At the time of their first follow-up visit after hospital discharge, CT scans still showed lung damage in 88% of patients. However, by the time of their next visit 12 weeks after discharge, symptoms had improved and lung damage was reduced to 56%.
COVID-19 patients can suffer long-term lung and heart damage but, for many, this tends to improve over time, according to the first, prospective follow-up of patients infected with the coronavirus, presented at the European Respiratory Society International Congress.
Researchers in Austria recruited coronavirus patients to their study who were hospitalized at the University Clinic of Internal Medicine in Innsbruck, the St Vinzenz Hospital in Zams or the cardio-pulmonary rehabilitation centre in Münster, Austria.
The patients are evaluated at six, 12 and 24 weeks after their discharge from hospital. During these visits, clinical examinations, laboratory tests, analysis of the amounts of oxygen and carbon dioxide in arterial blood, lung function tests, computed tomography (CT) scans and echocardiograms were carried out.
At the time of their first visit, more than half of the patients had at least one persistent symptom, predominantly breathlessness and coughing, and CT scans still showed lung damage in 88% of patients. However, by the time of their next visit 12 weeks after discharge, the symptoms had improved and lung damage was reduced to 56%. At this stage, it is too early to have results from the evaluations at 24 weeks.
“The bad news is that people show lung impairment from COVID-19 weeks after discharge; the good news is that the impairment tends to ameliorate over time, which suggests the lungs have a mechanism for repairing themselves,” said Dr Sabina Sahanic, who is a clinical PhD student at the University Clinic in Innsbruck and part of the team that carried out the study, which includes Associate Professor Ivan Tancevski, Professor Judith Löffler-Ragg and Dr Thomas Sonnweber in Innsbruck.
The average age of the 86 patients included in this presentation was 61 and 65% of them were male. Nearly half of them were current or former smokers and 65% of hospitalised COVID-19 patients were overweight or obese. Eighteen (21%) had been in an intensive care unit (ICU), 16 (19%) had had invasive mechanical ventilation, and the average length of stay in hospital was 13 days.
A total of 56 patients (65%) showed persistent symptoms at the time of their six-week visit; breathlessness (dyspnoea) was the most common symptom (40 patients, 47%), followed by coughing (13 patients, 15%). By the 12-week visit, breathlessness had improved and was present in 31 patients (39%); however, 13 patients (15%) were still coughing
Tests of lung function included FEV1 (the amount of air that can be expelled forcibly in one second), FVC (the total volume of air expelled forcibly), and DLCO (a test to measure how well oxygen passes from the lungs into the blood). These measurements also improved between the visits at six and 12 weeks. At six weeks, 20 patients (23%) showed FEV1 as less than 80% of normal, improving to 18 patients (21%) at 12 weeks, 24 patients (28%) showed FVC as less than 80% of normal, improving to 16 patients (19%) at 12 weeks, and 28 patients (33%) showed DLCO as less than 80% of normal, improving to 19 patients (22%) at 12 weeks.
The CT scans showed that the score that defines the severity of overall lung damage decreased from eight points at six weeks to four points at twelve weeks. Damage from inflammation and fluid in the lungs caused by the coronavirus, which shows up on CT scans as white patches known as ‘ground glass’, also improved; it was present in 74 patients (88%) at six weeks and 48 patients (56%) at 12 weeks.
At the six-week visit, the echocardiograms showed that 48 patients (58.5%) had dysfunction of the left ventricle of the heart at the point when it is relaxing and dilating (diastole). Biological indicators of heart damage, blood clots and inflammation were all significantly elevated.
Dr Sahanic said: “We do not believe left ventricular diastolic dysfunction is specific to COVID-19, but more a sign of severity of the disease in general. Fortunately, in the Innsbruck cohort, we did not observe any severe coronavirus-associated heart dysfunction in the post-acute phase. The diastolic dysfunction that we observed also tended to improve with time.”
She concluded: “The findings from this study show the importance of implementing structured follow-up care for patients with severe COVID-19 infection. Importantly, CT unveiled lung damage in this patient group that was not identified by lung function tests. Knowing how patients have been affected long-term by the coronavirus might enable symptoms and lung damage to be treated much earlier and might have a significant impact on further medical recommendations and advice.”