Long-Term Cardiopulmonary Function After COVID-19-Associated Acute Respiratory Distress Syndrome: A Multicenter Case-Control Study

Abstract

Objectives: This study aimed to evaluate long-term pulmonary function, cardiopulmonary exercise capacity, chest CT findings, and health-related quality of life (HRQoL) in survivors of COVID-19 complicated by acute respiratory distress syndrome (ARDS).

Design, setting, and patients: This is a multicentric case-control study conducted from February 2023 to December of 2023. Pulmonary function tests, cardiopulmonary exercise testing (CPET), chest CT, and HRQoL (using EuroQol 5D three-level [EQ-5D-3L]) were performed at least 12 months after hospital discharge among cases (COVID-19 complicated by ARDS) and at the time of inclusion among controls (family members/friends matched for sex and age).

Interventions: None.

Measurements and main results: A total of 114 COVID-19 ARDS survivors and 115 controls were included. The mean age was 54 years and 52.4% of the participants were men. Time from hospital discharge to evaluation was 22 months (20.99-41.41 mo) among cases. Persistent symptoms, including memory loss (48.2%), fatigue (42.1%), and anxiety (31.6%), were reported by 73.6% of the COVID-19 ARDS survivors. Cases had significantly reduced pulmonary function, with lower diffusing capacity for carbon monoxide (DLCO) of 6.85 mmol/min/Kpa (5.44-8.37 mmol/min/Kpa) vs. 7.36 mmol/min/Kpa (6.43-8.96 mmol/min/Kpa; p = 0.012) and % of predicted DLCO of 81.0% (70.2-90.4%) vs. 89.3% (78.9-99.9%; p < 0.001), compared with controls, as well as a higher frequency of moderate to severe DLCO impairment (10.5% vs. 0.8%; p = 0.002). In CPET, cases demonstrated lower peak oxygen consumption (21.9 mL/kg/min [18.2-29 mL/kg/min] vs. 25.8 mL/kg/min [21.6-31.9 mL/kg/min]; p < 0.001). Chest CT revealed a greater prevalence of ground-glass opacities in cases (53.5% vs. 16.5%; p < 0.001) and emphysema (6.1% vs. 0%; p = 0.043). HRQoL, using EQ-5D-3L utility scores, were significantly lower in cases, with worse mobility (p < 0.001), self-care (p < 0.001), and anxiety/depression (p = 0.04) dimension scores compared with controls.

Conclusions: COVID-19 ARDS survivors exhibit significant long-term impairments in pulmonary function, exercise capacity, and quality of life and abnormal chest CT findings compared with family controls with same sex and age.

Keywords: COVID-19; exercise test; pulmonary function test; respiratory distress syndrome; severe acute respiratory syndrome coronavirus 2.