Manganese-Enhanced Magnetic Resonance Imaging of MyOcardial injuRY in COVID 19 (MEMORY- COVID)

COVID-19 Pandemic This is the first major pandemic the modern world has faced since the Spanish Flu in 1918, with a profound impact on all aspects of society as we know it. Governments worldwide have put in place emergency plans to help tackle and reduce the rapid spread of the infection, with social isolation being implemented by most to varying degrees. As expected, healthcare systems are facing unprecedented challenges and real-time re-structuring. As well as focusing on the identification and management of critically unwell COVID-19 patients, healthcare organisations have the responsibility of protecting the public from infection and to continue the treatment of non COVID-19 related conditions. This has resulted in a complete reorganisation in how we deliver care, prioritising safety and infection control measures. In reality, this means cancelling routine clinics and procedures and has the potential to have a great impact on patient care.

COVID-19 The pool of evidence regarding this novel strain of coronavirus and the associated infection is growing as the condition unfolds. The current estimated case fatality rate varies between 1.4%-2.3%, with higher rates in the elderly, certain ethnic groups and those with co-morbidities. The largest case series from the Chinese Centre of Disease Control and Prevention reported 72,314 case records from suspected and confirmed cases. The clinical severity was reported as mild in 81.4%, severe in 13.9% and critical in 4.7%. Although clinical presentation of COVID-19 can be variable, most commonly symptoms resemble those of other viral respiratory tract infections: fever, cough, dyspnoea, myalgia and fatigue. In severe cases, COVID-19 is associated with bilateral pneumonia, acute respiratory distress syndrome (ARDS), and septic and cardiogenic shock, with higher mortality and morbidity seen in elderly and comorbid patients.

Patients with known cardiovascular risk factors or established cardiac problems are at higher risk of contracting severe acute respiratory syndrome- coronavirus-2 (SARS-CoV-2), and this confers a worse prognosis in COVID- 19 infection. It is difficult to establish the true link between COVID-19 and prevalence of cardiovascular complications due to the lack of testing in community and the cohort of patients who are admitted to secondary care, who are likely to be older and have co-morbidities and therefore are more likely to have pre-existing cardiac conditions and develop new cardiovascular complications.

COVID-19: Myocardial Injury Myocardial injury with necrosis can occur with and without overt ischaemia from acute myocardial infarction and is defined as an elevated plasma cardiac troponin concentration above the 99th centile. There are different mechanisms underlying acute myocardial injury; with ischaemia from an acute coronary syndrome and prolonged myocardial oxygen demand/supply imbalance being the most familiar. It is well recognised that an acute myocardial injury may occur in the absence of ischaemia due to a variety of cardiac and non-cardiac causes. Furthermore, this can be seen in critically unwell patients of varying aetiology and is a marker of poor prognosis.

Therefore determining the underlying mechanism is vital in guiding clinical care and improving outcomes. Myocardial injury is increasingly recognised in COVID-19 patients and, as anticipated, it correlates with severe cases and poor outcomes.5 In a cohort of 191 patients with confirmed COVID-19, plasma cardiac troponin concentrations were elevated in non survivors compared to survivors: 46% (23/50) compared to 1% (1/95) mortality.