Evaluation of the Usefulness of Adopting Remote, Mobile-based 6MWT Among Hospital Outpatients (the 6-APPnow), Within the Constraints Imposed by the SARS-COV2 Pandemic

Context:

Since the outbreak of SARS-CoV-2, health care systems have been subject to increased pressures. This is mainly due to infected patients being admitted to the medical wards and intensive care units, but also due to the requirement to reduce exposure of both healthcare professionals and patients to COVID by minimising contact. There are indications that reduced access to healthcare services during the pandemic is responsible for more than half of excess deaths in the United States. In response to this, the CDC is advocating the use of telemedicine to keep providing a remote version of healthcare services. A study of telemedicine services in China used during COVID-19 pandemic showed that they reduced burden on hospitals, prevented overcrowding, reduced the risk of cross-infection, and relieved patients' anxiety. The use of telemedicine is also being developed in Europe, where many patients are being denied the use of clinical services, like cardiac rehabilitation, because of centres being closed. In the context of the NHS, an increased use of telemedicine services is being observed. The NHS long-term plans do, in fact, include tele-consultations as a pillar for its sustainability. Healthwatch have produced useful advice for outpatient clinicians to consider avoiding asking patients to attend physical outpatient appointments where a clinically-appropriate and accessible alternative exists. Where an appointment is clinically necessary, the national benchmark is that at least 25% could be conducted by telephone or video including 60% of all follow-up appointments. Initial promising results are being seen in the context of diabetes, where virtual clinics are recommended as mitigation to the pandemic.

The 6MWT:

To assess patient's exercise capacity, the six-minute walk test (6MWT) is a standard method used in patients with cardiopulmonary disease such as Heart Failure (HF) or Pulmonary arterial Hypertension (PAH). The 6MWT measures how far a patient can walk in 6 minutes. Walking is an activity performed every day, by most patients except for those most severely limited. By assessing patients' ability to exercise, the 6MWT provides a global assessment of respiratory, cardiovascular, neuromuscular and cognitive function. The 6MWT does not differentiate what limits the patient, nor does it assess maximal exercise capacity. Instead, the 6MWT allows the patient to exercise at a daily functional level, and is a useful tool for assessing changes after a therapeutic intervention, and correlates with a subjective improvement in dyspnoea.

In PAH the 6MWT is used to evaluate patients' response to treatment, with an increase in 6MWT distance of greater than 42 m being considered a clinically significant improvement . Furthermore, change in 6MWT distance correlates with VO2 max, NYHA class and mortality in those patients, providing an objective assessment of disease progression, prognosis and response to treatment. It is a universally accepted test as it is safe and easily performed by the patient.