Nuclear cardiology: Its role in cost effective care

The incidence and prevalence of cardiovascular diseases (CVDs), of which coronary artery disease (CAD) account for the vast majority of cases, are increasing tremendously in every part of the world, regardless of the level of development. CVDs are now the leading cause of death worldwide, resulting on more than five million deaths per year in the developing world. A great deal of effort has been devoted to reducing the incidence of severe CAD, as evidenced by the slight decline in morbidity and mortality in developed countries. However, this has not been seen in the developing world. There has also been much emphasis on primary prevention in CAD, and the concept of 'imaging for prevention' has recently been advocated. The diagnostic and prognostic value of myocardial perfusion imaging (MPI) in CAD is very well established. Nuclear techniques not only provide perfusion and functional data which aid the management decision, they also provide non-perfusion data (for example, lung to heart ratio, transient ischaemic dilation of the left ventricle (TID), right ventricular uptake and myocardial stunning), which can also aid in decision making. Although MPI has many advantages, it has its limitation in that it cannot detect early stage coronary disease, and may miss detection of multivessel disease, resulting in balanced ischaemia. Single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) remains an accepted standard for the detection and quantification of significant myocardial ischaemia and has been shown to be a strong prognostic indicator of the risk for adverse cardiac events. Recently, other techniques, including cardiac computed tomography angiography has been promoted vigorously in the detection of coronary disease. The use of coronary calcium score for the early detection of atherosclerotic disease has been well established and it can provide powerful prognostic information, leading to modifications in the management of CAD, which would not otherwise have been achieved if the early disease remained undetected. This publication presents a comprehensive overview of CVDs as a public health problem in developing countries, the relative role of nuclear cardiology methods within a scenario of unprecedented technology advances, and the evidence behind appropriateness recommendations. The potential expanding role of non-invasive functional imaging through the transition from diagnosis of obstructive CAD to defining the global burden of CVDs is also discussed, as well as the need for thorough training, education, and quality in nuclear cardiology practice. This report will be of interest for all medical practitioners involved in the management of CAD, including internists, cardiologists, and nuclear medicine physicians, as well as hospital administrators and health care stakeholders.