ABSTRACT
Background: Patients suffering from Post-Acute Sequelae of SARS CoV-2 (PASC) infection may benefit from a pulmonary rehabilitation program (PRP). However, patients respond differently to the protocols. Treatment selection based on sensitive endpoints remains arbitrary. Can quantitative CT play a role in providing a safe, effective PRP? Methods: Two patients admitted for PRP were tested. A low dose quantitative CT scan was taken. Functional respiratory imaging (FRI) was performed on the scans. FRI, Lung function and blood vessel analysis were used for clinical decision making in treatment protocol. Result(s): At visit 1, patient 1 showed a significant decrease in small blood vessel volume and increased volume for the larger vessels (fig 1). This vascular redistribution resulted in cardiac disturbances. Therefore, patient 1 was treated with corticosteroids. Patient 2 showed no deviations on the proportion of blood volume in vessels with a cross-sectional area between 1.25 and 5mm2 (BV5%) and enrolled in the PRP. Patients were re-evaluated after 3 months. Patient 1 improved significantly, recovered, and showed normalized results in BV5%. In Patient 2 V02max changed from 1728 to 2738 ml/min from 52% to 84% predicted. Conclusion(s): Vascular density endpoints as BV5% can be considered as identifier for selection of patient for a PRP in long-COVID, and potentially other pathologies. Once normalized, patients can safely enroll in a PRP.
ABSTRACT
TOPIC: Chest Infections TYPE: Original Investigations PURPOSE: SARS-CoV-2 is a highly contagious respiratory virus associated with significant morbidity and mortality in the acute phase. It is also associated with long-term morbidity in a subset of patients. It is not clear which patients will have persistent symptoms. SARS-CoV-2 affects the pulmonary vasculature. We hypothesize that differences in blood volume measurements on CT of the chest during the acute phase are associated with significant dyspnea after the acute phase. METHODS: We retrospectively studied subjects hospitalized for COVID-19 pneumonia who had an initial and follow-up CT chest, pulmonary function tests (PFTs), 6-minute walk test (6MWT), and a clinical assessment in our post-COVID-19 clinic. We excluded subjects with pre-existing lung disease based on prior PFTs. Serum inflammatory biomarkers, CT scan, and clinical characteristics were assessed during the hospitalization. CT images were evaluated by Functional Respiratory Imaging (deep learning trained) with automated tissue segmentation algorithms of the lungs and pulmonary vasculature. Volumes of the pulmonary vessels that were ≤5mm2 (BV5), 5-10mm2 (BV5_10), and ≥10mm2 (BV10) in cross-sectional area were analyzed. Additionally, the amount of opacification on CT (i.e., ground-glass opacities, crazy paving, reticular disease and edema) was quantified in each patient. PFTs were performed <3 months after discharge. We defined a modified Medical Research Council (mMRC) score≥2 as having significant dyspnea. We compared subjects with an mMRC score≥2 to those with an mMRC score<2. BV measures were also compared to a historical cohort of healthy controls. RESULTS: 50 subjects were included. 22 had mMRC score≥2. The groups had similar baseline characteristics. Admission hemoglobin, peak inflammatory biomarkers, and follow-up PFTs were similar between groups. On 6MWT, there were no differences between groups in resting SpO2, lowest SpO2, or walk distance. On admission CT, percent BV5 was lower, and percents BV5_10 and BV10 were higher in the mMRC≥2 group compared to the mMRC<2 group. All BV measures in both groups were different compared to healthy controls. At follow-up, BV5 measures in the mMRC≥2 group improved but remained abnormal compared to healthy controls, without a statistical difference compared to the mMRC<2 group. Opacification was similar between groups on admission and follow-up CTs. CONCLUSIONS: Despite similar baseline characteristics, lung function, degree of opacification and oxygenation, persistent dyspnea after COVID-19 pneumonia is related to pruning of the small pulmonary vessels (BV5) during the acute phase and not to differences in vascular abnormalities seen in short term follow-up. CLINICAL IMPLICATIONS: Identification of markers of persistent dyspnea in post-acute COVID-19 contributes to a better understanding of the natural course and prognosis of the disease. This will impact research and patient care in the near future. DISCLOSURES: No relevant relationships by Melinda Darnell, source=Web Response Owner/Founder relationship with Fluidda Please note: $20001 - $100000 by Jan De Backer, source=Web Response, value=Ownership interest No relevant relationships by Derlis Fleitas Sosa, source=Web Response No relevant relationships by Victor Kim, source=Web Response Employee relationship with FLUIDDA Please note: 02/01/2017 - Present Added 04/26/2021 by Maarten Lanclus, source=Web Response, value=Salary No relevant relationships by Ifeoma Oriaku, source=Web Response No relevant relationships by Daniel Salerno, source=Web Response
