Long-term Evolution of Pulmonary Involvement of Novel SARS-COV-2 Infection (COVID-19): Follow the Covid Study

Coronaviruses are a family of viruses with marked tropism for the respiratory system, being
able to cause heterogeneous pathological states in humans ranging from the common cold to
more serious diseases such as Respiratory Syndrome severe acute respiratory syndrome (SARS).
In December 2019 in Wuhan in China, the first case of human infection by a new coronavirus
was identified, currently called SARS-COV-2 (Severe Acute Respiratory Syndrome - Coronavirus
- 2), characterized by high contagiousness and the possibility of causing a severe acute
respiratory distress syndrome from which its acronym derives and which caused the state of a
global pandemic in a few months. The disease caused by the SARS-COV-2 virus is called COVID
19.

The most frequent clinical manifestation of COVID-19 is pneumonia, which in about 20% of
cases results in acute respiratory failure requiring oxygen therapy or ventilatory support.
sometimes resulting in a picture similar to that caused by acute respiratory distress
syndrome (ARDS), found in 60-70% of patients admitted to intensive care. The pathogenesis of
classical ARDS involves three phases of the disease: an exudative, a proliferative and a
fibrotic phase, which occurs when the removal of alveolar collagen fails and leads to
progressive pulmonary fibrosis. It is not known whether the long-term evolution of the COVID
19 disease could result in the establishment of a fibrotic phase similar to that predicted by
the pathogenesis of classical ARDS, which would lead to a chronic ventilatory deficit similar
to that of pulmonary interstitial diseases, with serious impact on quality of life and
mortality.

However, it is not well-known whether SARS-COV-2 pneumonia causes restitutio ad integrum or
whether it can induce persistent parenchymal alterations and lung function abnormalities.

Very few studies have so far addressed the problem of clinical and functional recovery in
these patients, most of them just before or after discharge and none specifically focused on
patients admitted for ARF. Indeed most of these investigations were limited to a specific
field such as symptoms, pulmonary function and radiological changes.There are no guidelines
for the follow-up of COVID-19 patients, despite the British Thoracic Society (BTS) has
published a guidance for scheduling post-hospitalization assessments.

Aim of this study, spontaneous,observational, both prospectic and retrospective, is to
describe the long term (6 to 12 months) evolution of lung involvement in patients discharged
after an episode of ARF due to COVID-19, identifying possible factor associated to lasting
clinical, functional or radiological abnormalities.

Investigators will collect clinical, functional and radiological parameters during:

- the hospital stay due to COVID-19 (H);

- the 1-month after hospital discharge followup visit (V1);

- the 3-months after hospital discharge followup visit (V2);

- the 6-to-12-months after hospital discharge followup visit, performed for study subjects
that at V2 show clinical and/or functional and/or radiological abnormalities due to
sequelae of COVID-19 (V3).

For data analysis, all variables will be analyzed using descriptive method. Continuous
variables will be presented as means, standard deviation, median and respective minimum and
maximum values; the discrete or nominal variables will be expressed as frequencies and
relative percentages. Subgroup analysis will be performed using X- 2 test or Fischer test
when appropriate; parametric variables not normally distributed will be analyzed by
Kruskal-wallis non-parametric test. Association between two or more parameters will be
calculate with Spearman Correlation. p <0.05 values will be considered statistically
significant.

This study was approved by the Local Ethic Committee.