A recent prospective cohort study posted to the Research Square* preprint server and under consideration at Scientific Reports assessed the cardiopulmonary effects in patients six months after coronavirus disease 2019 (COVID-19) infection.
Ever since the COVID-19 pandemic began, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected more than 420 million people and killed over 5.9 million of them. Despite the high recovery rate observed for COVID-19, various studies suggest the persistence of physical, mental, and cognitive disturbances for several months after recovering from the illness.
Symptoms of this post-COVID-19 syndrome include depression, fatigue, anxiety, self-care issues, and pain, among others. Nonetheless, there is a growing consensus to engage these patients with multidisciplinary psychological and physical approaches to precisely evaluate the symptoms with standardized questionnaires and functional assessments like cardiopulmonary examinations.
According to one study, COVID-19 patients who required intensive care unit (ICU) admission during their acute infection phase complained of lingering symptoms even after four months of recovery. Follow-up examinations of these ICU-admitted patients revealed that the left ventricular ejection fraction (LVEF) was <50% in about 10% of them. Additionally, global longitudinal strain (GLS) analysis could prove vital in assessing the LV functions in patients with post-COVID-19 syndrome. Some researchers argue that GLS analysis might be more informative on LV dysfunction than LVEF.
In the present study, researchers determined the psychological and physical symptoms of COVID-19 survivors. Around 60 COVID-19 patients were included in the study who were hospitalized due to severe dyspnea, elevated respiratory rate, signs of acute organ dysfunction, or the need for oxygen therapy in patients without any history of respiratory failure. Patients were advised follow-up appointments at the pulmonary department after discharge.
Patients were subject to a standard clinical interview conducted by trained physicians and nurses. They were asked about daily life activities, mental and physical exhaustion, and any changes that altered their urge to pursue everyday life. Further, the researchers performed complete pulmonary function tests (PFTs), electrocardiography, and transthoracic electrocardiography (TTE).
LVEF was quantified in four- and two-chamber views using Simpson's Biplane method. Next, a myocardium deformation analysis was carried out to assess the peak GLS of the myocardium. GLS was evaluated in four-, two-, and apical three-chamber views by speckle-tracking echocardiography.
Patients completed patient health questionnaire 9 (PHQ-9) of depression, generalized anxiety disorder 7 (GAD-7), St. George’s respiratory questionnaire (SGRQ), and Euro Quality of life - five Dimensions - five Levels (EQ-5D-5L) questionnaire. Lastly, whole-body plethysmography and blood gas analyses (BGA) were performed; all patients took a 6-minute walk test (6MWT) with no supplemental oxygen.
All patients were aged around 61 ± two years, with a majority (67%) being males. Follow-up examination six months post-discharge noted fatigue as the most common (28 %) symptom in patients. Fatigue was described as the inability or difficulty to start any activity, demotivating them from engaging in basic and routine work. Fatigue patients were more likely to complain of poor quality of life (QoL) than others. Moreover, patients experiencing fatigue had poorer scores of depression and anxiety than those without fatigue.
Plethysmography and BGA identified no significant impairments other than fatigue. Echocardiography revealed that the mean LVEF values were normal for all patients. The authors observed impaired GLS upon performing LV myocardial deformation analysis, but the differences were insignificant between patients with fatigue and those without. Additional comparison between ICU-admitted patients and those treated on general wards showed no differences in LVEF or GLS.
The current study observed fatigue as the most common symptom six months post-COVID-19. In addition to experiencing fatigue, these patients had challenges maintaining routine daily-life activities. They showed higher levels of depression and anxiety, probably due to the elevated burden of symptoms and limited or no mobility.
GLS analysis identified subtle myocardial dysfunction, although insignificant, between patients with and without fatigue. Nevertheless, all patients had mild to moderate anxiety and depression regardless of fatigue. Although subtle myocardial dysfunction is common after COVID-19 infection, it could not explain the prevalence of fatigue observed in this study.
Notably, the study could not implement radiological examinations, providing information on interstitial changes in the lungs and pulmonary fibrosis. Moreover, it remains unclear whether COVID-19-associated fatigue after six months of recovery is due to chronic respiratory muscle dysfunction, paving the way for more research in that direction.
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