The Exercise Response to Pharmacologic Cholinergic Stimulation in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome

• Status: Enrolling by invitation
• Trial end date: 2021-06-01
• Target enrollment: 0
• Participant gender: All

Summary

Myalgic encephalomyelitis/Chronic fatigue syndrome (ME/CFS), otherwise known as Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME), is an under-recognized disorder whose cause is not yet understood. Suggested theories behind the pathophysiology of this condition include autoimmune causes, an inciting viral illness, and a dysfunctional autonomic nervous system caused by a small fiber polyneuropathy. Symptoms include fatigue, cognitive impairments, gastrointestinal changes, exertional dyspnea, and post-exertional malaise. The latter two symptoms are caused in part by abnormal cardiopulmonary hemodynamics during exercise thought to be due to a small fiber polyneuropathy. This manifests as low biventricular filling pressures throughout exercise seen in patients undergoing a level 3 CPET along with small nerve fiber atrophy seen on skin biopsy.

After diagnosis, patients are often treated with pyridostigmine (off-label use of this medication) to enhance cholinergic stimulation of norepinephrine release at the post-ganglionic synapse. This is thought to improve venoconstriction at the site of exercising muscles, leading to improved return of blood to the heart and increasing filling of the heart to more appropriate levels during peak exercise. Retrospective studies have shown that noninvasive measurements of exercise capacity, such as oxygen uptake, end-tidal carbon dioxide, and ventilatory efficiency, improve after treatment with pyridostigmine. To date, there are no studies that assess invasive hemodynamics after pyridostigmine administration.

It is estimated that four million people suffer from ME/CFS worldwide, a number that is thought to be a gross underestimate of disease prevalence. However, despite its potential for debilitating symptoms, loss of productivity, and worldwide burden, the pathophysiology behind ME/CFS remains unknown and its treatment unclear. By evaluating the exercise response to cholinergic stimulation, this study will shed further light on the link between the autonomic nervous system and cardiopulmonary hemodynamics, potentially leading to new therapeutic targets.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Brigham and Women's Hospital
• Treatments: Bromides; Cholinergic Agents; Pyridostigmine Bromide

Criteria

Inclusion Criteria:

• Meets the Institute of Medicine (IOM) criteria for ME/CFS

• Completing the clinically indicated iCPET

Exclusion Criteria:

• Obesity (BMI > 30 kg/m2)

• Non-controlled asthma

• Anemia (Hb < 10 g/dl)

• Active or treated cancer

• History of interstitial lung disease (ILD)

• Chronic obstructive pulmonary disease (COPD)

• Pulmonary hypertension (PH)

• Congestive heart failure (CHF)

• Active arrhythmias

• Valvular heart disease

• Coronary artery disease (CAD)

• Other conditions that could predict a limitation or not completion of the study.

• Pregnancy

• Submaximal testing in clinically indicated iCPET

• Pulmonary mechanical limitation to exercise in clinically indicated iCPET.

• Pulmonary arterial hypertension in clinically indicated iCPET.

• Pulmonary venous hypertension in clinically indicated iCPET.

• Exercise induced pulmonary arterial hypertension in clinically indicated iCPET.

• Exercise induced pulmonary venous hypertension in clinically indicated iCPET.

• Persistent hypotension during or after the clinically indicated iCPET.

• Refractory arrhythmia during or after the clinically indicated level 3 CPET.