Findings indicate potential ways to identify individuals at higher or lower risk.
A recent study conducted by investigators from the University College London and Imperial College London has found that around 50% of patients who were hospitalized with a severe form of the coronavirus disease 2019 (COVID-19) and had raised levels of troponin had damage to their hearts. Results from the study were published in the European Heart Journal.
Troponin, a complex of regulatory proteins, is released when damage has been done to the heart muscle. Levels increase when arteries become blocked or there is inflammation in the heart. Higher levels of troponin has been observed in COVID-19 patients during a critical stage of illness, as the body is mounting an exaggerated immune response to fight off the infection.
"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,” Marianna Fontana, a lead researcher on the study said. “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."
Investigators used magnetic resonance imaging (MRI) to analyze scans of 148 patients from 6 acute hospitals in London discharged up until June of 2020. The patients all had abnormal levels of troponin and had their scans compared to those of 40 healthy volunteers. The investigators found that for those with higher levels of troponin, their hearts showed inflammation to the heart muscle, scarring or death of tissue and a restricted supply of blood to the heart.
Of the 148 patients, 89% had normal oxygenated blood pumping to all parts of the body, but 54% had scarring or injury to the heart muscle. 39 patients had tissue scarring or injury stemming from inflammation, 32 patients showed ischemic heart disease and 9 patients had both. Additionally, 12 of the patients appeared to have ongoing issues with heart inflammation.
"These findings give us two opportunities: firstly, to find ways of preventing the injury in the first place, and from some of the patterns we have seen, blood clotting may be playing a role, for which we have potential treatments,” Fontana said. “Secondly, detecting the consequences of injury during convalescence may identify subjects who would benefit from specific supporting drug treatments to protect heart function over time."