Predictors of Radiation Exposure During ST Elevation Myocardial Infarction (STEMI)

Abstract

Aims: Coronary angiography accounts for a disproportionately high amount of medical radiation in the adult population. We sought to determine the predictors of increased radiation exposure during ST elevation myocardial infarction (STEMI). Methods & Results: Between January 2011 and December 2018 a total of 2,151 patients presented to our centre for primary percutaneous coronary intervention (pPCI) or rescue PCI. Fluoroscopy time and air Kerma dosage were recorded. Mean age was 65.6 ± 13.7 yrs with 21.5% females. The mean body mass index (BMI) was 27.39 ± 4.65 kg/m2. The median fluoroscopy time was 11.3 minutes (IQR: 8.2-16.7 minutes), whilst the median air Kerma was 810 mGy (IQR: 506.0-1274.3mGy). Older age was associated with a greater fluoroscopy time (p < 0.0001), but not air Kerma (p = 0.70), whilst female sex was associated with lower fluoroscopy time (12.8 mins vs 14.5 mins, p < 0.0001) and lower air Kerma (854.8mGy vs 1106.9mGy, p < 0.0001). A higher BMI was associated with a higher air Kerma (p < 0.0001) but not fluoroscopy time (p = 0.17). pPCI performed during day-time hours (8:00am – 8:00pm) was associated with higher fluoroscopy time (19.3 mins vs 14.1 mins, p < 0.0005) and air Kerma (1238.4 mGy vs 1006.7 mGy, p < 0.0005). In multivariate analysis, time of day remained independently predictive of fluoroscopy time (p < 0.05) and air Kerma (p < 0.0005). Conclusions: During pPCI for patients presenting with a STEMI, age, sex, BMI and timing of the procedure impact the fluoroscopy time and radiation dosage. An appreciation of these factors and may identify patients whereby strategies to reduce radiation dosage should be implemented.