Changes in cardiopulmonary exercise capacity and limitations 3–12 months after COVID-19

RationaleTo describe cardiopulmonary function during exercise 12 months after hospital discharge for coronavirus disease 2019 (COVID-19), assess the change from 3 to 12 months, and compare the results with matched controls without COVID-19.MethodsIn this prospective, longitudinal, multicentre cohort study, hospitalised COVID-19 patients were examined using a cardiopulmonary exercise test (CPET) 3 and 12 months after discharge. At 3 months, 180 performed a successful CPET, and 177 did so at 12 months (mean age 59.3 years, 85 females). The COVID-19 patients were compared with controls without COVID-19 matched for age, sex, body mass index and comorbidity. Main outcome was peak oxygen uptake (V′O2 peak).ResultsExercise intolerance (V′O2 peak<80% predicted) was observed in 23% of patients at 12 months, related to circulatory (28%), ventilatory (17%) and other limitations including deconditioning and dysfunctional breathing (55%). Estimated mean difference between 3 and 12 months showed significant increases inV′O2 peak% pred (5.0 percentage points (pp), 95% CI 3.1–6.9 pp; p<0.001),V′O2 peak·kg−1% pred (3.4 pp, 95% CI 1.6–5.1 pp; p<0.001) and oxygen pulse % pred (4.6 pp, 95% CI 2.5–6.8 pp; p<0.001).V′O2 peakwas 2440 mL·min−1in COVID-19 patients compared to 2972 mL·min−1in matched controls.Conclusions1 year after hospital discharge for COVID-19, the majority (77%), had normal exercise capacity. Only every fourth had exercise intolerance and in these circulatory limiting factors were more common than ventilator factors. Deconditioning was common.V′O2 peakand oxygen pulse improved significantly from 3 months.