HElping Alleviate the Longer-term Consequences of COVID-19 (HEAL-COVID): a National Platform Trial

BACKGROUND: In December 2019, a cluster of patients with pneumonia of unknown cause was described in Wuhan, China. Named SARS-CoV-2 due to its resemblance to the coronavirus responsible for severe acute respiratory syndrome (SARS-CoV), COVID-19 is the infectious disease caused by SARS-CoV-2. Despite historically unprecedented public health measures, SARS-CoV-2 has rapidly spread across the world. The World Health Organisation (WHO) declared the COVID-19 outbreak a public health emergency of international concern on 30th January 2020.

The acute effects of COVID-19 are now well described. Evidence is emerging of serious longer-term complications occurring in the convalescent phase of the illness in a significant proportion of patients. COVID-19 is a new disease, the natural history of which remains uncertain. Recent data highlight that ~20% of patients develop new or worsened cardiopulmonary symptoms at 40-60-days after hospital discharge. A unique feature of COVID-19 is the high incidence of these cardiovascular and pulmonary complications that may carry long-term implications for morbidity and mortality including venous thromboembolism, persistent lung inflammation, and pulmonary fibrosis; increasingly it appears these may not be confined to the acute phase of the illness, but rather may also occur during the convalescent phase of the illness, thus providing a major contribution to the ill-defined syndrome "Long COVID".

"Long COVID" is likely to include a constellation of different conditions traversing post-ICU syndromes, significant cardiopulmonary complications, post-viral syndromes and exacerbations of underlying conditions. Patients have reported a range of long-term symptoms associated with Long COVID that have significant impact on their quality of life. Though there have been effective acute treatments, there has been little work evaluating longer-term treatment aimed at reducing longer-term complications. To investigate the role of medium-term convalescent treatment targeting known and emerging complications, an adaptive platform trial will enrol patients at the point of hospital discharge from across centres in the UK.

OBJECTIVES: HEAL-COVID is an adaptive platform trial design to provide reliable evidence on the efficacy of post-hospitalisation treatments to improve longer-term clinical outcomes from COVID-19.

In early 2021, when the trial commenced, there were no treatments being assessed in randomised controlled trials targeting the post-hospital phase of COVID-19. Longer-term outcomes for COVID-19 are currently unclear, but early data suggest a significant burden of mortality and morbidity. In this situation, even treatments with only a moderate impact on survival or on hospital resource use are worthwhile. Therefore, the focus of HEAL-COVID is the impact of candidate treatments on mortality and the need for rehospitalisation.