RESUMO
BACKGROUND: Patient exposure to radiation during the management of coronary heart disease (CHD) can be reduced with more efficient technologies in nuclear medicine, such as the Cadmium-Zinc-Telluride (CZT) gamma-camera for myocardial perfusion imaging (MPI) studies. However, it has been suggested that CZT has lower specificity, which might lead to more downstream radiological procedures, particularly among obese individuals. METHODS AND RESULTS: We evaluated 244 patients with suspected CHD who underwent CZT-SPECT and matched 1:1 according to sex, age, and body mass index (BMI) with those undergoing MPI study with the Anger gamma-camera (Anger-SPECT). The outcome was the total radiation exposure from the MPI study added to the radiation exposure from all subsequent cardiac examinations during a 90-day follow-up. The total radiation dose after 90 days was significantly lower in the CZT-SPECT group (6.4 ± 4.8 vs 9.5±4.9 mSv, P < .001). After adjusting for potential confounders, CZT-SPECT remained associated with lower total radiation dose, but it significantly attenuated among obese individuals (Beta coefficient - 3.73 ± 0.86 for BMI < 30 vs - 2.30 ± 0.92 for BMI ≥ 30 Kg/m2, P for interaction < 0.032). CONCLUSIONS: CZT-SPECT was associated with lower total radiation doses compared to Anger-SPECT, albeit this benefit may be attenuated in obese individuals.