1. The Influence of Radial vs. Femoral Access on Acute Blood Loss in Patients Undergoing Percutaneous Coronary Intervention Amit Nanda 1, Amit P. Amin 2, Eesha Kelkar 2, Eric Novak 2, Mary Caruso 2, Adam C. Salisbury 3, Jasvindar Singh 2 1 UMKC School of Medicine, 2 Washington University in St Louis, MO, 3 St Luke’s Hospital Introduction Acute blood loss and anemia are common after acute myocardial infarction (AMI) and percutaneous coronary intervention (PCI) and are associated with higher morbidity and mortality. Although it is known that radial PCI reduces bleeding and vascular complications, whether it is independently associated with less blood loss is unknown. Methods Retrospectively identified 3,557 patients from a single hospital, undergoing PCI via radial and femoral approaches from Dec 1 st 2011- Jan 31 st 2014. Hemoglobin values before and after the PCI were recorded and the difference in hemoglobin was calculated as pre – post hemoglobin. The difference in hemoglobin drop by radial vs. femoral procedure was compared via the univariate Student’s t-test. A multivariable generalized estimating equation (GEE) model using robust standard errors to account for clustering within hemoglobin pre- and post-PCI values was developed, examining the drop in hemoglobin attributable to Radial vs. Femoral access, after adjusting for socio-demographic characteristics and patients’ risk factors and comorbidities. Most importantly, this model also adjusted for established confounders of overt bleeding and transfusion as well as the ceiling effect due to extremely high hemoglobin values > 16 g/dL at baseline. Results Radial PCI was performed in 148 (5%) of procedures. The mean hemoglobin drop after PCI was 1.18 g/dl for the entire cohort. The mean hemoglobin drop in those undergoing radial PCI was 0.95 g/dL as compared to 1.19 g/dL for femoral PCI, a difference in Hb 0.24 g/dL, P-value < 0.01. When adjusted for all the comorbidities and patient and procedural characteristics, the mean hemoglobin drop was still lower by 0.20 g/dL in the Radial group as compared to femoral group (95% CI -0.37 to -0.03 g/dL, P-value 0.019) (Fig 1). Summary When adjusted for all co-morbidities and patient and procedural characteristics, the mean hemoglobin drop was lower in the radial PCI group as compared to femoral PCI group. Clinically this may translate into lower bleeding complications in radial PCI compared to femoral PCI. Conclusion Radial PCI is independently associated with a smaller acute blood loss than femoral PCI. Radial PCI appears to be less invasive than femoral PCI and could represent the access of choice in those who are anemic at baseline. Further research is required to ascertain if lower blood loss with radial PCI translates into, and is the mechanism responsible for improved outcomes after Radial PCI. References 1.Doyle B.J., Ting H.H., Bell M.R.; Major femoral bleeding complications after percutaneous coronary intervention: incidence, predictors, and impact on long- term survival among 17,901 patients treated at the Mayo Clinic from 1994 to 2005. J Am Coll Cardiol Intv. 2. Manoukian, SV et al J Am Coll Cardiol. 2007;49(12):1362-8. 3.Feldman DN, Swaminathan RV, Kaltenbach LA, et al. Adoption of radial access and comparison of outcomes to femoral access in percutaneous coronary intervention. Circulation 2013 Fig 1: Independent predictors of hemoglobin drop after PCI.