Platelet transfusion induces transfusion-associated circulatory overload in rats with myocardial infarction

BACKGROUND: Transfusion-associated circulatory overload (TACO) accounts for 35% of transfusion-related fatalities. Previous pre-clinical studies explored plasma and red blood cell transfusion in TACO, but the effect of platelets remains unexplored. Platelet transfusions have the highest rate of adverse reactions and are associated with increased mortality in TACO patients. We aimed to determine whether platelet transfusion induces circulatory overload compared to crystalloids and whether it causes a more severe phenotype than plasma in a TACO rat model of myocardial infarction (MI). METHODS: A validated TACO model in anemic Wistar rats with MI was used. Animals received platelets (n = 11), plasma (n = 10), or Ringer's lactate (n = 11). Pulmonary capillary pressure was assessed via left-ventricular end-diastolic pressure (LVEDP). The primary outcome was the change in LVEDP (ΔLVEDP) following transfusion. Secondary outcomes included pulmonary wet/dry weight ratio, oxygen tension or partial pressure of oxygen (PaO(2))/fraction of inspired oxygen (FiO(2)) ratio, and circulating biomarkers. RESULTS: ΔLVEDP following platelet transfusion (10.4 ± 4.6 mmHg) was significantly greater than Ringer's lactate (0.9 ± 1.4 mmHg; p < .001), but similar to plasma (13.0 ± 7.7 mmHg; p > .5). Pulmonary wet/dry weight ratios were comparable across groups (p > .5). At termination, PaO(2)/FiO(2) ratio was significantly lower after platelet transfusion (372 ± 48) compared to Ringer's Lactate (447 ± 79; p < .05). N-terminal prohormone of brain natriuretic peptide (NT-proBNP) did not differ between groups at termination (p > .1). However, NT-proBNP significantly increased from baseline (50 ± 24 pg/mL) to termination (177 ± 86 pg/mL) across all groups (p < .001). DISCUSSION: Platelet transfusion induces circulatory overload in a TACO rat model with heart failure when compared to crystalloids, showing a trend toward reduced oxygenation compared to plasma transfusion. Further investigation is needed to determine the pathophysiological mechanisms.