Abstract 142: Feel the Burn, PCI Advances Increase Radiation Exposure of Patients

Abstract

Objective: Interventional cardiology success in revascularization and structural heart has an unseen cost. Complex, prolonged cases increase exposure of patients (Pts) and staff to ionizing radiation. The increased radiation has direct deterministic effects (air kerma; skin dose) and stochastic effects (air kerma x area product). Fluoro time is also monitored. Individual MD and overall lab perfomance exposure guidelines for the laboratory have been set [peak Skin dose < 5 Gray, Air kerma x Area product (DAP) < 200 Gray*cm 2 , fluoro time < 60 min). Procedure: Exposure for cath pts was tracked. MD, pt, anatomic, procedural variables associated with high exposures were identified and specific interventions to minimize radiation exposure identified. Results: Over a year period 17.2% of cases [237/1375] received high skin [6.0%; 83/1375] or DAP radiation [17.2%; 237/1375]. No pt sequelae were identified on follow-up for doses as high as 13.251 Gray, 775 Gy*cm2, fluoro time 119.9 min. Fluoro time was not a useful measure; it did not correlate with either skin dose or DAP, reflecting variable use of fluoro compared to cine, pt BMI, differing fluoro rates (ranging from 4 fps to 15 fps). Frequency of high radiation exposure by MD (with over 50 cases/year) ranged from 4.5% - 28.3% of interventions [Skin dose 1.1%-15.4% and DAP 4.5%-28.3%]. Pt risk factors included: morbid obesity, multivessel/multilesion interventions, lesion complexity [particularly calcified lesions and CTOs], complex structural heart procedures. MD factors included: highly angled views, # of cine runs [8.9% (122/1375) > 40 runs, 3.7% (51/1375) > 50 runs, 0.8% 14/1375) > 75 runs], staged procedures versus multivessel/ multilesion procedures, trainee staffing. Default radiation exposure settings of Xray equipment are now set at lower levels acceptable for imaging (MD can modify). MD feedback and interventions to decrease radiation exposure are ongoing, targeting: MD continued case awareness of displayed radiation dose with appropriate staging, use of lowest visually acceptable fluoro rates, shortening and minimizing cine runs where possible, store/map reference images, vary imaging angle and decrease where possible steep angulations, optimal collimation. The MDs who have adopted these practices have the lowest pt exposure rates [skin dose 1.4-5.1%, DAP 4.5-8.6% guideline tracked]. Opportunities for improvement are evident in current practice but also include improved tracking of pt medical treatment related exposure, upgrades in Xray equipment. Conclusions: Advances in equipment and MD experience have been offset by the increasing disease complexity of attempted interventions [including CTOs]. Pt factors and MD practice both contribute to optimal radiation safety [ALARA]. MD practice is a key modifiable variable to promote radiation safety, affecting exposure of pts and staff.