Effects of reducing frame rate from 7.5 to 4 frames per second on radiation exposure in transcatheter atrial septal defect closure

OBJECTIVES: The aim of this study was to evaluate the reduction of frame rate from 7.5 to 4 frames per second on radiation exposure and to provide new standards of radiation exposure. BACKGROUND: Frame rate is a large contributor to radiation exposure. The use of 4 frames per second for closure of atrial septal defects has been reported not to affect the level of radiation exposure. METHODS: We retrospectively reviewed radiation data from all patients referred to our catheterisation laboratory for closure of an atrial septal defect between January, 2015 and June, 2017. Fluoroscopic time, dose area product (μGy.m2), and total air kerma (mGy) were collected. These values were compared according to the frame rate used for closure of atrial septal defects. RESULTS: A total of 49 atrial septal defects were closed using 7.5 frames per second and 85 using 4 frames per second. Baseline characteristics were similar in both groups. Procedural success was similar in both groups (100 versus 98.8%). Median total air kerma and dose area product were statistically lower in the 4 frames per second group (4 versus 1.3 mGy [p=0.00012]), 43.7 versus 13.1 μGy.m2 [p0.05). CONCLUSION: Reduction of frame rate allows reducing significantly the radiation exposure while maintaining excellent clinical results in transcatheter closure of atrial septal defects. We recommend implementing this little change in every laboratory in order to achieve drastic reduction of radiation exposure to the patients and laboratory personnel.