Abstracts S209 ( 559) Decreased Pulmonary Artery Compliance Is Associated With Right Heart Failure and Reduced 6-Month Survival After Left Ventricular Assist Device E.W. Grandin , 1 J.A. Mazurek, 1 P. Zamani, 1 G.S. Troutman, 2 E. Vorovich, 1 E.Y. Birati, 1 S. Banerji, 3 D. Pedrotty, 1 J.N. Kirkpatrick, 1 K.B. Margulies, 1 P. Atluri, 4 J.E. Rame. 1 1 Division of Cardiovascular Medicine, University of Pennsylvania, Philadelphia, PA; 2 Penn Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA; 3 Division of Cardiovascular Diseases, Albert Einstein Medical Center, Philadelphia, PA; 4 Division of Cardiac Surgery, University of Pennsylvania, Philadelphia, PA. Purpose: Right ventricular afterload consists of resistive and pulsatile com- ponents. Studies suggest pulmonary artery compliance (PAC) better approxi- mates total RV afterload due to increased pulsatile load in the context of elevated left atrial pressure. Reduced PAC is associated with poor prognosis in patients with pulmonary hypertension due to left heart failure. We evalu- ated measures of RV load to predict early right ventricular failure (RVF) and six-month mortality after continuous-flow LVAD (cf-LVAD). Methods: We identified 152 patients with complete pre-implant hemody- namics undergoing durable cf-LVAD since 2008 at our center. We measured PAC index [PACi = SV index /(PA S -PA D )] and resistive indices including PA diastolic-to-wedge gradient (DPG), transpulmonary gradient (TPG) and pul- monary vascular resistance (PVR). RVF was defined as the need for RVAD or inotropes for > 14 days. Logistic regression models were used to examine associations with RVF. Six-month survival, censored at transplant or VAD explant, was assessed using Kaplan-Meier and Cox proportional-hazards models. Results: Fifty-five patients (36%) developed RVF. In patients with and without RVF, there was no difference in mean DPG (3.3±4.1 vs 3.4±3.8 mmHg), TPG (11.8±5.9 vs 12.6±5.0 mmHg) or PVR (2.8±1.6 vs 3.2±1.7 WU), p>0.05 for all. In contrast, PACi was significantly lower in patients with RVF (0.9±0.5 vs 1.2±0.7 mL/m 2 /mmHg, p=0.006). PACi < median was associated with a two-fold increased risk of RVF (OR 2.1, 95%CI 1.1- 4.2, p = 0.029), which persisted after adjustment for CVP/PCWP, PVR and creatinine (OR 1.9, p = 0.04). Decreased PACi was associated with reduced 6-month survival (Figure). Conclusion: Decreased PACi, which reflects RV pulsatile load not captured by resistive indices, is associated with RVF and reduced early survival after cf-LVAD. Future studies are needed to assess the changes and relative contri- bution of the components of RV load on outcomes after LVAD implantation. ( 560) High Dose Antiplatelet Therapy Increases Early Bleeding Risk But Does Not Reduce Thrombotic Events in Patients With CF-LVADs O Saeed , 1 A. Shah, 1 C. Guerrero, 1 J. Nguyen, 1 S. Patel, 1 D. Sims, 1 J. Shin, 2 D. D’Alessandro, 3 D.J. Goldstein, 3 U. Jorde. 1 1 Cardiology, Albert Einstein College of Medicine Montefiore Medical Center, Bronx, NY; 2 Medicine, Results: All 5 patients were men and their mean age was 31.5 ± 1.8 years and the median time since their Mustard operation was 30 years (range 28 to 32 years). All patients had sternal closure on POD 1 and 2 patients required additional reoperation for bleeding. One patient required temporary support of the non-systemic ventricle. The mean duration of LVAD support was 284 ± 177 days; 3 patients underwent heart transplant and 2 died on days 502 and 34. The two deaths were due to progressive heart failure and pump throm- bosis. Comorbidities, anatomy, and mediastinal scarring did not preclude implantation and heart failure symptoms improved in all patients. Conclusion: With the increased prevalence of late post-Mustard heart failure, bridge to transplant with an LVAD may be a suitable treatment option for patients who are severely ill. ( 558) Reduced Continuous-Flow LVAD Speed Does Not Decrease von Willebrand Factor Degradation J. Kang , 1 D.M. Zhang, 1 D.J. Restle, 1 F. Kallel, 2 M.A. Acker, 1 P. Atluri, 1 C.R. Bartoli. 1 1 Cardiovascular Surgery, University of Pennsylvania, Philadelphia, PA; 2 Thoratec Corporation, Pleasanton, CA. Purpose: Bleeding is the most frequent complication of left ventricular assist device (LVAD) support. Evidence suggests that supraphysiologic shear stress from the LVAD and von Willebrand factor (vWF) play major roles. To manage bleeding, it has been proposed that decreased LVAD speeds may reduce shear stress within the LVAD and thereby reduce vWF degradation. However, there is little data to support this practice. In an LVAD mock circulatory loop, we tested the hypothesis that decreased LVAD speed reduces vWF degradation. Methods: Whole blood was obtained from LVAD patients (n=8) and from normal humans (n=16). The relationship between LVAD speed and vWF degradation was investigated in a continuous-flow LVAD mock circulatory loop. Units of donor human blood were exposed for 12 hours to 10,000 or 8,600 rpm (n=8/group) with a HeartMate II. vWF multimers and 11 vWF degradation fragments from LVAD patients and from the mock loop experiments were characterized with electrophoresis and immunoblotting. Student’s t-tests were performed across groups. Results: The LVAD mock loop produced the same profile of vWF degrada- tion fragments as patients with an LVAD. Blood circulated through the mock loop at 10,000 and at 8,600 rpm demonstrated a similar profile of decreased large vWF multimers and increased vWF degradation fragments (Figure). vWF degradation at 10,000 rpm and 8,600 rpm were quantitatively similar and were not statistically different (p=NS) for any degradation fragment. Conclusion: A decrease in LVAD speed did not reduce vWF degradation. For the first time, these data suggest that the clinical practice of decreasing LVAD speed during bleeding events may not reduce vWF degradation.