The v3-integrin is expressed in angiogenic vessels in response to hypoxia, and represents a potential novel target for imaging myocardial angiogenesis. This study evaluated the feasibility of non-invasively tracking hypoxia-induced v3-integrin activation within the myocardium as a marker of angiogenesis early after myocardial infarction. Acute myocardial infarction was produced by coronary artery occlusion in rodent and canine studies. A novel ¹¹¹In-labeled radiotracer targeted at the v3-integrin (¹¹¹In-RP748), was used to localize regions of hypoxia-induced angiogenesis early after infarct. In rodent studies, the specificity of ¹¹¹In-RP748 for v3-integrin was confirmed with a negative control compound (¹¹¹In-RP790) and regional uptake of these compounds correlated with ²⁰¹Tl perfusion and a ^99mTc-labeled nitroimidazole (BRU59-21), which was used as a quantitative marker of myocardial hypoxia. The ex vivo analysis demonstrated that only ¹¹¹In-RP748 was selectively retained in infarcted regions with reduced ²⁰¹Tl perfusion, and correlated with uptake of BRU59-21. In canine studies, myocardial uptake of ¹¹¹In-RP748 was assessed using in vivo SPECT, ex vivo planar imaging, and gamma well-counting of myocardial tissue, and correlated with ^99mTc-sestamibi perfusion. Dual-radiotracer in vivo SPECT imaging of ¹¹¹In-RP748 and ^99mTc-sestamibi provided visualization of ¹¹¹In-RP748 uptake within the infarct region, which was confirmed by ex vivo planar imaging of excised myocardial slices. Myocardial ¹¹¹In-RP748 retention was associated with histological evidence of v3-integrin activation/expression in infarct region. ¹¹¹In-RP748 imaging provides a novel non-invasive approach for evaluation of hypoxia-induced v3-integrin activation in myocardium early after infarction, and may prove useful for directing and evaluating angiogenic therapies in patients with ischemic heart disease.