Detecting the Effects of Angiogenic Therapy: How Do We Measure Efficacy?

This review examines methods for detecting the effects of angiogenic interventions on myocardial blood flow and left ventricular function. Animal-based methods of measuring myocardial blood flow are presented, as are other methods for detecting angiogenesis in animal models. Clinically feasible end points, including perfusion imaging with radionuclide techniques, positron emission tomography, myocardial contrast echocardiography, magnetic resonance perfusion imaging, and electron-beam computed tomography with iodinated contrast, are then discussed. The strengths and weaknesses of each technique in relation to measurement of the efficacy of angiogenic interventions are analyzed. Indirect methods for detecting enhanced blood flow by regional or global left ventricular function are discussed, with attention to the reproducibility of serial measurements obtained with these approaches. Specific recommendations for efficacy and effectiveness end points in angiogenic trials are provided.