ABSTRACT
Rationale: Coronavirus Disease 2019 (COVID-19) is a highly contagious respiratory viral illness causing pneumonia and systemic disease. Abnormalities in pulmonary function after COVID-19 infection have been described. The determinants of these abnormalities are unclear. We hypothesized that inflammatory biomarkers and computed tomography (CT) scan parameters at the time of infection would be associated with abnormal gas exchange at short term follow-up.Methods: We studied subjects who were hospitalized for COVID-19 pneumonia and then discharged. Those with pre-existing lung disease (except asthma) or reduced diffusing capacity for carbon monoxide (DLCO) prior to COVID-19 infection were excluded. Information on serum inflammatory biomarkers, CT scan, and clinical characteristics were collected in the index hospitalization. Pulmonary function tests and 6-minute walk tests were assessed at 2-3 months after discharge. CT images at the time of hospitalization were evaluated by Functional Respiratory Imaging (FRI;FLUIDDA, Inc., Antwerp, Belgium) with 3D reconstruction of the lungs and pulmonary vasculature to analyze pulmonary blood volume. Blood volumes of the pulmonary vessels that were ≤5mm (BV5), 5-10mm (BV5-10), and ≥10mm (BV10) in cross-sectional area were analyzed. Additionally, the amount of inflammation on CT (ground-glass opacities) was quantified. We divided subjects into those with a DLCO <80% predicted and those with a DLCO ≥80% predicted based on follow-up pulmonary function tests. Results: 38 subjects were included in our cohort. Pulmonary function tests were performed 76.5±35.1 days after the first day of hospitalization. The results are summarized in the Table. 31 out of 38 (81.5%) subjects had a DLCO<80% predicted. The groups were similar in terms of demographics, body mass index, and smoking status. Peak D-dimer, LDH, and ferritin levels were greater in the DLCO<80% group. Spirometric measures and lung volumes were similar between groups. Inflammation was not different between groups, but BV5-10 and BV10 measures were higher in the DLCO<80% group. BV5-10 was associated with DLCO<80% in multivariable logistic regression with demographics, smoking status, lung volumes, and hemoglobin as covariates (OR 1.29, 95% CI 1.01, 1.64).Conclusions: Higher peak D-dimer levels at the time of hospitalization and abnormalities in pulmonary blood volumes are associated with a reduced DLCO at follow-up. These findings suggest that pulmonary vascular and coagulation abnormalities during hospitalization with COVID-19 might have long-lasting effects on pulmonary function. Further study regarding the influence of pulmonary blood volumes and measures of abnormal coagulation on short term COVID-19 outcomes is warranted.
ABSTRACT
Rationale: Evidence suggests that vascular inflammation and thrombosis may be important drivers of poor clinical outcomes in patients with COVID-19. We hypothesized that a significant decrease in the percentage of blood vessels with a cross-sectional area between 1.25-5 mm2 (BV5%) on chest computed tomography (CT) in COVID-19 patients is predictive of adverse clinical outcomes. Methods: Retrospective study of patients seeking acute medical care within a large integrated healthcare network from 3/1/2020-6/30/2020. Patients presenting to the emergency department, undergoing a chest CT within 24 hours of presentation, and COVID-19 testing were eligible for participation. After identification of the COVID-19-positive cohort, a randomly selected group of COVID-19-negative patients were chosen in order to achieve a target study ratio of 60% COVID-19 positive and 40% COVID-19 negative cases for analysis. Results: Patients with COVID-19 had significantly lower BV5% compared to COVID-19 negative patients (25.3% +/- 7.4 vs 30.1 % +/- 9.6;p<0.01). There was no significant difference in BV5% obtained from contrast enhanced CT versus non-contrast CT (p=0.23). Average processing time for BV5% was 9 minutes and 22 seconds (+/- 6 minutes and 3 seconds), with processing time dependent on scan quality. No CT scans were unable to be analyzed. BV5% was predictive of outcomes in COVID-19 patients in a multivariate model, with a BV5% threshold below 25% associated with an odds ratio (OR) 5.58 for death, OR 3.20 for intubation, and OR 2.54 for the composite of death or intubation. A model using age and BV5% had an area under the receiver operating characteristic curve 0.85 to predict the composite of intubation or death in COVID-19 patients. Conclusion: This data suggests BV5% as a biomarker for predicting adverse outcomes in patients with COVID-19 seeking acute medical care.