Heart damage found in 50% of COVID-19 patients discharged from hospital

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In a new study, researchers found around 50% of patients hospitalized with severe COVID-19 and who show raised levels of a protein called troponin have damage to their hearts.

Damage includes inflammation of the heart muscle (myocarditis), scarring or death of heart tissue (infarction), restricted blood supply to the heart (ischemia) and combinations of all three.

The injury was detected by magnetic resonance imaging (MRI) scans at least a month after discharge.

The research was conducted by a team at University College London and elsewhere.

Troponin is released into the blood when the heart muscle is injured. Raised levels can occur when an artery becomes blocked or there is inflammation of the heart.

Many patients who are hospitalized with COVID-19 have raised troponin levels during the critical illness phase when the body mounts an exaggerated immune response to the infection.

In the study, the team tested 148 patients from six acute hospitals in London.

These COVID-19 patients had raised troponin levels indicating a possible problem with the heart.

The team found troponin levels were elevated in all the patients who were then followed up with MRI scans of the heart after discharge in order to understand the causes and extent of the damage.

The function of the heart’s left ventricle, the chamber that is responsible for pumping oxygenated blood to all parts of the body, was normal in 89% of the 148 patients but scarring or injury to the heart muscle was present in 80 patients (54%).

The pattern of tissue scarring or injury originated from inflammation in 39 patients (26%), ischaemic heart disease, which includes infarction or ischemia, in 32 patients (22%), or both in nine patients (6%). Twelve patients (8%) appeared to have ongoing heart inflammation.

The team says raised troponin levels are linked to 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 doctors to make more accurate diagnoses and target treatments more effectively.

The findings help doctors to find ways of preventing the injury in the first place and detecting the consequences of injury during convalescence may identify patients who would benefit from specific supporting drug treatments to protect heart function over time.

One author of the study is Professor Marianna Fontana.

The study is published in European Heart Journal.

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