Background: This study tested the hypothesis that in the acute phase of myocardial infarction (MI), the circulating level of soluble CD40 ligand (sCD40L), an index of platelet activation, is predictive of angiographic morphologic features that indicate high-burden thrombus formation (HBTF) in the infarct-related artery (IRA).
Methods and results: This prospective study included 162 consecutive patients: 64 with HBTF and 98 with low-burden thrombus formation (LBTF). All patients had a Killip's classification<or=3 ST-segment elevation acute myocardial infarction (AMI) of onset<12 h who were undergoing primary percutaneous coronary intervention (PCI). Blood samples for measurement of the circulating levels of sCD4L and high-sensitivity C-reactive protein (hs-CRP) and white blood cell (WBC) count were collected before PCI. The circulating levels of sCD40L and hs-CRP, and the WBC count were also evaluated in 20 normal control subjects. Blood was aspirated by export suction catheter from the intracoronary artery (ICA) in 49 HBTF patients. The WBC count, and the circulating levels of hs-CRP and sCD40L were significantly higher in the HBTF and LBTF groups than in the normal control subjects (all p<0.005). Additionally, the circulating levels of sCD40L and the WBC count were substantially higher in the HBTF than in the LBTF patients (all p<0.001). Furthermore, in HBTF patients the ICA had a significantly higher sCD40L level and WBC count compared with the values for the systemic circulation (all p<0.001). Multiple statistical analyses identified increased circulating level of sCD40L as the most independent predictor of HBTF in the IRA (p<0.0001).
Conclusions: The sCD40L level is the most independent predictor of angiographic morphologic features that indicate HBTF in the acute phase of MI.