Elevated Leukocyte Count and Platelet-Derived Thrombogenicity Measured Using the Total Thrombus-Formation Analysis System in Patients with ST-Segment Elevation Myocardial Infarction

Aims: High platelet-derived thrombogenicity during the acute phase of ST -segment elevation myocardial infarction (STEMI) is associated with poor outcomes; however, the associated factors remain unclear. This study aimed to examine whether acute inflammatory response after STEMI affects platelet-derived thrombogenicity. Methods: This retrospective observational single-center study included 150 patients with STEMI who were assessed for platelet-derived thrombogenicity during the acute phase. Platelet-derived thrombogenicity was assessed using the area under the flow-pressure curve for platelet chip (PL-AUC), which was measured using the total thrombus-formation analysis system (T-TAS). The peak leukocyte count was evaluated as an acute inflammatory response after STEMI. The patients were divided into two groups: the highest quartile of the peak leukocyte count and the other three quartiles combined. Results: Patients with a high peak leukocyte count (>15,222/mm(3); n=37) had a higher PL-AUC upon admission (420 [386-457] vs. 385 [292-428], p=0.0018), higher PL-AUC during primary percutaneous coronary intervention (PPCI) (155 [76-229] vs. 96 [29-170], p=0.0065), a higher peak creatine kinase level (4200 +/- 2486 vs. 2373 +/- 1997,p<0.0001), and higher PL-AUC 2 weeks after STEMI (119 [61-197] vs. 88 [46-122],p=0.048) than those with a low peak leukocyte count (<= 15,222/mm(3); n=113). The peak leukocyte count after STEMI positively correlated with PL-AUC during primary PPCI (r=0.37,p<0.0001). A multivariable regression analysis showed the peak leukocyte count to be an independent factor for PL-AUC during PPCI (beta=0.26, p=0.0065). Conclusions: An elevated leukocyte count is associated with high T-TAS-based platelet-derived thrombogenicity during the acute phase of STEMI.