15.0%, C - 20.4%, D - 11.9%, p=0.03). Following adjust- ment for differences in baseline and operative characteristics, administration of the current formulation of PPC brand hep- arin was associated with the highest likelihood of receiving FFP (A - OR 1.00; B - OR 1.73, p=0.04; C - OR 1.94, p=0.01; D - OR 1.01, p=0.98) and PLT (A - OR 1.00; B - OR 1.88, p=0.03; C - OR 2.44, p=0.001; D - OR 1.26, p=0.42). CONCLUSION: In patients undergoing cardiac surgery, PPC brand heparin resulted in increased heparin dosing, peri-oper- ative bleeding and peri-operative blood product transfusion in patients undergoing cardiac surgery. The results of this study suggest that an alternative to PPC brand heparin be used when placing patients on cardiopulmonary bypass. 506 DEPRESSION AND CARDIAC SURGERY: PREDICTORS AND THE IMPACT OF PHYSICAL ACTIVITY D Horne, S Kehler, G Kaoukis, B Hiebert, E Garcia, TA Duhamel, RC Arora Winnipeg, Manitoba BACKGROUND: Depression has received increased attention af- ter cardiac surgery. The “Impact of Physical Activity on De- pression after Cardiac Surgery”-study (IPAD-CS) investigators report: 1) which factors predict depression, 2) the impact phys- ical activity has on depressed patients after cardiac surgery. METHODS: Patients awaiting non-emergent surgery (n=436), completed the “Patient Health Questionnaire-9” (PHQ-9) for depression, as well as the International Physical Activity Ques- tionnaire short version (IPAQ-short) at 4 time points: pre- operatively (Q1, n=436), hospital discharge (Q2, n=374), 3 months- (Q3, n=318) and 6 months (Q4, n=342) post-op- eratively. At baseline patients were categorized into “depression naïve”-, “at risk”- or “depressed”-groups based upon their PHQ-9 scores. At each time point patients were identified as “Not Depressed” (PHQ-9-score 0-3), “Possibly Depressed” (4-9) or “Depressed” (9). Univariate and multivariate logistic regression analysis was used to identify independent baseline- and peri-operative variables for predicting depression. RESULTS: Prevalence of any depression from Q1-Q4 was 23.6%, 37.7%, 21.4% and 23.4% respectively. Multivariate logistic regression identified 8 independent predictors of de- pression: Pre-operative left ventricular ejection fraction (LVEF) 30-49% (Q1: p=0.042), LVEF 30% (Q1: p=0.026), Physical inactivity (Q1: p=0.002), baseline “At Risk”-group (Q2: p=0.004), baseline “Depressed”-group (Q2: p0.0001, Q3: p0.0001, Q4: p0.0001), hospital length of stay  7 days (Q2: p=0.039), post-operative stressful event (Q3: p0.0001, Q4: p0.0001), cardiopulmonary by- pass time  120 minutes (Q4: p=0.004). Figure 1 below in- dicates the median PHQ-9 depression scores at each time point for each group. Patients from the “Depressed”-group whose PHQ-9 scores improved to non-depressed levels at Q3 and Q4 had significantly higher levels of physical activity (median IPAQ minutes/week 297.5 vs. 177.5 (Q3 vs. Q1, p=0.04) and 445 vs. 230 (Q4 vs.Q1, p=0.04). CONCLUSION: We report one of the largest prospective series in- vestigating the interaction of depression and physical activity be- fore and after cardiac surgery. After an initial increase in prevalence of depression at discharge, there was a return to pre-operative levels at 3- and 6-month follow-up. Pre-operative depression and post- operative stressful events were the strongest predictors of depres- sion after cardiac surgery, and increased physical activity levels were associated with improvement in depressed patients’ mood. We’ve found a heterogeneous depressive response after cardiac surgery. Notably, a previously not quantified group of “at risk”- patients experiences a clinically significant increase in depressive symptoms indicating a need for improved routine screening for depression in the perioperative setting. Featured Research 507 TRANSCATHETER AORTIC VALVE IMPLANTATION VIA THE LEFT AXILLARY ARTERY APPROACH: A SINGLE CENTER EXPERIENCE WITH THE MEDTRONIC COREVALVE PROSTHESIS M Laflamme, L Chan, A Mazine, Y Lamarche, R Ibrahim, P Demers, R Bonan, R Cartier, A Asgar Montréal, Québec BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an accepted alternative treatment for severe symptomatic aortic stenosis in high risk and inoperable patients. Femoral or trans- S286 Canadian Journal of Cardiology Volume 28 2012