Gene therapy approaches to cardiovascular disease.

The potential of enhanced cardiovascular function via gene therapy has aroused extensive interest. Both viral and nonviral vectors have shown promise in the realm of cardiovascular gene therapy. Modification of vectors or addition of further transgenes to the expression cassette has permitted targeted and regulated gene expression. The many potential targets of cardiovascular gene therapy can be considered under the following headings: vascular, congenital heart disease, and myocardial. Cardiac gene delivery may be to either the endothelium of either native coronary vessels or coronary artery bypass grafts, or to the myocardium. Myocardial gene delivery is possible either via direct myocardial injection or via the coronary vasculature. However, alteration of any cardiac cellular signaling pathway may have cardiotoxic effects. Thus, any genes that appear to cause enhanced cardiac function, must undergo extensive toxicity studies in animals before similar experiments are performed in human subjects. The techniques described may be utilized in the future to deliver various genes targeted to combat many different disease processes, in different animal models, and ultimately to provide feasible gene therapy approaches to human cardiovascular disease.