEVANCE: Given increasing rates of CAD worldwide, these findings of marked variation in radiation dose to patients from diagnostic testing identify a critical need for training, standardized protocols, and updated equipment to reduce radiation worldwide. This especially affects patients in low- and middle-income countries and patients undergoing CCTA. There are therefore important opportunities to improve the quality of CAD diagnosis for patients across the globe.
“This study shows that where a patient lives, the resources available to a health system and how those resources are used can strongly influence how much radiation they receive — even when undergoing the same test. These differences are not inevitable. In many cases, the technology and knowledge to reduce dose already exist. The challenge is ensuring that they are applied consistently and equitably across the world.”
Einstein et al. (2026) conducted an observational in Coronary Artery Disease (CAD). Diagnostic imaging (CCTA) was evaluated on Radiation dose variation. Diagnostic testing for coronary artery disease shows marked worldwide variation in radiation dose, particularly affecting patients in low- and middle-income countries and those undergoing CCTA.