Intramyocardial Gene Therapy Directed to Hibernating Heart Muscle Using a Combination of Electromechanical Mapping and Positron Emission Tomography

Abstract

Cardiac gene transfer for the treatment of ischemic diseases has suffered from low gene transfer efficiency and inability to target treatment genes to the ischemic myocardium. A combined method has been developed based on electromechanical mapping and radiowater PET imaging to target gene therapy to viable but ischemic and hibernating areas of the myocardium. Electromechanical NOGA mapping produces three-dimensional images of myocardium with both an electric activity map and a myocardial contractility map. These have been converted to 17-segment 2D bull's-eye maps, which were superimposed onto PET radiowater perfusion imaging maps of the myocardium. This technique was applied in a Phase I/IIa clinical trial to target gene therapy for refractory angina patients. It was found that by combining electromechanical map with PET imaging, targeting of gene therapy to hibernating ischemic myocardium can be significantly improved. Here, the methods for the identification of viable, ischemic, and hibernating myocardium for gene transfer are described, and examples of treated refractory angina patients who have benefited from the improved gene transfer method to the ischemic myocardium are presented.