Study on the utility and efficacy of clinical and instrumental tests in the follow-up of COVID-19 patients

Introduction: The disease caused by the SARS-CoV-2 virus (COVID-19) frequently leads to serious complications and prolonged hospitalizations requiring effective care after discharge. Aim of the study: Aim of this study was to identify feasible and cost-effective predictors of outcome among clinical characteristics, functional status, laboratory, echocardiographic and lung ultrasound data of COVID-19 patients. Material and methods: Patients affected by COVID-19 who experienced a prolonged hospitalization due to a severe form of the disease and that have been discharged from the COVID-19 rehabilitation unit (RU) were prospectively enrolled between April 6th and May 22nd, 2020. All the patients underwent a 6-minute walk test (6MWT) at the 30-day follow-up. Baseline characteristics, laboratory, functional exercise tests, echocardiographic and lung ultrasound (LUS) data collected between hospitalization, admission to RU, discharge from RU and follow-up were compared. Correlations with the predicted distance covered at the 6MWT (6MWD) were made. Results: 40 patients met inclusion criteria and presented to follow-up (13 women [32.5%] and 27 men [67.5%]; mean age 66 ± 10 years). Among all variables analysed, only functional tests at discharge showed a remarkable correlation with the 6MWD. Significant improvement in lung ultrasound score (LUSS) was also observed however without correlation with 6MWD. Conclusions: functional tests at discharge from RU identified patients with different 30-day outcomes that could deserve a stricter long-term follow-up. This may help in planning a personalized follow-up. The costs and effort were minimal. The severity of the acute phase did not significantly influence functional recovery. LUS was useful to identify subclinical lung damage and its evolution over time, however without clear functional correlation.