Endothelial inflammation and thrombolysis resistance in acute myocardial infarction

Background: Despite recent refinements to thrombolysis for acute myocardial infarction, a significant minority of patients still fail to reperfuse. There is no reliable predictor of this state of ‘thrombolysis resistance’, but platelet and endothelial factors are believed to be important. Cell adhesion molecules are expressed by the endothelium when activated and their shed or soluble portion can be quantified in the peripheral serum, where they may be taken as a measure of endothelial activation. We sought to find a link between markers of endothelial inflammation at time of infarction and failure to reperfuse as measured by vessel occlusion at angiography. Methods: Patients presenting with their first acute myocardial infarction had levels of soluble adhesion molecules, C-reactive protein and monocyte chemotactic protein-1 measured prior to thrombolysis. An angiogram on day five after admission was performed to establish patency of the index vessel. Results: Levels of soluble vascular adhesion molecule-1 (sVCAM-1) taken prethrombolysis were significantly elevated compared to those with a patent vessel (620±90 vs. 418±28 ng/ml, P<0.03. The positive predictive value of sVCAM-1 for vessel patency was 88%. Conclusions: We found elevated serum levels of the adhesion molecule soluble vascular adhesion molecule-1 (sVCAM-1) at presentation in patients with acute myocardial infarction who did not respond to thrombolysis. Endothelial activation may be important in thrombolysis resistance.