Lung sequelae, lingering symptoms remain 1 year after COVID-19 hospitalization

Many survivors of severe to critical COVID-19 had lung sequelae and lingering symptoms lasting up to 1 year after their infection, according to study results published in European Respiratory Journal.

However, as more months passed after being discharged from the hospital, patients did show improvements in other aspects, according to researchers.

“Most patients with prolonged follow-up had progressive lung-function, exercise-capacity and radiological improvements, with greater progress made during the first 6 months post-hospital discharge than thereafter,” Frédéric Schlemmer, MD, PhD, pulmonologist at Assistance Publique-Hôspitaux de Paris (APHP) at Hôspitaux Universitaires Henri-Mondor, and colleagues wrote.

“Pertinently, we further showed that not only critically-ill patients — including a notable proportion of patients managed with standard oxygen — were followed until [12 months], suggesting that early post-discharge assessment is relevant to identify, among the whole spectrum of severe to critical COVID-19 survivors, those requiring longer surveillance,” Schlemmer and colleagues added.

In a prospective, multicenter cohort study, Schlemmer and colleagues analyzed 485 adults (median age, 60.7 years; 73% men) hospitalized with severe to critical COVID-19 to understand their short- to long-term trajectories of lung function recovery and radiological abnormalities after being discharged from the hospital.

Researchers categorized patients according to the WHO clinical progression scale, with 173 patients receiving standard oxygen (WHO 5), 96 receiving noninvasive ventilatory support without further invasive mechanical ventilation (WHO 6), and 216 patients requiring invasive mechanical ventilation for more than 48 hours (WHO 7-9).

Researchers evaluated the total cohort 3 months after hospital discharge. They followed up with 293 (60.4%) patients at 6 months and 170 (35.1%) at 12 months due to dyspnea, weak lung function (FVC less than 80% predicted and/or diffusing capacity of the lungs for carbon monoxide [DLCO] less than 70% predicted) and/or significant radiological sequelae found during the 3-month and/or 6-month assessment.

At the 3-month follow-up, researchers found that nearly two-thirds of patients reported dyspnea-on-exertion and 52.3% reported fatigue, with only the latter differing in frequency between WHO groups.

For those with extended follow-up, dyspnea remained a common complaint for more than 50% of patients, and fatigue persisted for more than one-third of patients.

Researchers found a similar prevalence of anxiety and depression among WHO groups at 3 months, and these rates stayed the same over follow-up periods.

At 3 months, 34% of patients had a restrictive lung defect and 70.2% had impaired DLCO. Also, among 422 patients who underwent CT scans at 3 months, 55.9% had significant radiological sequelae, of which 91.5% had ground-glass opacities and 81.4% had reticulations, whereas 24.6% of patients showed minimum residual signs of COVID-19-pneumonia and 19.4% had normal results.

Looking at each patient’s last available scan, researchers found that 41.3% of patients had a significant COVID-19-attributed residual lung abnormality on their last scan, including 24.6% of patients at 3 months, 40.2% at 6 months and 70.7% at 12 months.

In terms of respiratory function trajectories, researchers observed a 4.1-point increase in DLCO at 6 months and a 6.5-point increase at 12 months. For FVC% predicted, there was a 4.3-point increase at 6 months and a 5.9 point-increase at 12 months.

Multivariate analyses showed that impaired lung function was independently linked to underlying chronic respiratory disease, immunodeficiency, a COVID-19-related lung abnormality extent of more than 50% on CT scans during acute illness, corticosteroid use or invasive mechanical ventilation for more than 14 days. On the other hand, improved functional recovery was linked to male sex and obesity.

“Although most of the participants globally recovered, high percentages had radiological and functional sequelae and residual symptoms throughout follow-up, all of which might have affected their health-related quality of life,” Schlemmer and colleagues wrote. “Our findings also highlighted the burdens of post-hospital monitoring for such patients and their clinicians, and provided additional clues for how to organize that follow-up after severe to critical disease.”