One in eight people who were hospitalised with Covid-19 between May 2020 and March 2021 were later diagnosed with myocarditis, or heart inflammation, according to major new research into the clinical long-term effects of the virus.
The largest study of its kind to date, which followed 159 patients for one year after they were hospitalised with Covid-19, also found that inflammation across the body and damage to the other organs, such as the kidneys, was also common.
In addition, the study looked at why some patients suffer long-term ill health after hospitalisation with Covid-19. Until now it has been speculated that previous underlying health conditions may be linked to the severity of post-Covid long-term effects. However, research suggests that it is the severity of the Covid-19 infection itself which is most closely correlated to the severity of a patient's long-Covid symptoms, rather than pre-existing health problems.
Read more: Thousands of people incorrectly offered Covid booster vaccines by Welsh Government
The CISCO-19 (Cardiac Imaging in SARS Coronavirus disease-19) study, which aimed to increase understanding of the coronavirus pandemic, followed patients in real time after hospitalisation with Covid-19 and compared their health to those in a control group of individuals of similar age, sex and medical background.
Assessments included blood tests, and CT and MRI scans of multiple organs, including the heart, kidneys and lungs, as well as measuring patients' own opinions on their own ongoing health via questionnaires. Clinical outcomes including survival, hospital readmission and referral to outpatient clinics were also assessed.
Researchers said exercise capacity and health-related quality of life were markedly impaired initially after discharge from hospital and remained reduced one to two months after discharge – this was especially the case in patients with heart inflammation. During a period of 450 days after discharge from hospital, one in seven patients died or were readmitted to hospital, and two in three patients required NHS outpatient care.
Patients were given questionnaires on the same day they underwent blood tests and scans, before they had been given clinical results, in order to gain a true understanding of how they were feeling post-hospitalisation. From these questionnaires, having been hospitalised with Covid-19 was associated with a worse health-related quality of life as well as with anxiety and depression.
Professor Colin Berry, principle investigator of the CISCO-19 study and professor of Cardiology and Imaging at the University of Glasgow, said: "Covid-19 is a multi-system disease, and our study shows that injury on the heart, lungs and kidneys can be seen after initial hospitalisation in scans and blood tests. These results bridge a vital knowledge gap between our current understanding of post-Covid-19 syndromes, such as long Covid, and objective evidence of ongoing disease.
"One of the most important findings of the CISCO study is that it is the severity of a patient's Covid-19 infection – not their underlying health conditions – that is most closely correlated with the severity of any ongoing health outcomes post discharge. We found that previously healthy patients, without any underlying health conditions, were suffering with severe health outcomes, including myocarditis, post hospitalisation.
"The reasons for this are unclear, but it may be that a healthy person who is hospitalised with Covid-19 is likely to have a worse Covid infection than someone with underlying health conditions who is hospitalised. More work needs to be done here to understand the risks, and also on how we can better support patients who have ongoing health outcomes after being hospitalised with Covid-19."
Long Covid has been found to predominately affect women, the study suggests. CISCO found that female sex was associated with myocarditis, which in turn was linked with lower mental and physical wellbeing. Researchers believe these findings provide some answers that could explain the physical limitations experienced by some female patients post Covid-19 hospitalisation.
Considering clinical translation into healthcare, the results highlight the need for focused use of medical tests, new therapy development and rehabilitation. The results also highlight the importance of avoiding severe Covid-19 such as by vaccination.
Professor Julie Brittenden, director of research and innovation at NHS Greater Glasgow and Clyde (NHSGGC), said: "NHSGGC is pleased to have played an important role in this study, which has further enhanced our understanding of the long-term effects of Covid-19 in patients who required to be hospitalised.
"I would like to thank all of our patients who have taken part in this study, as well as the wider research teams who continue to work to improve knowledge, develop treatment options and improve outcomes of patients with Covid-19 ”
Professor David Crossman, Chief Scientist (Health) for Scotland at the time the study was funded, said: "This study provides important insight into the longer-term effects of Covid-19 infection, and will help inform approaches to treatment going forward. The Chief Scientist Office is pleased to have funded this research as part of the £5m Rapid Research in COVID-19 programme.”
The CISCO study focuses on people hospitalised with Covid-19, however other studies looking at community covid infections – infections not severe enough to result in hospitalisation – have reported more encouraging data on long-term health recovery. Patients in this study were enrolled during the first and second waves of the pandemic, until March 2021, and as a result they were mainly unvaccinated.
Among the patients enrolled in the study, risk factors for heart disease were common, including overweight or obesity, high blood pressure and pre-diabetes or diabetes.
Staff from several hospitals in the west of Scotland supported the project, including the Queen Elizabeth University Hospital and the Royal Infirmary in Glasgow, the Royal Alexandra Hospital in Paisley, Hairmyres Hospital in NHS Lanarkshire and the NHS Golden Jubilee in Clydebank.
Dr Kenneth Mangion, clinical lecturer in cardiology at the University of Glasgow, and co-senior author, said: "We are grateful for the support from the Chief Scientist Office, NHS GG&C, NHS R&D. We are also grateful to all co-investigators, clinicians, research nursing staff, scientists, lab technicians radiographers, who have all worked together to help deliver this project."
The study, ‘Multisystem, cardio-renal investigation of post-covid illness’ is published in Nature Medicine. The work was funded by the Scottish Government’s Chief Scientist Office, and supported by the British Heart Foundation (BHF) as part of the University of Glasgow BHF Centre of Excellence.
