Optimal management of acute coronary syndromes in the era of COVID-19

### Learning objectives The coronavirus pandemic (COVID-19) has had unprecedented impact on healthcare systems, including acute cardiology services.1 2 COVID-19 directly leads to cardiac complications in those patients with underlying heart disease or cardiac risk factors. COVID-19 indirectly impacts patients through the required change in healthcare resource allocation and the need for social distancing. A reduction in health-seeking behaviour3 4 reduced attendances for cardiac emergencies,5 6 and reduction in traditional chronic care will have implications that extend beyond the infective reach of the virus. Therefore, cardiovascular care during the pandemic should remain a priority to mitigate the significant morbidity and mortality from both the direct and indirect effects of COVID-19.7 As future coronavirus waves are anticipated, it is prescient to review its impact on the delivery of cardiovascular care, in particular the management of acute coronary syndromes (ACS). Early reports suggested a strong relationship between traditional cardiovascular risk factors and poor outcomes from COVID-19.8 9 COVID-19 related myocardial injury is evident in postmortems.10 Those with critical illness demonstrate elevation of troponin and B-type natriuretic peptide (BNP) levels and rising levels correlate to poorer clinical outcomes.11 12 The mechanisms of myocardial injury remain poorly understood but candidates may involve ACE2 expression within the myocardium and coronary vessels triggering local inflammation, hypercoagulopathy and thrombosis. Coronary thrombosis will cause ACS and localised ischaemia in the form a type I myocardial infarction (MI).11 Ischaemia may also result from respiratory failure and hypoxia; in the context of underlying coronary disease, …