EDITORIAL Fractional flow reserve in acute coronary syndromes

raphy in guidingmanagement to optimize outcomes in non-ST-segment elevation myocardial infarction: the British Heart Foundation FAMOUS-NSTEMI randomized trial’, by J. Layland et al., on page doi:10.1093/eurheartj/ehu338 Little doubt exists about the outcome benefit of an invasive strategy in patients with an acute coronary syndrome (ACS).1 Yet, once the revascularization is performed, the treatment strategy of patients ad-mitted with an ACS is not always as straightforward in daily clinical practice as indicated in guidelines.2 The reasons for this are at least three-fold. First, a sizable proportion of patients admitted for an ACS have multiple stenoses on the angiogram.3 Based on the clinical history, the electrocardiogram (ECG), and the angiogram, it is (usually) easy to identify the stenosis responsible for the acute clinical syn-drome, but not to decide whether the non-culprit stenose