339: Sudden cardiac death after heart transplant: Insights from the cardiac transplant research database

diffuser blade shapes but with the same hemolysis were tested for discrepancies with regard to platelet activation and functional capacity in-vitro. Four times, 0.5 L of human blood from 4 different subjects was used in 2 identical test loops (0.25 L in each loop) and was pumped under identical flow conditions (4 L per min against 80 mmHg) over a period of 4 hours. Blood samples were tested before the start of the pump and after 4 hours. Results: There was no difference between the pumps with regard to hemolysis. The ability of the platelets to bind to fibrinogen differed by 65%, expression of CD 62 by 25% and of CD 63 by 27%, the amount of platelet micro-particles by 22%. Among the functional capacity, after stimulation of the PAR-1 receptor of the platelets with 25 M (100 M) thrombin receptor activating peptide (TRAP) the difference was 63% (41%). Stimulation with 5 M ADP showed a difference of 48%. The ability of the platelets to bind to fibrinogen after stimulation with TRAP and ADP was more significantly pronounced (TRAP, 33%; ADP, 43%). Furthermore, the TRAP-induced expression of granulophysin and P-selectin was 53% and 32% different. No changes could be observed with regard of the binding of anti-vWF-FITC, thrombospondin-1-FITC, and annexin V to platelets. Conclusions: There was a huge difference between the pumps with regard to the state of platelet activation and functional capacity despite of the same hemolysis. Thus, a low hemolysis is not predictive for a low rate of thromboembolic events. Board Member; Berlin Heart.