TRAJECTORY OF RECOVERY IN PULMONARY FUNCTION TESTS FOR PATIENTS WITH RESPIRATORY POSTACUTE SEQUELAE OF COVID-19 INFECTION

ABSTRACT

SESSION TITLE Long COVID It Can Take Your Breath Away SESSION TYPE Original Investigations PRESENTED ON 10/16/2022 1030 am - 1130 am PURPOSE: Post-acute sequelae of COVID-19 (PASC) infection is an area of active research, and much remains unknown about the trajectory of respiratory system recovery. While chronic dyspnea is a commonly reported PASC symptom, it is unclear how objective lung function metrics change over time. In this study, we sought to in lung function in PASC by comparing serial pulmonary function tests (PFTs) after COVID-19 infection. METHODS: Patients with prior COVID-19 infection and at least two PFTs after acute infection were identified retrospectively from our COVID-19 recovery clinic at a tertiary care center in Chicago, Illinois. PFT data and other clinical information were ed from the electronic medical record. Using a matched paired t-test, the differences between forced expiratory volume at one second (FEV1), forced vital capacity (FVC), total lung capacity (TLC), and diffusion capacity of carbon monoxide (DLCO) were compared over time. RESULTS: There were 32 patients who underwent pulmonary function testing twice after COVID-19 illness from 2020-2022, with a mean age of 56 years. The majority of the cohort were female (59%) and white (56%). 16 patients (50%) had required hospitalization for their acute COVID-19 illness, and 7 (22%) had required ICU level of care. The mean time from illness onset to first PFT was 207 days, and the mean time between the first and second PFT was 204 days. There was a statistically significant increase in FVC (2.2%, p=0.01), TLC (2.2%, p=0.01), and DLCO (2.43 mL/min/mmHg), but not in FEV1. Rate of change was calculated for each patient by dividing the difference for each parameter by the time (in years) between PFTs. TLC improved most rapidly (median 10.9% per year, IQR 0-24), followed by DLCO (median 6.6% per year, IQR -1 – 19.4). FEV1 increased by 3.9% per year (IQR -12.5 – 22), and FVC increased by 5.1% per year (IQR -4.5 – 22.7). Rate of change was calculated for each patient by dividing the difference for each parameter by the time (in years) between PFTs. TLC improved most rapidly (median 10.9% per year, IQR 0-24), followed by DLCO (median 6.6% per year, IQR -1 – 19.4). FEV1 increased by 3.9% per year (IQR -12.5 – 22), and FVC increased by 5.1% per year (IQR -4.5 – 22.7). CONCLUSIONS: There was an improvement in lung function metrics in our PASC cohort. This data describes the rate of improvement for each parameter, which may be helpful in prognostication and counselling patients about expected recovery times. CLINICAL IMPLICATIONS A large number of patients with PASC experience chronic dyspnea and have persistent radiographic changes and/or abnormal pulmonary function testing. Our data suggests that for patients with abnormal PFTs, there is gradual improvement over time. With the burden of COVID-19 illness worldwide, it is crucial that we can accurately risk stratify those at high risk for persistent symptoms as well as understand the trajectory of recovery. DISCLOSURES no disclosure submitted for Joseph Bailey;No relevant relationships by Amy Ludwig No relevant relationships by Marc Sala