Evaluation of the percutaneous intramyocardial injection for local myocardial treatment

Therapeutic angiogenesis requires the induction of new blood vessel formati on for the treatment of peripheral vascular and coronary artery disease, Ef ficacious application of this new therapy requires optimizing multiple fact ors, including the therapeutic agent, dosing, frequency of administration, and delivery modality. In this study, a helical needle drug infusion cathet er was applied for optimal application of percutaneous intramyocardial deli very (PIMD). (125)Iodine-labeled albumin was injected by PIMD into the left ventricle myocardium in eight swine. After 1 hr, PIMD resulted in a high c oncentration of radiolabel at the treatment site; 16.4% +/- 2.1% of deliver ed and 81.4% +/- 2.6% of the total cardiac activity was concentrated at the site of delivery. The depth of needle penetration correlated with the myoc ardial retention of delivered protein. The myocardial retention of radiolab el in animals with shallow injections was 10.1% +/- 0.8%, compared to 18.9% +/- 3.3% retention after deep injections. The specific activity at the tre atment site (radioactive counts per gram of tissue) was 115 +/- 36, 226 +/- 55, and 47 +/- 10 times higher compared to liver, lung, and kidney, respec tively. Continuous coronary sinus and aortic blood sampling indicates that within 15 min following intramyocardial injection, a significant amount of nonretained protein is found within the coronary sinus, This study defines some of the parameters that can affect optimal application of PIMD and demo nstrates that PIMD is a safe and efficient method for local drug delivery, (C) 2001 Wiley-Liss, Inc.