Chronic obstructive pulmonary disease (COPD) is the leading indication for lung transplantation worldwide, and the second indication in the U.S. Despite this, a lack of consensus remains regarding the timing and types of transplant surgery.

"One of my goals with [our research] was to educate the pulmonary community on the role of transplant for patients with COPD, both the potential benefits and the potential risks," acknowledged Joshua M. Diamond, co-author of a review recently published in Current Opinion in Pulmonary Medicine

To be eligible for transplant surgery, patients must be placed on a waiting list, which involves a complex algorithm to assess priority. One of the main tools to assess medical urgency is the lung allocation scoring, which is based on age, lung function, body mass index, diabetes, and disease severity. 

Because patients with COPD have a variable disease trajectory, it may be difficult for clinicians to decide when to place a patient on the lung transplant surgery waiting list.

By the time patients get on a waiting list, they are often deemed ineligible because of poor overall health and frailty. Aimee M. Layton et al.sought to determine how frailty influences exercise tolerance.

In a study of 68 patients (mean age, 57 years), frail patients' exercise tolerance was 38 W lower (95% CI, 18.4-58.1 W), and their peak aerobic capacity was 8.5 mL/kg/min lower (95% CI, 3.3-13.7 mL/kg/min), compared with patients who were not frail. Independent of disease severity, frailty contributes to lower exercise tolerance in patients awaiting lung transplants.

"More research is needed to determine if there is a threshold in physical debilitation that predicts a substantial risk [for] perioperative death or complications with the surgery for the listing criteria to change," noted Dr. Layton.

"However, our research helps to provide data that guides such future research to which variables they should be testing to predict such outcomes. Presently, the current listing criteria recommend that patients are enrolled in pulmonary rehabilitation while awaiting lung transplant to improve and maintain a level of physical vigor while awaiting transplant. However, it is questionable how many patients are attending programs and the availability of pulmonary rehabilitation programs."

Although COPD is the leading indication for lung transplantation in the world, and second in the U.S., there is a lack of consensus regarding the timing and type of transplant surgery. Even with the scant evidence available, clinicians need to educate patients with COPD about the benefits and risks of transplant surgery.