Damage to the heart found in more than half of COVID-19 patients discharged from hospital
Around half of those hospitalised with COVID-19 and who show raised levels of a protein called troponin have suffered some damage to their heart, according to a new study which included patients at two trusts in North Thames.
Patients from the Royal Free London NHS Trust and University College London NHS Foundation Trust (UCLH) are among those who took part in the study, supported by CRN North Thames, which looked at the impact of raised levels of troponin on the heart in those who had been in hospital with COVID-19.
The study showed around 50% of patients who have been hospitalised with COVID-19 and who show raised levels of troponin had some injury to their hearts. The injury was detected by a magnetic resonance imaging (MRI) scan at least a month after discharge, according to new findings published in the European Heart Journal.
The study of 148 patients from the Royal Free London, UCLH and Imperial College Healthcare NHS Trust is the largest study to date to investigate convalescing COVID-19 patients who had raised troponin levels, indicating a possible problem with the heart.
Heart injury includes inflammation of the heart muscle (myocarditis), scarring or death of heart tissue (infarction), restricted blood supply to the heart (ischaemia) and combinations of all three.
Troponin is released into the blood when the heart muscle is injured. Increased levels can occur when an artery becomes blocked or there is inflammation of the heart. Many patients who are hospitalised with COVID-19 have raised troponin levels during the critical illness phase, when the body mounts an exaggerated immune response to the infection. Troponin levels were elevated in all the patients in this study. Those patients were then followed up with MRI scans of the heart after discharge in order to understand the causes and extent of the damage.
Professor Marianna Fontana, director of the UCL cardiac magnetic resonance unit at the Royal Free Hospital, who led the research, said: “Raised troponin levels are associated with worse outcomes in COVID-19 patients. Patients with severe COVID-19 disease often have pre-existing heart-related health problems including diabetes, raised blood pressure and obesity. During severe COVID-19 infection, however, the heart may also be directly affected. Unpicking how the heart can become damaged is difficult, but MRI scans of the heart can identify different patterns of injury, which may enable us to make more accurate diagnoses and to target treatments more effectively.”
Dr Rob Bell, Senior Research Fellow at UCL and a co-author of the paper, said: “What this study represents is a first step. It tells us that an elevated troponin is not a meaningless result – in over half of the people who have an elevated troponin, there is something not right about the heart – be that coronary disease or inflammation of the heart.
“How these observations impact upon people’s survival with COVID is yet to be determined but it does highlight a need to pay much more attention to the heart in this disease and to apply known treatments that may benefit patient outcomes.”
The researchers investigated COVID-19 patients discharged up until June 2020. Patients who had abnormal troponin levels were offered an MRI scan of the heart after discharge and were compared with those from a control group of patients who had not had COVID-19, as well as from 40 healthy volunteers.
The recovering COVID-19 patients had been very ill; all required hospitalisation and all had troponin elevation, with around one in three having been on a ventilator in the intensive care unit.
The findings of the study are limited by the nature of patient selection and included only those who survived coronavirus infection requiring hospital admission.