Effect of DDAVP on intracellular free Ca²⁺concentration after simultaneous platelet activation with convulxin and thrombin. (A) Intracellular Ca²⁺ course in a representative patient before DDAVP administration (P1, baseline; P2, <30 seconds; P3, 1 minute; P4, 2 minutes; P5, 4 minutes; P6, 6 minutes after simultaneous platelet activation with convulxin and thrombin). (B) Summary of intracellular Ca²⁺ course in 15 patients at baseline (median fold-increase and 95% CIs). (C) Intracellular Ca²⁺ after simultaneous platelet activation with convulxin and thrombin in a representative patient after DDAVP administration. (D) Relative intracellular Ca²⁺ course after DDAVP compared with baseline (median fold-change and 95% CIs) in patients with enhanced COAT platelet generation (median increase, 29%; n = 11) and those without (n = 4). CVX, convulxin; Thr, thrombin.