NPR and PR platelets demonstrate variable but overall similar aggregation. (A) Under light transmission aggregometry induced by thrombin, aggregation of NPR and PR platelets had similar tracing morphology and no difference in slope or AUC across experimental days. Platelets from trials 1 and 2 were tested and representative curves of day 3 and day 7 platelets (trial 1) are shown. Both slope and AUC for replicates were compared using the t test and P < .05 was considered significant. (B) Under impedance aggregometry induced by collagen or thrombin analog, whereas both NPR (orange) and PR (blue) platelets (trial 3) demonstrated aggregation, NPR platelets exhibited a more robust response. Data are shown as impedance over time normalized to the baseline and as a calculated AUC. The red arrows indicate the time the agonist was administered. CI, confidence interval.