Molecular Imaging of Left Ventricular Remodeling

Every year nearly 1 million Americans with myocardial infarction suffer from acute coronary syndromes. Despite advances in reperfusion therapy, these molecular events may often lead to ventricular adverse remodeling resulting in the heart failure. This observation became a driving force to develop noninvasive imaging strategies to evaluate remodeling using concepts of molecular imaging. As such, cardiovascular imaging plays an important role in shifting the paradigm from the disease treatment to early diagnosis, prognostication, and stratification, which has a tremendous potential to alleviate socioeconomic and health care costs associated with the treatment of heart failure patients. This review is intended to be a brief overview of recent nuclear imaging techniques and applications to assess molecular events associated with the process of left ventricular (LV) remodeling following myocardial infarction (MI). The specific approaches presented here will include imaging of perfusion, viability, metabolism, cardiac neuroreceptors, angiogenesis, proteases activity, and renin-angiotensin-aldosterone system activation. We will first describe basic concepts of molecular imaging, then we will provide an overview of recent advances in molecular imaging technology, and finally we will report current nuclear imaging strategies in assessment of LV remodeling. The emphasis will be put on radiotracer-based modalities including single photon emission computed tomography (SPECT) and positron emission tomography (PET) techniques, although other clinical imaging modalities will be also briefly discussed. We expect that in near future these targeted imaging approaches will complement standard physiological parameters and will play a crucial role in post-MI patients' stratification and development of individual therapy regimes.