A key role for nuclear cardiac imaging in evaluating and managing patients with heart failure.

Congestive heart failure (CHF, HF) is a major health problem in the United States and much of the western world. More than 6 million Americans over age 20 have HF, with 1/5 people over 40 likely to develop HF sometime during their lives. Despite significant advancements in evaluation and management, the death rate remains high, with about 50% of HF patients dying in 5 years, and HF mentioned as a contributing factor in 1/9 death certificates. A variety of methods are used to assess patients with HF, including standard clinical techniques, i.e., history, physical examination, and laboratory measurements; a variety of non-invasive imaging procedures that include chest x-ray, echocardiography, equilibrium radionuclide angiography (ERNA), myocardial perfusion imaging with ECG-gated SPECT, cardiac CT methods, cardiac magnetic resonance imaging, and invasive procedures such as right and left heart catheterization, and coronary angiography. These methods diagnose HF, determine a likely etiology, classify its severity, identify additional contributing factors, and guide patient management in terms of remedying reversible causes, improving symptoms and patient well-being, and preventing additional adverse events ranging from frequent recurrent HF hospitalizations to dangerous cardiac arrhythmias to death. Recent American College of Cardiology Foundation/American Heart Association (ACCF/AHA) Heart Failure guidelines recommend comprehensive pharmacologic regimens, and describe when advanced mechanical device therapies such as biventricular pacemakers for cardiac resynchronization therapy (CRT), left ventricular assist devices (LVAD), and implantable cardiac defibrillators (ICD) should be considered, as well as when cardiac transplantation is the preferred option. Nevertheless, much remains unclear regarding the approach to patients with HF, a condition expected to increase in prevalence in coming years as the population ages. In particular, many of the beneficial advanced mechanical device therapies are costly and have risks. It is important to wisely select which patients should receive them. An issue of particular focus is who should get an ICD. Based on several multicenter, prospective randomized clinical trials, the ACCF/AHA HF guidelines assign a Class IA recommendation for implantation of an ICD as primary prevention of sudden cardiac death (SCD) in patients with New York Heart Association (NYHA) Class II-III symptoms and a left ventricular ejection fraction (LVEF) B35%. At the same time, while trials report significant reductions in mortality with ICDs, the absolute decrease in death is relatively small, from about 5.6% to 7.2%, with 11 to 14 patients needing to receive an ICD to save 1 life. There are risks associated with an ICD, including a 4% postprocedural complication rate, infections, device malfunction, worsened quality of life, psychiatric problems, and life style restrictions. ICDs are expensive, about $28,000 per device, not including ICD follow-up costs. Thus, current methods for choosing which patients receive an ICD have limitations, and using LVEF as a major deciding parameter appears flawed. A key way to identify patients who are best managed with advanced mechanical therapies such as an ICD, and/or who should be referred for cardiac transplant, is effective risk stratification, better if one can adjust predicted outcomes for clinical status changes, including when a device is added. Using databases from multiple large HF studies, survival scores have been developed incorporating combinations of clinical variables. One such model, the Seattle Heart Failure Model (SHFM), uses routinely collected demographic, imaging, laboratory, and therapeutic parameters to generate a From the Division of Nuclear Medicine, Department of Radiology, Division of Cardiology, Department of Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY. Reprint requests: Mark I. Travin, MD, FASNC, Division of Nuclear Medicine, Department of Radiology, Montefiore Medical Center, Albert Einstein College of Medicine, 111 E. 210th Street, Bronx, NY 10467-2490; mtravin@attglobal.net. J Nucl Cardiol 2012;19:879–82. 1071-3581/$34.00 Copyright 2012 American Society of Nuclear Cardiology. doi:10.1007/s12350-012-9615-9