Standardized Clinical, Functional, and Radiological Pulmonary Follow-Up in Patients Discharged with Diagnosis of COVID-19 from an Italian Hospital -Preliminary Data

Aim: To describe the standardized methodology of the clinical-functional-radiological pulmonary follow-up (F-up) planned for COVID-19 patients discharged from the Pisa University Hospital, Italy. Methods: COVID-19 patients are identified by Hospital Discharge Form code. One month after discharge (T1), symptoms are assessed through a telephone questionnaire. Three months after discharge (T3), patients are proposed to undergo: pulmonary visit, spirometry, plethysmography, DLCO, ABG analysis (if SpO2<95%), chest CT, chest ultrasound, blood test, salivary test. Subsequent F-up for individual patients is based on the combination of standardized comparisons of chest CT (T3 vs. baseline), lung function (presence/absence of spirometric and/or DLCO abnormalities at T3) and respiratory symptoms (T3 vs. T1), as follows: (A) worsening/occurrence of COVID-19 pneumonia chest CT signs, regardless of functional abnormalities and/or respiratory symptoms;F-up is planned at 6 months (T6), with chest CT and clinical-functional evaluation. (B) stability/improvement of COVID-19 pneumonia, with (B1) or without (B2) functional abnormalities and/or respiratory symptoms;F-up is planned at 12 months (T12) with chest CT for both (B1) and (B2), and at T6 with clinical-functional evaluation for (B1). (C) complete resolution of COVID-19 pneumonia, regardless of functional abnormalities and/or respiratory symptoms;F-up is planned at T12, with clinical-functional evaluation. Results: Up to 08/10/2020, n=316 patients were discharged (17% hospitalized ≥3 days in ICU). Up to 01/12/2020, n=162/316 (51,3%) underwent T3-F-up;n=60/316 patients (18.9%) waiting for T3-F-up;n=38/316 (18%) lost to F-up;n=31/316 (9.8%) refusing F-up;n=20/316 (6.3%) died after discharge. Among patients who completed T3-F-up, n=12/162 (7,4%), n=33/162 (20,4%), n=32/162 (19,7%), and n=85/162 (52,5%) were assigned to F-up (A), (B1), (B2), and (C), respectively. The worse the radiological imaging, the higher the median age of the patients (74-, 67-, 68-, and 56-years median age, respectively). In n=65/162 (40,1%) patients, chest CT detected collateral findings (e.g., pulmonary nodules). 57,4% of patients showed normal lung function tests, while 24.5% showed a reduction of DLCO. 64,1% of patients were asymptomatic, 32.7% showed improved/stable, and 3% showed worsening respiratory symptoms. Conclusions: More than half hospitalized COVID-19 patients shows complete resolution of pneumonia chest CT signs and normal lung function at T3-F-up. For a disease whose natural history is yet unknown, a standardized clinical-functional-radiological pulmonary evaluation may serve as tentative guideline for planning F-up. To date such an approach is ongoing and under evaluation.