Cintilografia pulmonar de perfusão em pacientes egressos de internação hospitalar por Síndrome Respiratória Aguda Grave decorrente da infecção pelo SARS-CoV-2

Abstract

COVID-19, caused by SARS-CoV-2, is a highly transmissible respiratory disease identified in December 2019 and declared a pandemic in March 2020. Responsible for over 7.1 million deaths worldwide, including 714,000 in Brazil, it has presented systemic complications such as thrombosis. Chronic vascular changes resulting from SARS-CoV-2 infection remain unknown. To assess the presence of perfusion defects identified through pulmonary scintigraphy 180 days post-diagnosis of COVID-19 in patients who were treated in the intensive care unit for severe COVID-19. Additionally, to evaluate the associated symptoms, lung function, and quality of life. This is a multicenter, prospective observational study carried out in public hospitals in Belo Horizonte, Minas Gerais, which included 383 patients hospitalized for severe COVID-19 between November 2020 and December 2021, followed up for 180+30 days after diagnosis. Clinical and laboratory variables were collected on admission and perfusion scintigraphy, chest computed tomography and functional assessment after 6 months. The data was stored on the RedCap platform and analyzed using SPSS 28.0 software, using t-tests, MannWhitney, and Pearson's chi-square tests. Means and standard deviations, medians, and IQ intervals were described using univariate and multivariate logistic regression analysis. The study was approved by the Ethics Committees of the institutions involved (CAAE 30753020.1.1001.5149). Ninety-seven patients were evaluated (55% male; mean age 58±11.5 years). Pulmonary scintigraphy indicated defects suggestive of pulmonary thrombosis in 15 patients (15.5%). Of these, 12 (80%) exhibited significant radiological changes. Ventilatory disorders were identified in 35 (36.1%) of participants via spirometry, while gas exchange disorders were present in 11(11.4%). Prophylactic anticoagulation was found to be a protective factor with an effect of 93% (95% CI, 0.01 to 0.75; p = 0.023). No significant correlations were found between initial symptoms, radiological findings, mechanical ventilation approaches, or treatment protocols and follow-up scintigraphy results. The occurrence of perfusion defects on lung scintigraphy six months after severe COVID-19 is relatively frequent, but their clinical impact is uncertain, since they have not been associated with symptoms. The protective effect of prophylactic anticoagulation found in this series needs to be verified in studies involving a larger number of participants and with specific designs for this purpose