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196: POTENTIAL IMPACT OF RED BLOOD CELL STORAGE LESION ON CARDIAC ELECTROPHYSIOLOGY

Introduction/Hypothesis: Transfusion of red blood cells (RBCs) remains a vital intervention for millions of critically ill adults and children. As RBCs are stored over time, changes known as the “storage lesion” may occur and contribute to transfusion complications. The impact of the RBC storage lesion on cardiomyocyte electrophysiology is largely unknown. This study aimed to determine the impact of RBC storage age on the electrophysiology of human-induced pluripotent stem cell derived cardiomyocytes (hipSC-CM). Methods: HipSC-CM were cultured on a multi-electrode array (MEA) plate to measure fluctuations in extracellular field potential (FP), spike amplitude and beat period generated from spontaneously beating hipSC-CM. Three units of RBCs were obtained from the American Red Cross and aliquoted into small volume blood bags (Volume 100ml per SVBB). The SVBB were subsequently refrigerated and the supernatant (SSRBCs) removed at day 7, day 18 and day 35 postdonor collection. SSRBCs samples were added to the hipSC-CM maintaining media to stimulate an RBC transfusion. HipSC-CM electrophysiology was analyzed at baseline and post application of SSRBCs. Results: In the current study, beating rate remained stable in both control (1.3±0.24s) and day 7 (1.4±0.31s), but slowed immediately after application of day 18 (2.0±0.65s, p<0.01) and day 35 (1.8±0.44s,p<0.01) SSRBCs. Slowed beating rate, akin to bradycardia, persisted for the 1 hour treatment but recovered after removal of SSRBCs. Spike amplitude, an indicator of Na+ channel current, was also significantly decreased in hipSCCM co-cultured with either 10% or 17% SSRBCs, when isolated from the “older” RBC units (p<0.001). FP duration, which allows for measurement of repolarization time, was not significantly different between the “fresh” vs. “older” units of RBCs. Conclusions: Many studies agree that the RBC storage lesion occurs as RBC units are stored over time. However, there is disagreement on the clinical impact of the storage lesion and whether “old” blood presents an increased risk to patients compared to “fresh” blood. In the current cardiac electrophysiology model, the depolarization spike amplitude and spontaneous beat rate were both affected. Further studies will be utilized to identify the direct effect of “fresh” vs. “old” blood.