Ionizing radiation exposure in complex percutaneous coronary intervention: Defining local diagnostic reference levels in the catheterization laboratory

Introduction and objectives: Concerns regarding the consequences of ionizing radiation (IR) have been increasing in the field of interventional cardiology (IC). There is little information on reported national and local radiation diagnostic reference levels (DRLs) in catheterization laboratories in Portugal. This study was designed to assess the IR dose exposure during complex percutaneous coronary intervention (PCI), and to set the respective DRLs and future achievable doses (ADs). Methods: This was a retrospective cohort study which took place between 2019 and 2020, including patients who underwent complex PCI. Complex PCI was defined as all procedures that encompass treatment of chronic total occlusions (CTO) or left main coronary artery. DRLs were defined as the 75th percentile of the distribution of the median values of air kerma area product (P-KA) and cumulative air kerma (K-a,K-r). ADs were set at the 50th percentile of the study dose distribution. Multivariate analysis was performed using linear regression to identify predictors significantly associated with radiation dose (K-a,K-r). Results: A total of 242 patients were included in the analysis. Most patients underwent a CTO procedure (146, 60.3%). Patients were aged 67.9 +/- 11.2 years and mostly male (81.4%). DRLs were set in K-a,K-r (3012 mGy) and P-KA (162 Gy cm(2)) for complex PCI. ADs were also set in K-a,K-r (1917 mGy) and P-KA (101 Gy cm(2)). Independent predictors of K-a,K-r with a positive correlation were P-KA (0.893, p<0.001), fluoroscopy time (0.520, p<0.001) and PCI time (0.521, p<0.001). Conclusions: This study reports the results of IR in complex PCI. DRLs were set for IR dose exposure measured in K-a,K-r (3012 mGy) and P-KA (162 Gy cm(2)). ADs, values to be achieved in future assessment, were set to K-a,K-r (1917 mGy) and P-KA (101 Gy cm(2)).