COVID-19: Detecting persistent lung damage through structured aftercare

People infected with COVID-19 often suffer long-term lung function impairment, but preliminary CovILD study results found improvement over time for many patients.

The priority is to treat symptoms and lung damage early

People infected with COVID-19 often suffer from long-term impairment of lung function, but the preliminary results of the CovILD study found that many people with COVID-19 improved over time.1

The aim of the CovILD study was to identify the frequency and pattern of lung abnormalities in medium to critical COVID-19 patients after recovery. All test subjects lived in a "hot spot" area in Tyrol, Austria. They were treated at the Internal Medicine Department of the Medical University of Innsbruck, the St. Vincent Hospital, Zams, or the cardio-pulmonary rehabilitation center in M√ľnster (Rehabilitationszentrum), Austria. At the ERS virtual meeting, Dr. Sabina Sahanic (Medical University of Innsbruck) presented data from the first 86 test subjects taken between 29 April and 9 June 2020. 

Follow-up examinations after 6, 12, and 24 weeks

Follow-up examinations were scheduled for 6, 12, and 24 weeks after discharge from the hospital. During these patient visits, clinical examinations, laboratory tests, lung function tests, computer tomographies, and echocardiograms were carried out. The average age of the 86 patients included in this presentation was 61 years, and 65% of them were male. Almost half of the test subjects were current or former smokers and 65% were overweight or obese. Eighteen (21%) were treated in an intensive care unit, 16 (19%) had received invasive mechanical ventilation and the average length of stay in the hospital was 13 days.

A total of 56 patients (65%) showed persistent symptoms at the time of their examination after 6 weeks; the most common symptom in 40 subjects (47%) was dyspnea, followed by coughing (13 patients, 15%). By the time the visit took place after 12 weeks, the shortness of breath had improved but was still present in 31 of the subjects (39%), but the percentage of patients with coughing did not change.

Lung function parameters improved between visits at 6 and 12 weeks

Lung function parameters (FEV1, FVC, and DLCO) improved between visits after 6 and 12 weeks. After 6 weeks, 20 subjects (23%) showed FEV1 <80% of the normal value. After 12 weeks this improved in 18 patients (21%). After 6 weeks, 24 subjects (28%) had FVC <80% of the normal value, which improved to 16 patients (19%) after 12 weeks. And after 6 weeks, 28 participants (33%) showed DLCO <80% of the normal value, which improved to 19 patients (22%) after 12 weeks. 

Pathological CT findings were present in 74 subjects (88%) after 6 weeks and in 48 participants (56%) after 12 weeks. Severe pathological CT findings were more frequent in patients treated in intensive care units. The most important damage patterns at the follow-up examination were ground-glass opacity and reticulations. "Fortunately, we found no signs of progressive pulmonary fibrosis in our test group," said Dr. Sahanic. 

CT could indicate lung damage that was not detected by lung function tests

After 6 weeks, the echocardiograms showed that 48 subjects (58.5%) had left ventricular diastolic dysfunction. After 6 weeks, more than half of the patients had at least one persistent symptom, mainly shortness of breath and coughing, and the CT scans still showed lung damage in 88% of the participants. However, by the next visit 12 weeks after discharge, symptoms had improved and lung damage was reduced to 56%. At the time of the presentation, the results are still being evaluated after 24 weeks.

"The results of this study show the importance of introducing structured follow-up care for patients with severe COVID-19 infection. Importantly, CT in this patient group showed lung damage that was not detected by lung function tests. Knowing how patients are affected by coronavirus in the long term would allow symptoms and lung damage to be treated much earlier, which could have a significant impact on further medical recommendations and advice," Dr. Sahanic concluded.

1. Sahanic, S. et al Persisting pulmonary impairment following severe SARS-CoV-2 infection, preliminary results from the CovILD study Abstract OA4143, ERS International Virtual Congress 2020, 7-9 Sept.