The Influence of Radiographic Equipment, Setup, and Operator Experience on Radiation Exposure in Chronic Total Occlusion Interventions

High radiation exposure is a significant risk with recanalizations for chronic total coronary occlusions (CTO). To analyze the influence of radiographic equipment, radiation protocols, and operator experience on radiation exposure. We analyzed 17,769 procedures by 27 operators from a multicenter European Registry between 2015 and 2023. Thirteen operators had an experience > 10 years (Gen1), and 14 entered the registry after 2015 (Gen2). AirKerma (AK), dose area product (DAP), the dose rate index (DRI) as AK per fluoroscopy time (FT), and the collimation index (CLI) as DAP per AK were calculated to assess inter-operator variability. Despite increased lesion complexity (2015-17: CASTLE score 1.83 ± 1.10, 2021-23: 2.20 ± 1.19; p < 0.001), AK and DAP were reduced by 45%. Gen1 operators treated more complex lesions than Gen 2 (2.05 ± 1.13 vs. 1.85 ± 1.16; p < 0.001) at more extended FT (38.4 [23-61] vs. 34.0 [20-57]; p < 0.001) than Gen2 with slightly higher AK (1.6 [0.89-2.8] Gy vs. 1.4 [0.8-2.54]; p < 0.001), but DRI was similar (42.9 [27.7-64.3] vs. [28.0-62.1]). In 2015-17, operators with Philips Clarity had a lower median AK (1.7 Gy; p < 0.001) than other vendors (Siemens 2.1 Gy; General Electric 2.8 Gy), but with updated equipment, Philips systems had slightly higher AK (1.2 Gy) than Siemens systems (1.0 Gy; p < 0.001). Inter-operator variability regarding DRI improved over time, but collimation did not change. Radiation exposure for CTO PCI was reduced for both long-time and recent CTO operators during 9 years. Equipment updates were instrumental to improved radiation management, but inter-operator differences remained regarding dose management and collimation.