Around 50 per cent of patients hospitalised with severe COVID-19 and raised troponin levels have myocardial injury, the results of a study published in the European Heart Journal suggest.
The study included 148 patients with severe COVID-19 infection who required hospital admission (32% requiring ventilatory support) and had troponin elevation discharged from six hospitals in three NHS Trusts - Royal Free London, Imperial College and University College London (UCL).
Participants underwent convalescent multi-parametric cardiovascular magnetic resonance at median 68 days.
Left ventricular (LV) function was found to be normal in 89 per cent (ejection fraction 67%±11%). However, late gadolinium enhancement and/or ischaemia was found in 54 per cent. This comprised myocarditis-like scar in 26 per cent, infarction and/or ischaemia in 22 per cent and dual pathology in 6 per cent.
Myocarditis-like injury was limited to three or less myocardial segments in 88 per cent of cases with no associated LV dysfunction. Of these, 30 per cent had active myocarditis.
Myocardial infarction was found in 19 per cent and inducible ischaemia occurred in 26 per cent of those undergoing stress perfusion, including seven participants with both infarction and ischaemia. Of patients with ischaemic injury pattern, 66 per cent had no past history of coronary disease. There was no evidence of diffuse fibrosis or oedema in the remote myocardium.
The authors concluded that during convalescence after severe COVID-19 infection with troponin elevation, myocarditis-like injury can be encountered, with limited extent and minimal functional consequence.
“Whether these observed findings represent pre-existing clinically silent disease or de novo COVID-19-related changes remain undetermined,” they said.
Commenting on the findings, study author, Professor Marianna Fontana from UCL 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.”
