Background: Ischemic/reperfusion (I/R) injury substantially effects the outcome of myocardial infarction (MI). Current reperfusion therapy does not sufficiently prevent injury caused by microvascular thrombo-inflammation. Coagulation proteases mediate inflammation via protease activated receptors. FXa induced thrombin generation is the key step in the coagulation cascade. We hypothesize that inhibition of FXa by rivaroxaban attenuates I/R injury after MI. Methods: Male WT c57BL/6 mice (age 8-9 weeks, n=8 per group) underwent surgical ligation of the left anterior descending coronary artery 7 days prior to experimentation. Next, the ligature was tightened for 1h to induce ischemia and loosened either at 4h (early), or at 4 weeks (late), to allow reperfusion. The intervention consisted of 2 rivaroxaban (1.6 mg/kg) i.v.-injections or placebo (0.9%NaCl) after 15min of ischemia and 5min of reperfusion. In the early model. the area at risk (AAR) was visualized through Evans blue and differentiated from the area of infarction (AOI) through triphenyl tetrazolium chloride staining. Plasma cardiovascular markers were quantified using Luminex Multiplex. In the late model, LVEF was measured 10min pre-ischemia and 4 weeks’ post-reperfusion utilizing echocardiography. Results: The rivaroxaban treatment group showed signs of diminished myocardial damage as indicated by reduced median AOI/AAR (41%[IQR34-48] vs. control 62%[IQR52-67] p<0.001). This was supported by a better preserved LVEF after 4 weeks of reperfusion (25%[IQR19-31] vs. control (16%[IQR12-21]). Although not significantly different, plasma E-Selectin, PECAM-1, PAI-1, proMMP9, and thrombomodulin showed a trend to increased levels upon treatment with rivaroxaban. Conclusion: FXa inhibition by rivaroxaban significantly reduces myocardial I/R injury in mice and may provide long term preservation of LVEF. Raised cardiovascular markers suggest increased tissue remodeling and phenotypical alteration of endothelial cells after rivaroxaban treatment. These results suggest that coagulation proteases (i.e. FXa) play a relevant role in I/R injury during MI, most likely through activation of protease activated receptors.