ABSTRACT
Direct transfer of genes holds promise for the sustained delivery of therapeutic proteins to treat cardiovascular diseases. This can be accomplished by several approaches, including use of adenoviral vectors and naked plasmid DNA vectors.1 Animal studies have shown the feasibility of enhancing collateral perfusion and function by direct intramyocardial delivery of angiogenic factors injected into the myocardium.2 There is a theoretical advantage of direct intramyocardial injection of the therapeutic agent versus its infusion into the coronary arteries. During intracoronary injection, a significant amount of the drug may not be taken up by the myocardium and therefore will be delivered to systemic organs. With direct intramyocardial injection, it is more likely that less of the drug will be delivered systemically. This mode of delivery would therefore: (1) limit exposure to non-target organs; (2) minimize the likelihood of systemic toxicity and adverse hemodynamic effects; (3) enable high intramyocardial concentration while limiting total dose; and (4) allow precise localization to ischemic and periischemic myocardial regions.
