Dorelli G; Braggio M; Gabbiani D; Busti F; Caminati M; Senna G; Girelli D; Laveneziana P; Ferrari M; Sartori G;
Dalle Carbonare L; Crisafulli E;

Diagnostics (Basel, Switzerland) [Diagnostics (Basel)] 2021 Mar 12; Vol. 11 (3). Date of Electronic Publication: 2021 Mar 12.

The cardiopulmonary exercise test (CPET) provides an objective assessment of ventilatory limitation, related to the exercise minute ventilation (V _E ) coupled to carbon dioxide output (V _CO2 ) (V _E /V _CO2 ); high values of V _E /V _CO2 slope define an exercise ventilatory inefficiency (EV in ). In subjects recovered from hospitalised COVID-19, we explored the methodology of CPET in order to evaluate the presence of cardiopulmonary alterations. Our prospective study (RESPICOVID) has been proposed to evaluate pulmonary damage’s clinical impact in post-COVID subjects. In a subgroup of subjects (RESPICOVID2) without baseline confounders, we performed the CPET. According to the V _E /V _{CO2 slope} , subjects were divided into having EV in and exercise ventilatory efficiency (EV ef ). Data concerning general variables, hospitalisation, lung function, and gas-analysis were also collected. The RESPICOVID2 enrolled 28 subjects, of whom 8 (29%) had EV in . As compared to subjects with EV ef , subjects with EV in showed a reduction in heart rate (HR) recovery. V _E /V _{CO2 slope} was inversely correlated with HR recovery; this correlation was confirmed in a subgroup of older, non-smoking male subjects, regardless of the presence of arterial hypertension. More than one-fourth of subjects recovered from hospitalised COVID-19 have EV in . The relationship between EV in and HR recovery may represent a novel hallmark of post-COVID cardiopulmonary alterations.