Defence Medical Rehabilitation Centre (DMRC) COVID-19 Recovery Service.

Coronavirus disease 2019 (COVID-19) causes significant mortality and morbidity, with an unknown impact in the medium to long term. Evidence from previous coronavirus epidemics indicates that there is likely to be a substantial burden of disease, potentially even in those with a mild acute illness. The clinical and occupational effects of COVID-19 are likely to impact on the operational effectiveness of the Armed Forces. Collaboration between Defence Primary Healthcare, Defence Secondary Healthcare, Defence Rehabilitation and Defence Occupational Medicine resulted in the Defence Medical Rehabilitation Centre COVID-19 Recovery Service (DCRS). This integrated clinical and occupational pathway uses cardiopulmonary assessment as a cornerstone to identify, diagnose and manage post-COVID-19 pathology.

Factors influencing medium- and long-term occupational impact following COVID-19.

BACKGROUND: Significant numbers of individuals struggle to return to work following acute coronavirus disease 2019 (COVID-19). The UK Military developed an integrated medical and occupational pathway (Defence COVID-19 Recovery Service, DCRS) to ensure safe return to work for those with initially severe disease or persistent COVID-19 sequalae. Medical deployment status (MDS) is used to determine ability to perform job role without restriction ('fully deployable', FD) or with limitations ('medically downgraded', MDG). AIMS: To identify which variables differ between those who are FD and MDG 6 months after acute COVID-19. Within the downgraded cohort, a secondary aim is to understand which early factors are associated with persistent downgrading at 12 and 18 months. METHODS: Individuals undergoing DCRS had comprehensive clinical assessment. Following this, their electronic medical records were reviewed and MDS extracted at 6, 12 and 18 months. Fifty-seven predictors taken from DCRS were analysed. Associations were sought between initial and prolonged MDG. RESULTS: Three hundred and twenty-five participants were screened, with 222 included in the initial analysis. Those who were initially downgraded were more likely to have post-acute shortness of breath (SoB), fatigue and exercise intolerance (objective and subjective), cognitive impairment and report mental health symptoms. The presence of fatigue and SoB, cognitive impairment and mental health symptoms was associated with MDG at 12 months, and the latter two, at 18 months. There were also modest associations between cardiopulmonary function and sustained downgrading. CONCLUSIONS: Understanding the factors that are associated with initial and sustained inability to return to work allows individualized, targeted interventions to be utilized.

Cardiopulmonary exercise testing excludes significant disease in patients recovering from COVID-19.

OBJECTIVE: Post-COVID-19 syndrome presents a health and economic challenge affecting ~10% of patients recovering from COVID-19. Accurate assessment of patients with post-COVID-19 syndrome is complicated by health anxiety and coincident symptomatic autonomic dysfunction. We sought to determine whether either symptoms or objective cardiopulmonary exercise testing could predict clinically significant findings. METHODS: 113 consecutive military patients were assessed in a comprehensive clinical pathway. This included symptom reporting, history, examination, spirometry, echocardiography and cardiopulmonary exercise testing (CPET) in all, with chest CT, dual-energy CT pulmonary angiography and cardiac MRI where indicated. Symptoms, CPET findings and presence/absence of significant pathology were reviewed. Data were analysed to identify diagnostic strategies that may be used to exclude significant disease. RESULTS: 7/113 (6%) patients had clinically significant disease adjudicated by cardiothoracic multidisciplinary team (MDT). These patients had reduced fitness (V̇O2 26.7 (±5.1) vs 34.6 (±7.0) mL/kg/min; p=0.002) and functional capacity (peak power 200 (±36) vs 247 (±55) W; p=0.026) compared with those without significant disease. Simple CPET criteria (oxygen uptake (V̇O2) >100% predicted and minute ventilation (VE)/carbon dioxide elimination (V̇CO2) slope <30.0 or VE/V̇CO2 slope <35.0 in isolation) excluded significant disease with sensitivity and specificity of 86% and 83%, respectively (area under the receiver operating characteristic curve (AUC) 0.89). The addition of capillary blood gases to estimate alveolar-arterial gradient improved diagnostic performance to 100% sensitivity and 78% specificity (AUC 0.92). Symptoms and spirometry did not discriminate significant disease. CONCLUSIONS: In a population recovering from SARS-CoV-2, there is reassuringly little organ pathology. CPET and functional capacity testing, but not reported symptoms, permit the exclusion of clinically significant disease.

Prior sars-cov-2 infection is associated with subclinical changes in the cardiovascular morphology, function, energetics and exercise capacity

Background: COVID-19 has documented multisystem effects. Whether clinically significant cardiac involvement is related to severity of disease in a working age military population remains unknown, but has implications for occupational grading and ability to deploy. Aims: To determine in the military population 1) whether prior SARS-CoV-2 infection causes clinically significant cardiac disease and 2) whether changes are related to disease severity. Methods: 105 military personnel were recruited, 85 with prior SARS-CoV-2 infection (39±10 years, 87% male;50 mild (community), 35 severe (hospitalized) and 20 healthy volunteers (mean age 39 ±8.4 years, 90% male) underwent comprehensive cardiopulmonary investigations including;cardiopulmonary exercise test, exercise echocardiography, cardiac31MRI and P-MR spectroscopy (rest and dobutamine stress). Results: Prior SARS-CoV-2 infection was related to lower VO2max (110±18.2 vs 133±6.7% predicted, p<0.05), anaerobic threshold (45±10 vs 56±14% of peak VO2, p<0.05), VO2/HR (102±21 vs 128±24% predicted, p<0.05) and VE/VCO2 slope (28.3±5.0 vs 25.8±2.7, p<0.05) and an increase in average E/e' change from rest to exercise stress (+1.49±2.4 vs-0.16±3.6, p<0.05). Whilst resting myocardial energetics were similar, prior SARS-CoV-2 infection was associated with a fall in PCr/ATP during stress (by 8%, p=<0.01) which was not seen in healthy controls. When groups were ordered normal> mild> severe disease, RVEDVi, RV stroke volume, VO2peak, VO2pulse and VE/VCO slope were reduced (Jonckheere-Terpstra, all p<0.05). Conclusion: In a young military population, prior SARS-CoV-2 infection is associated with subclinical cardiovascular changes including;lower right ventricular volumes, reduced markers of exercise capacity and reduced myocardial energetics during stress.