Prior simvastatin treatment is associated with reduced thrombin generation and platelet activation in patients with acute ST-segment elevation myocardial infarction

Background: It has been reported that statin therapy produces additional effects including impaired activation of blood coagulation. It is not clear whether statins can affect hemostasis in patients with acute coronary syndrome. The aim of this study was to investigate the effect of prior statin treatment on thrombin generation and platelet activation in patients with ST-segment elevation myocardial infarction (STEMI). Methods: We studied 53 consecutive STEMI patients admitted within 12 hours of pain onset, including 19 treated with simvastatin (40 mg/d) (simvastatin group) at least one month prior to STEMI, and 34 not receiving any statins (no-statin group) on admission. Thrombin-antithrombin (TAT) complexes generation and soluble CD40 ligand (sCD40L) release were determined in 60-second blood samples collected at the site of microvascular injury. Results: There were no significant intergroup differences with respect to clinical and laboratory variables, including plasma TAT and sCD40L levels, except lower total cholesterol and low-density lipoprotein cholesterol in the simvastatin group. The mean maximum rate of TAT generation was 47.5% lower (p=0.0002) and sCD40L release 33.3% lower (p=0.0006) in the simvastatin group. Total amounts of TAT (p < 0.0001) and sCD40L (p=0.002) collected within 5 minutes of bleeding were lower in simvastatin-pretreated patients. By multivariate regression analysis, variables describing local TAT and sCD40L profiles in the whole group were independently associated with simvastatin pretreatment (p < 0.0001), but not with cholesterol, platelet count or troponin levels. Conclusions: Prior simvastatin use is associated with lower thrombin generation and platelet activation following vascular injury in the early phase of STEMI. (C) 2009 Elsevier Ltd. All rights reserved.