Additional applications of approved radiopharmaceuticals for nuclear cardiology

Radionuclide studies of the heart and blood vessels provide information for patient management as well as an understanding of patient-specific pathophysiology. The information gleaned from these studies may be enhanced by using more than a single tracer or by making multiple measurements with a single radiopharmaceutical (similar to measuring thallium redistribution). After more than 40 years of clinical use (Valenta et al., Curr Cardiol Rep 15:344, 2013), the examination with the most clinical value continues to be myocardial perfusion imaging for detection of myocardial ischemia and scar. New techniques, however, are available to expand the application of approved radiopharmaceuticals in patients with heart disease. This manuscript will present recent developments in two areas: (1) Evaluation of mitochondrial function or sympathetic innervation in patients with heart failure (HF). In this case, radionuclide techniques provide data that adds significant predictive value to functional parameters, such as left ventricular ejection fraction, to identify HF patients at high risk of clinical events. (2) Direct evaluation of focal vascular inflammation, microcalcification and calcification in patients with dyslipidemia. Localization and characterization of the intensity of inflammation, or early phases of calcification in atheroma, may permit more personalized therapy than can be obtained from traditional measurements of lipid levels in patients with dyslipidemia. Ultimately, characterizing atheroma, especially in the coronary and carotid arteries, may be the imaging approach of choice to permit effective pharmacologic therapy geared at reducing the incidence and severity of clinical events.