In Vivo Left Ventricular Assist Induced Coagulation Derangements: Comparison of Sarns-3M and St. Jude Medical Circuits

An in vitro comparison of centrifugal pumping systems manufactured by Sarns-3M and St. Jude Medical revealed a difference in blood cell derangement. The purpose of this study was to compare in vivo the effects of 96 hr of left ventricular assist (LVA) on indexes of coagulopathy, hemolysis, and complement activation. Two groups of calves (eachn = 5) were instrumented with identical left atrial to thoracic aorta centrifugal pumping circuits using either Sarns-3M or St. Jude centrifugal pumps. Laboratory evaluations were performed pre-assist and at 1, 4, 24, 48, 72, and 96 hr during LVA. Platelet counts dropped significantly by 24 hr (Sarns-3M28%; St. Jude30%); no significant change in function was noted. Activated clotting time increased slightly (p > 0.05). Prothrombin time increased at 4 and 24 hr of LVA, returning to baseline by 96 hr (p < 0.05). Activated partial thromboplastin time increased with the St. Jude device from 24 to 96 hr on LVA (p < 0.05); the increase with the Sarns-3M device never reached significance. No significant changes in lactate dehydrogenase or plasma free hemoglobin were detected. Complement fraction C5a rose by 1 hr of LVA (p < 0.05), peaking at 4 hr and returning to baseline by 96 hr with both pumps. No significant difference was detected between pump groups for any of the parameters. It was concluded that 1) 96 hr Sams-3M and St. Jude LVA caused coagulation derangement in calves, 2) neither pump demonstrated an advantage regarding coagulation and complement parameters, 3) hemolysis observed with the Sarns-3M pump in vitro was not evidenced in vivo, and 4) in vitro evidenced centrifugal pump differences may not be realized in vivo. ASAIO Journal 1997; 43-M414-M417.