Ischaemic risk and bleeding risk in acute coronary syndrome: still inseparable

This editorial refers to ‘Growth differentiation factor-15 level predicts major bleeding and cardiovascular events in patients with acute coronary syndromes: results from the PLATO study’†, by E. Hagström et al. on page 1325 The implementation of an invasive management strategy and the use of more potent antiplatelet and anticoagulant therapies have reduced the risk of recurrent ischaemic events in acute coronary syndrome (ACS), but are associated with bleeding complications.1 In a recent cohort of >120 000 ACS patients treated at 360 US hospitals, ∼1 out of 10 patients experienced a major bleeding event.2 Major bleeding has important implications in terms of prognosis, outcomes, and costs.3,4 Prevention of bleeding, while maintaining effective protection against ischaemic events, is therefore an important treatment goal in ACS. European Society of Cardiology (ESC) guidelines encourage clinicians to manage patients based on their individual risks of bleeding and recurrent ischaemic events. Guidelines provide specific recommendations for patients deemed at high or low risk of bleeding, for example regarding the duration of dual antiplatelet therapy or the choice of parenteral and oral anticoagulants.5,6 Unfortunately, we do not really know how to assess bleeding risk in individual patients. Several demographic and clinical variables are associated with the risk of bleeding, and risk scores have been developed to estimate bleeding risk in ACS. However, the ability of these scores to discriminate patients at different risks of bleeding is only modest,7 and the usefulness of bleeding risk scores to guide patient management remains uncertain. While the guidelines encourage us to weigh ischaemic vs. bleeding risks in individual patients, many risk factors for bleeding are also associated with recurrent ischaemic events. With our current tools, ischaemic risk and bleeding risk appear inseparable. For example, renal function, haemodynamic variables, and signs of heart failure on admission are key components of the GRACE (Global Registry of Acute Coronary Events) score, which predicts mortality and recurrent myocardial infarction, and the CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC/AHA Guidelines) bleeding risk score. Consequently, both scores predict ischaemic and bleeding events equally well.8