Efficacy of Low-Dose Compared With Standard-Dose Radiation for Cardiac Catheterization and Intervention (KAR RAD Study)

OBJECTIVES: We evaluated the efficacy of low-dose (LD) radiation (≤7.5 frames/second [f/s]) compared with standard-dose (SD) radiation (≥10 f/s) in cardiac catheterization (CC) and percutaneous coronary intervention (PCI). Patients undergoing CC with LD vs SD radiation have not been previously studied. METHODS: We performed an observational study of 452 consecutive patients (61 ± 12 years) who had coronary angiography or PCI from September 2016 to September 2017. Patients were divided into an LD radiation group (n = 136) consisting of 0.5 f/s and 1 f/s (n = 73), 4 f/s (n = 40), or 7.5 f/s fluoroscopy (n = 23) with 7.5 f/s cine angiography vs an SD group (n = 316) consisting of 10 f/s (n = 250), 15 f/s (n = 64), or 30 f/s fluoroscopy (n = 2) and 10-30 f/s cine angiography. Primary endpoints included air kerma, dose area product (DAP), fluoroscopy time, and contrast use. RESULTS: Compared with SD radiation, LD radiation was associated with a significant reduction in air kerma (100.70 mGy [IQR, 46.42-233.35 mGy] vs 660.96 mGy [IQR, 362.78-1373.65 mGy]; P<.001), DAP (723.60 μGy•m² [IQR, 313.09-2328.22 μGy•m²] vs 5203.40 μGy•m² [IQR, 2743.55-10064.71 μGy•m²]; P<.001), and contrast use (100 mL [IQR, 60-150 mL] vs 115 mL [IQR, 80-180 mL]; P<.03). No difference in fluoroscopy time was noted (13.33 min [IQR, 6.93-25.55 min] vs 12.75 min [IQR, 7.75-22.55 min]; P=.95). CONCLUSIONS: LD radiation in CC was efficacious, with significant radiation reduction and without an increase in fluoroscopy time or contrast utilization. All patients underwent successful LD radiation catheterization without conversion to SD.