Differencies between former smokers and non-smokers during post-Covid period

Previous studies comparing treatment outcomes and the recovery of smokers after COVID 19 infection have yielded contradictory results. The aim of this retrospective study was to compare recovery and the rate of posthospital complications of former long-term smokers (FS) with non-smoking (NS) controls observed in PostCovid out-clinic hospital. We compared 88 FS and 96 NS, who had suffered from moderate to severe Covid-19 pneumonia, and were observed during 1-year follow-up period. The inclusion criteria were positive PCR test for SARS-CoV-2 infection and hospitalization due to acute respiratory failure. We compared lung function tests, blood gas analyses, onset of new symptoms and incidence of thrombotic incidents. Mean age of participants was 64.8+/-11.4 years for NS and 63.8+/-8.8 years for FS. At the beginning of follow-up FS group had significantly lower pulmonary function tests vs NS, including FEV1 (89.9% vs 94.6%, p<0.01);FVC (87.5% vs 94.3%, p< 0.01);DLco (62.3% vs 72.7%, p< 0.01), with a tendency for slower recovery during subsequent examinations. There was no significant difference between two groups regarding blood gas levels, number of reported symptoms and incidence of pulmonary embolism (7 vs 7). According to the results we can conclude that former smokers initially had worse lung function scores and prolonged recovery course. However, there was no significant difference in the number of symptoms and the frequency of thrombotic complications.

Venous and arterial thromboses in hospitalized patients with acute COVID-19 at University Hospital Dubrava

Since COVID-19 pandemic has started, there have been reports that SARS-CoV-2 infection induces pro-thrombotic state. Even though the disease presents foremost with respiratory symptoms, high frequencies of both venous and arterial thromboses have been observed while suggesting different molecular mechanisms. University Hospital Dubrava has been Croatia capital's COVID-19 centre for almost a year and a half treating almost 10.000 patients until today. We retrospectively analysed venous and arterial thrombotic events among 4014 patients hospitalized due to COVID-19. Venous thromboembolic events (VTE) occurred in 5.3% and arterial thrombotic events (ATE) in 5.8% of patients. Majority of ATE occurred prior or on the day of admission while VTE were mainly detected during hospitalization (screening). Majority of both occurred prior to intensive care unit (ICU) admission, but both were associated with higher need for ICU care and prolonged immobilization. In multivariate logistic regression analysis independent factors associated with VTE were metastatic malignancy, known thrombophilia, higher D-dimers, longer duration of disease on admission, bilateral pneumonia, longer duration of hospitalization and immobilization for at least one day. On the other hand, factors that showed to be associated with ATE were less severe COVID-19, higher Charlson comorbidity index, history of arterial diseases, aspirin use, lower C reactive protein, better functional status on admission and immobilization for at least one day. In conclusion, venous and arterial thromboses differ in all above mentioned factors thus leaving room for appropriate prevention, intervention and treatment.

Histopathologic changes in lung tissue after Covid-19 pneumonia

Current knowledge of histopathological changes in Covid-19 pneumonia is mainly based on autopsy findings. There are few data on dynamics of lung lesions in vivo after acute phase of disease. The aim of this study was to determine histopathologic changes during the long/post-Covid stage in patients who had suffered from moderate to severe Covid-19 pneumonia. Bronchoscopy with transbronchial lung biopsy was performed in patients with HRCT lesions involving >40% of lung parenchyma, at least 4 weeks after discharge. Additional criteria were restrictive pattern in lung function tests and signed informed consent. Histopathologic analyses were performed using H&E, MSB, MOVAT, TTF1, CD34 and CD68 staining. Research was approved by the Hospital Ethical Committee. Among 26 patients that met inclusion criteria, adequate biopsy samples were obtained from 24. The mean time from the onset of disease to biopsy was 13 weeks. We found 4 histopathologic patterns: diffuse alveolar damage-DAD with vascular abnormalities, nonspecific interstitial inflammation, organizing pneumonia and interstitial fibrosis in 11, 9, 2 and 2 patients, respectively. Vascular abnormalities included capillary thrombi, dilated venules and dissection of small pulmonary arteries. Given the duration of disease, DAD and vascular abnormalities were detected up to the 12 week from the onset of symptoms. All patients biopsied after 12th weeks had some degree of tissue inflammation without vascular changes. Our findings show rather slow recovery of lung tissue after Covid-19 pneumonia. Long lasting DAD with vascular abnormalities may explain prolonged dyspnea and exercise intolerance and should be taken into consideration when planning further rehabilitation.