Radiation Exposure for Percutaneous Interventions of Chronic Total Coronary Occlusions in a Multicenter Registry: The Influence of Operator Variability and Technical Set-up.

Radiation exposure is a limiting factor for percutaneous coronary interventions (PCI) of chronic total coronary occlusion (CTO) lesions. This study was designed to analyze changes in patient radiation dose for CTO-PCI and parameters associated with radiation dose. We analyzed a cohort of 12,136 procedures performed by 23 operators between 2012 and 2017 from the European Registry of CTO-PCI. Radiation exposure was recorded as air kerma (AK) and dose area product (DAP). A dose rate index (DRI) was calculated as AK per fluoroscopy time to normalize for individual differences in fluoroscopy time. The lesion complexity increased from Japanese-CTO (J-CTO) score of 2.19 ± 1.44 to 2.46 ± 1.28, with an increase of retrograde procedures from 31.1% to 40.7%; still, procedural success improved from 87.7% to 92.1%. Fluoroscopy time remained similar, but AK decreased by 14.9%, from 2.35 Gy (interquartile range [IQR], 1.29-4.14 Gy) to 2.00 Gy (IQR, 1.08-3.45 Gy) and DAP decreased by 21.5%, from 130 Gy•cm² (IQR, 70-241 Gy•cm²) to 102 Gy•cm² (IQR, 58-184 Gy•cm²). Radiation exposure was determined by the lesion complexity (J-CTO score) and procedural complexity (antegrade or retrograde). DRI was determined by fluoroscopy frame rate and type of equipment used, but the major influence remained interoperator differences. Radiation exposure decreased during the observation period despite an increase in lesion and procedural complexity. While many operators already achieved a goal of low radiation exposure, there were considerable interoperator differences in radiation management, indicating further potential for improvement.