Severe cases of Covid-19 have been associated with a ‘cytokine storm’, where the virus ‘Spike’ protein causes the immune system to go into overdrive and produces a surge of damaging molecules called cytokines. Now, by using routine chest CT scans, researchers at the University of Oxford have developed a Covid-19 ‘signature’ using machine learning. The ‘signature’ detects biological red flags in the fat surrounding the blood vessels in the chest to measure the level of cytokine-driven vascular inflammation in people infected with the virus. The team applied the Covid-19 signature to CT chest scans of 435 people admitted to hospitals in Oxford, Leicester and Bath, and compared the degree of inflammation and risk of death in people with and without Covid-19.
For patients admitted to hospital, the level of cytokine-driven inflammation in the blood vessels was much higher in those with Covid-19, and even greater in patients infected by the B.1.1.7 or ‘alpha’ variant first identified in the UK. Those with a high level of vascular inflammation were up to eight times more likely to die in hospital, and were most likely to respond well to the anti-inflammatory drug Dexamethasone. Covid-19 patients with high vascular inflammation treated with Dexamethasone had a 6-fold reduction in risk of dying compared to Covid-19 patients who were not given the drug.
By using this tool to obtain an inflammation score, Covid-19 patients found to have a lot of inflammation in their blood vessels, and therefore increased risk of death, could potentially be given anti-inflammatory drugs to reduce their risk and help their long-term recovery. Clinical trials are now looking into the effectiveness of this approach.
Now, the researchers will continue to look at the impact of coronavirus variants as they emerge. They say that their technology may have immense power to easily track the long-term cardiovascular effects of Covid-19 and quickly respond to future viruses.
Professor Charalambos Antoniades, Professor of Cardiovascular Medicine and BHF Senior Clinical Research Fellow at the Radcliffe Department of Medicine, University of Oxford, said: “We have built an incredibly adaptable AI platform that tracks vascular disease by decoding information from blood vessel images obtained routinely during hospital admission, and integrating it with a large RNA bioresource from human tissue biopsies. By simply adding in one extra step to the routine care of people admitted to hospital with Covid-19 who already have a CT scan, we can now detect patients at high risk of life-threatening complications and could potentially tailor their treatment to aid long-term recovery. But the benefits don’t stop there. We know that this exaggerated immune response to the virus can also cause abnormal blood clotting, and so we are developing this AI platform to specifically identify Covid-19 patients who are most at risk of having a future heart attack or stroke. We can also pivot our platform with ease to develop a new scanning ‘signature’ to better understand future viruses and diseases that take hold of our population.”
Professor James Leiper, Associate Medical Director at the British Heart Foundation, said: “Over the past year we have supported our scientists to direct their expertise to help the global effort in understanding Covid-19. This research clearly demonstrates that Covid-19 is a powerful virus that can wreak havoc on our circulatory system, and that different variants are associated with different levels of risk. There are still a lot of unknowns relating to how the virus can impact our health in the long term, but this AI tool could ultimately help to save lives.”
This research is one of the six research programmes chosen as UK Flagship Projects, all of which aim to improve care for people with heart and circulatory disease suffering from Covid-19. The initiative builds on a pre-existing partnership between the BHF and the National Institute for Health Research (NIHR), and provides a new framework for the rapid set-up and delivery of urgent, high impact Covid-19 research projects across the UK.
Source: British Heart Foundation