More Questions Than Answers

When I was in medical school, about a decade ago, I learned about chronic obstructive pulmonary disease (COPD) essentially as a dichotomous disease of "pink puffers" and "blue bloaters"—disparaging terms which were meant to represent the spectrum of disease from emphysema to chronic bronchitis. The oversimplification is increasingly obvious; over the past decade, the understanding of COPD has reached the point that using the term "COPD" is arguably as unhelpful as describing patients as broadly having "anemia." Not only do patients with COPD fall on a spectrum from emphysema to chronic bronchitis, but a significant number of them have bronchiectasis and many have an overlapping component of type 2 inflammation or asthma. This subphenotyping is not just semantic: Patients with different characteristics of the disease spectrum respond differently to therapy (1), an observation now reflected in the 2023 guidelines from the Global Initiative for Chronic Obstructive Lung Disease.

As an academic pulmonologist, I regularly see patients as a second or third opinion. In an effort to develop a treatment plan most personalized to their disease phenotype, I do my best to accurately characterize those who have been labeled as having "COPD" more precisely. But the more I try to do this, the murkier things become. For example, take the recent article published in Annals by Diaz and colleagues (2). This large study showed not only that patients with COPD–bronchiectasis overlap have increased mortality (this was previously known), but that patients who have radiographic COPD–bronchiectasis have increased mortality as well, even if their pulmonary function testing is normal.

What do I tell my patients? COPD is a diagnosis based and staged on spirometry. Patients with normal spirometry do not technically have COPD—but clearly this is untrue for a significant number of people, since they have clinical manifestations consistent with chronic obstructive lung disease and radiographic evidence of bronchiectasis in combination with emphysema and/or chronic bronchitis. More to the point of what patients and their families care about, this diagnosis that they technically do not have is convincingly associated with increased mortality. And, finally, consider that pulmonary rehabilitation programs, already underutilized despite clearly demonstrated benefits in COPD (3), are often not approved by insurance if patients do not have spirometric obstruction.

Thus a resident's or fellow's presentation of a "straightforward COPD patient" becomes a nuanced and complicated discussion, and the 45 to 60 minutes allotted to a new clinic patient becomes woefully inadequate. And, despite my best efforts at providing clarity, I'm afraid that the trainees with me that day (and perhaps my patients) leave the clinic with more questions than answers.

References

1. Ritchie AI, Singayagam A, Mitchell S, et al. The effect of inhaled corticosteroids on pneumonia risk in patients with COPD-bronchiectasis overlap: a UK population-based case-control study. Chest. 2023;164:875-884. [PMID: 37419145] doi:10.1016/j.chest.2023.06.007
2. Diaz AA, Wang W, Orejas JL, et al. Suspected bronchiectasis and mortality in adults with a history of smoking who have normal and impaired lung function. A cohort study. Ann Intern Med. 2023;176:1340-1348. [PMID: 37782931] doi:10.7326/M23-1125
3. Lindenauer PK, Stefan MS, Pekow PS, et al. Association between initiation of pulmonary rehabilitation after hospitalization for COPD and 1-year survival among Medicare beneficiaries. JAMA. 2020;323:1813-1823. [PMID: 32396181] doi:10.1001/jama.2020.4437

Yuri Matusov, MD

Yuri Matusov, MD, is an assistant professor of medicine in the Division of Pulmonary and Critical Care Medicine at Cedars-Sinai Medical Center in Los Angeles. He trained in internal medicine at Santa Barbara Cottage Hospital and completed PCCM fellowship at Cedars-Sinai. His research and clinical interests are in pulmonary vascular disease and right ventricular failure in pulmonary hypertension, parenchymal lung disease, and ARDS. He is an Annals editorial fellow for the 2023–2024 academic year.