The Essence of STRATEGY Is Choosing What Not to Do.

Abstract

> The essence of strategy is choosing what not to do. > > —Michael Porter, Harvard Economist Clinicians must evaluate on a daily basis patients with symptoms of possible coronary artery disease (CAD). Decades of progress in various technologies used for cardiovascular imaging have produced a wide array of choices, and consequently selecting the best test for a given patient has become increasingly complex. Anatomic techniques to evaluate for CAD include invasive coronary angiography (ICA) or coronary computed tomographic angiography (CTA). However, functional approaches evaluate the myocardial response to exercise or pharmacological stress, often together with imaging. When considering the available functional imaging tests, stress echocardiography and nuclear myocardial perfusion imaging are commonly available and well-established techniques. However, there are now emerging data that stress cardiac magnetic resonance imaging (CMR) may offer comparable, or in some cases superior, diagnostic accuracy.1 More recently, the CE-MARC 2 trial (Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease 2) suggested that CMR and nuclear myocardial perfusion imaging may decrease the rate of unnecessary ICA (defined as invasive angiography that results in nonobstructive or nonflow limiting disease) when compared with clinical evaluation using the NICE guideline (National Institute for Health and Care Excellence).2 Importantly, among patients randomized to the NICE guideline group, ≈35% underwent immediate ICA as directed by the guidelines. CE-MARC 2 also demonstrated a strategy of CMR was safe, as the event rate observed in this trial was extremely low and did not differ between the groups compared. These findings, together with others,3,4 suggest that in stable patients who do not have prior known CAD, noninvasive testing should be performed before invasive angiography. See Article by Pontone et al Aside from increasing the yield of detecting obstructive CAD on invasive angiography, there are many other important ways in which …