Trials of angiogenesis therapy in patients with ischemic heart disease

Abstract

After initial success in in vitro and in vivo studies showing tremendous potential of angiogenic therapy, therapeutic angiogenesis has been studied in humans with ischemic heart disease (IHD) not responding to conventional treatments. Vascular endothelial growth factor, fibroblast growth factor, and granulocyte colony stimulating factor are among the most commonly tested cytokines in human trials. Delivery as a protein or vector with gene encoding for specific protein have been tested in these trials. In addition, multitude of delivery routes ranging from direct intramyocardial transfer to intracoronary infusion to systemic administration via subcutaneous route have been tried. Clinical, radiographic, and angiographic parameters have been used to gauge the effect of these therapies in human trials. While promising results were attained in small phase I studies, these salutary results have not been replicated in large phase II and III studies. Multitude of variables including duration of exposure, type of vector, and need for co-factor influence the process of angiogenesis. Further studies accounting for these variables are needed to fully determine the potential of therapeutic angiogenesis in IHD.