Symptom Persistence Despite Improvement in Cardiopulmonary Health - Insights from longitudinal CMR, CPET and lung function testing post-COVID-19

Background: The longitudinal trajectories of cardiopulmonary abnormalities and symptoms following infection with coronavirus disease (COVID-19) are unclear. We sought to describe their natural history in previously hospitalised patients, compare this with controls, and assess the relationship between symptoms and cardiopulmonary impairment at 6 months post-COVID-19. Methods: Fifty-eight patients and thirty matched controls (single visit), recruited between 14th March -25th May 2020, underwent symptom-questionnaires, cardiac and lung magnetic resonance imaging (CMR), cardiopulmonary exercise test (CPET), and spirometry at 3 months following COVID-19. Of them, forty-six patients returned for follow-up assessments at 6 months. Findings: At 2-3 months, 83% of patients had at least one cardiopulmonary symptom versus 33% of controls. Patients and controls had comparable biventricular volumes and function. Native cardiac T1 (marker of fibroinflammation) and late gadolinium enhancement (LGE, marker of focal fibrosis) were increased in patients at 2-3 months. Sixty percent of patients had lung parenchymal abnormalities on CMR and 55% had reduced peak oxygen consumption (pV?O2) on CPET. By 6 months, 52% of patients remained symptomatic. On CMR, indexed right ventricular (RV) end-diastolic volume (-4.3 mls/m(2), P=0.005) decreased and RV ejection fraction (+3.2%, P=0.0003) increased. Native T1 and LGE improved and was comparable to controls. Lung parenchymal abnormalities and peak (V)over dotO(2), although better, were abnormal in patients versus controls. 31% had reduced p(V)over dotO(2) secondary to symptomatic limitation and muscular impairment. Cardiopulmonary symptoms in patients did not associate with CMR, lung function, or CPET measures. Interpretation: In patients, cardiopulmonary abnormalities improve over time, though some measures remain abnormal relative to controls. Persistent symptoms at 6 months post-COVID-19 did not associate with objective measures of cardiopulmonary health. (C) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Automated summary

The study found that cardiopulmonary abnormalities in patients infected with COVID-19 improve over time, but some measures remain abnormal compared to controls. Persistent symptoms at 6 months post-COVID-19 were not significantly associated with objective cardiopulmonary health measures, indicating a complex relationship between symptoms and physiological abnormalities.