Current status of cardiovascular gene therapy

Gene transfer for the therapeutic modulation of cardiovascular diseases is an expanding area of gene therapy. During the last decade several approaches have been designed for the treatment of hyperlipidemias, post-angioplasty restenosis, hypertension, and heart failure, and for protection of vascular by-pass grafts and promotion of therapeutic angiogenesis. Adenoviruses (Ads) and adeno-associated viruses (AAVs) are currently the most efficient vectors for delivering therapeutic genes into the cardiovascular system. Gene transfer using local gene delivery techniques have been shown to be superior to less-targeted intra-arterial or intra-venous applications. To date, no gene therapy drugs have been approved for clinical use in cardiovascular applications. In preclinical studies of therapeutic angiogenesis, various growth factors such as vascular endothelial growth factors (VEGFs) and fibroblast growth factors (FGFs), have shown positive results. Gene therapy also appears to have potential clinical applications in improving the patency of vascular grafts and in treating heart failure. Post-angioplasty restenosis, hypertension, and hyperlipidemias (excluding homozygotic familial hypercholesterolemia) can usually be managed satisfactorily by conventional approaches, and are therefore less favored areas for gene therapy. The development of technologies that can ensure long-term, targeted, and regulated gene transfer, and a careful selection of target patient populations, will be very important for the progress of cardiovascular gene therapy in clinical applications.