ABSTRACT
Long COVID-19 is defined as persistency of symptoms, such as exertional dyspnea, twelve weeks after recovery from SARS-CoV-2 infection;its pathophysiology still needs to be fully understood. We investigated exercise tolerance and ventilatory efficiency using cardiopulmonary exercise testing (CPET) in patients with long COVID-19. Methods. One hundred patients admitted to our hospital from March to August 2020 for a moderate to critical COVID-19 were enrolled in our long COVID-19 program. Medical history, physical examination and chest HRCT were obtained at hospitalization (T0), at 3 (T3) and 15 months (T15). All HRCTs were revised using a semiquantitative CT severity score (Pan, F. et al. Radiology 2020;295(3):715-721). Pulmonary function tests (PFTs) were obtained at T and T . CPET was performed at T15 in twenty patients (10 male/10 female;mean age 62 years) with residual respiratory symptoms (e.g., exertional dyspnea) and/or an impairment in PFTs, DLCO and/or KCO . Results. At CPET, peak oxygen uptake (VO2 -peak) and ventilatory efficiency (VE /VCO2 slope) were 95.9+/-18.4 SD %pred and 31.4+/-3.9 SD, respectively. Of notice, significant correlations between VE/V'CO2 slope and CT score (T0 ) (r=0.403;p=0.039), CT score (T3) (r=0.453;p=0.022) and DLCO (T3 ) (r=-0.465;p=0.019) were observed. Conclusions. At fifteen-months from COVID-19 pneumonia, a significant number of subjects (20%) still complains of exertional dyspnea. At CPET this may be explained by reduced ventilatory efficiency (i.e., increase in VE/VCO2), possibly related to the degree of lung parenchymal involvement in the COVID-19 acute phase, likely reflecting a damage in the interstitial/pulmonary capillary structure.
ABSTRACT
Post COVID-19 Interstitial Lung Disease (PC-ILD) is characterized by fibrotic-like signs at HRCT and PFTs abnormalities after SARS-CoV-2 infection. It is still not clear how frequent these tests should be performed to rule out long-term consequences of COVID-19 pneumonia. The aims of our study are to evaluate the incidence and risk factors of PC-ILD and possibly to propose a long-term follow-up program. One-hundred patients, hospitalized in our ward for moderate to critical COVID-19, underwent two follow-up visits at 3 and 15 months in which PFTs and HRCT were performed. At the fifteen-month follow-up, 8 patients (~8%) showed residual radiological and functional signs consistent with PCILD. All but one of these patients had already demonstrated PFTs and HRCT alterations at first follow-up visit, the last one patient showed worsening of lung function during follow up: these findings highlight the negative predictive value of PFTs, at three months follow-up, for the development of PC-ILD. Ageing, severity of COVID-19 and degree of pulmonary involvement during acute infection proved to be significant risk factors for developing PC-ILD. PC-ILD is likely to occur in less than 10% of our patients affected by moderate to critical COVID-19. Our study highlights the importance of PFTs in the long-term follow-up of these patients, but further studies are needed to confirm our hypothesis that HRCT should be performed only in patients with PFTs abnormalities.
ABSTRACT
COVID-19 patients suffering sudden worsening of clinical conditions have an atypical peripheral pulmonary arterial obstruction at computed tomography pulmonary angiogram (CTPA), poorly associated to deep venous thrombosis (DVT), suspicious for thrombotic in situ nature rather than embolic.