Overall strategies of Myocardial Gene Transfer

The overarching concept of cardiac gene therapy is simple: replace or remove a disease-causing gene at the level of the myocardium, thereby eliminating a fundamental incipient for a given condition. In practice, there is an array of selection criteria and obstacles to consider. For any gene therapy to be successful, the gene(s) of interest must not only be delivered but also expressed at adequate concentrations in the target tissue bed. The tools used to accomplish this gene transfer are known as vectors. The ideal vector manifests tissue selectivity, low immunogenicity, adequate packaging capacity, and a durable level of gene expression. To date, current vector options incorporate some, but not all of these attributes. Vectors can be described in two broad categories: viral (gene transduction) and non-viral (transfection). Following selection, the vector of choice may be delivered to the myocardium through a variety of techniques over a spectrum of invasiveness and specificity. There is no single optimal combination of the above factors, rather, it is necessary to understand the appropriate applications and limitations of each.