Cardiopulmonary long-term impairment in patients 6 and 18 months post severe Covid-19 infection
Authors: Niebauer J H , Iscel A , Schedl S , Capelle C , Kahr M , Schamilow S , Badr-Eslam R , Lichtenauer M , Zoufaly A , Valenta R , Charwat-Resl S , Krestan C , Hitzl W , Wenisch C , Bonderman D 
Published: November 2023

Abstract

Background
Covid-19 infection affects the cardiopulmonary system in the acute as well as long-term phase. The aim of the present study was to deliver a comprehensive report of symptoms and possible long-term impairments 6 and 18 months after hospitalization for severe Covid-19 infection.

Methods
This prospective registry included patients after PCR-confirmed Covid-19 infection, who were treated as in-patients at our Covid-19 department. Follow-up approximately 6 months post discharge comprised a detailed patient history, clinical examination, transthoracic echocardiography, electrocardiogram, cardiac magnetic resonance imaging (cMRI), chest computed tomography (CT) scan, pulmonary function test (PFT), six-minute walk test (6MWT) and a comprehensive laboratory panel including brain natriuretic peptide and troponin T. At the time of the second follow-up visit at 18 months, patients who did not show any abnormalities during the first study visit or refused to return for a follow-up visit, were contacted by phone to inquire about the course of symptoms (n=42). In all other patients with abnormalities during the first study visit, blood testing, echocardiography and 6MWT were repeated. CT, cMRI and lung function test were only performed in case of pathological findings during the first study visit.

Results
Between July 2020 and April 2022 200 patients were recruited (91% general ward, 9% intensive care unit). Due to dropouts the second study visit was only performed in 149 patients. A comparison between the two study visits at 6 and 18 months post discharge showed the following results: Six months after discharge, 73% and 18 months after discharge 52% fulfilled the criteria for Long-Covid with fatigue being the most common symptom (figure 1). Echocardiography at 6 months post discharge showed a reduced left ventricular function in 8% (n=15), of which 80% returned to normal at 18 months (n=5, figure 2). Six months post discharge, cMRI revealed pericardial effusion in 17% (n=25) and resolved in 43% of the 7 patients who underwent a control cMRI. Signs of peri- or myocarditis were present in 5% of the patients (n=7) at 6 months and were resolved in all 4 patients in control studies. PFT detected reduced vital capacity in 11% of patients (n=17). Values improved in 50% and normalized in 10% of the 10 patients, who attended the second study visit. At 6 months, pulmonary CT scans identified post-infectious residues in 22% (n= 39), of which 24% showed full recovery. A predictor for persisting Long-Covid was the length of in-hospital stay (95% CI: 1.005 - 1.12, p=0.03) as an indicator for the severity of the initial disease course.

Conclusion
Comparing 6 to 18 months after severe Covid-19 infection, the prevalence of Long-Covid decreased over time, but a high symptom burden remains. Structural and functional abnormalities were less frequent compared to the portrayed symptoms, and it remains a challenge to substantiate the symptoms.SymptomsFunctional and Structural changes