LAUSR

Due to the variable and multifaceted clinical presentation, the prevalence of stable coronary artery disease (CAD) is difficult to determine. Populationbased studies have reported an estimated prevalence of 4-7% among 45-64 year olds and 10-15% among 65-84 year olds. Despite trends that suggest a decreasing mortality, the prevalence of stable CAD does not appear to have decreased. The accurate and timely diagnosis of CAD remains challenging. Clinical history and physical examination may be misleading or unyielding, and the traditional stress electrocardiogram (ECG) may lack sensitivity thereby missing out on a substantial proportion of patients with clinically significant CAD. Sekhri and colleagues reported that every third patient suffering CAD death or myocardial infarction having had clinical work-up for CAD in the preceding 5 years had been erroneously cleared from a suspected CAD diagnosis. On the other hand, the prognosis of stable CAD may vary from excellent to very poor based on the severity of disease and extent of jeopardized myocardium. Over the years, randomized trials have demonstrated that medical therapy, including platelet inhibitors, cholesterol-lowering drugs, and inhibitors of the renin-angiotensin-aldosterone system and lifestyle changes are the most effective treatments to affect long-term outcomes while revascularization should be reserved for patients at immediate high risk of cardiovascular events or refractory to medical treatment. The global importance of appropriate CAD diagnosis and treatment has prompted international cardiological societies, such as the European Society of Cardiology (ESC), the American College of Cardiology (ACC), and the American Heart Association (AHA) to issue recommendations and update them periodically based on new evidence. This issue of the Journal of Nuclear Cardiology features a comparison between the most recent European (EU) and US guidelines dealing with stable CAD. Both guidelines have emphasized over the last years the increasing role that imaging technologies play in (i) the initial work-up of suspected CAD, (ii) the prognostic assessment of established CAD and its impact on treatment strategies, and (iii) the follow-up of CAD patients after treatment. While both EU and US guidelines agree on the majority of issues, minor differences of opinion may still be observed and are most likely related to differences between EU and US local practice, medico-legal and socio-economic systems, and different weighing of the published evidence. Furthermore, in the field of medical imaging, evidence from large randomized trials is scarce, therefore, the appropriate use of technologies is largely based on interpretation and comparison of diagnostic studies and longitudinal cohorts. Moreover, it should be mentioned, that both guideline documents date back to 2013 and 2012, respectively. The field of medical imaging is rapidly growing and several new studies have been published in the meantime which are expected to modify the recommendations in future issues of these documents. The purpose of the present editorial is to work out the most important differences in recommendations and to highlight those with potential relevance for clinical practice. Reprint requests: Oliver Gaemperli, MD, FESC, University Heart Center Zurich, Ramistrasse 100, 8091, Zurich, Switzerland; [email protected] J Nucl Cardiol 2018;25:521–5. 1071-3581/$34.00 Copyright 2017 American Society of Nuclear Cardiology.