New frontiers in cardiovascular polymeric controlled release

The regional nature of cardiovascular disease, whether in the heart itself or the arterial tree, is an appropriate focus for localized therapy using drug delivery implants. This is now possible through the use of controlled release implants which are formulated from drug-polymeric composites. These controlled release matrices have sustained drug administration properties, and thus far have been clinically useful in a cardiac pacemaker lead tip configuration, which elutes an antinflammatory steriod to enhance pacing electrode function. A number of experimental studies using cardiovascular controlled release implants have been carried out, and these have been concerned with preventing calcification of bioprosthetic heart valves, treating and preventing ventricular arrhythmias, and forestalling experimental heart transplant rejection. The future uses of controlled release implants will focus on the broad range of strategies including preventing coronary artery restenosis and gene therapy.