Long-term cardiopulmonary effects after Covid-19 infection
Authors: Niebauer J H , Binder- Rodriguez C , Iscel A , Klenk S , Badr-Eslam R , Cadjo S , Kahr M , Hoffman S , Reiter-Malqvist S , Boeck R , Wenisch C , Krestan C , Lichtenauer M , Bonderman D 
Published: October 2021

Abstract

Introduction
The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic of 2020 has an influence on people's lives worldwide, impacting global health and putting pressure on health care systems. Multiple studies have described acute effects of the Covid-19 infection on the heart, but little is known about the long-term cardiac effects and complications after recovery. The aim of this analysis was to deliver a comprehensive report of symptoms and long-term impairment after Covid-19 infection.

Methods
This study was a prospective, multicenter registry study. Patients with verified COVID-19 infection, who were treated at our dedicated COVID hospital (Klinik Favoriten), have been included in this study. In all patients, testing was performed approximately 6 months post discharge. During each study visit the following tests and investigations were performed: detailed patient history and clinical examination, transthoracic echocardiography, electrocardiography, cardiac magnetic resonance imaging (MRI), pulmonary computed tomography (CT) scan, lung function test, spiroergometry and six-minute walk test (6MWT), and a comprehensive list of laboratory parameters including cardiac bio markers such as brain natriuretic peptide (NTpro BNP) and troponin T.

Results
In this interim analysis of an ongoing trial, the first 65 patients are presented. Baseline values are shown in table 1: 34 (59%) were male and the median age was 48.5 years (36.4–59.3). 86% of all patients included so far had an only mild to moderate course of disease and 14% of them had a severe course and were admitted to our intensive care unit. At the time of the study visit, the majority of patients still complained about symptoms: 40% presented with fatigue and weakness, 36% with exertional dyspnea, 21% with vertigo, 17% had an impaired taste or smell. Only 28% were completely asymptomatic (figure 1). From a cardiac perspective, the only abnormal findings noted in echocardiography studies were reduced left ventricular global longitudinal strain. Cardiac MRI revealed pericardial effusion in 19%, however, these were only minimal (≤9mm) and not visible in echocardiography. Furthermore, cardiac MRI showed positive late gadolinium enhancement in 11%. Pulmonary function tests were abnormal in 16%. Pulmonary CT scans showed post infectious residues like bilateral ground glass opacities and fibrosis in 45%. Exercise capacity as measured by the 6-minute walk test with BORG Dyspnea Score and by spiroergometry was reduced in almost 40% of our study participants.

Conclusions
This interim analysis showed that most previously hospitalized patients still suffer from chronic fatigue, exertional dyspnea and impaired cardiopulmonary function after Covid-19 infection. Furthermore, even though cardiac and pulmonary imaging revealed numerous pathologic findings, and exercise capacity was reduced, no correlations could be found with persisting symptoms.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Klink Favoriten and Medical University hospital Vienna