CVD Is Biggest Mortality Cause in COPD, Especially Among Black Patients

Black patients with COPD had higher rates of cardiovascular disease than White patients, while mortality from infection and cancer were similar.

In patients with chronic obstructive pulmonary disease (COPD), the management of cardiovascular disease (CVD) comorbidities, particularly among Black individuals, may help in improving mortality outcomes, according to results of an analysis published in Annals of the American Thoracic Society

Race- and sex-based differences in all-cause mortality and cause-specific mortality have not been well described in patients with COPD. Researchers therefore researchers sought to explore the mortality differences in COPD by race and sex, as well as by underlying mechanisms. The investigators used Medicare claims to identify the presence of COPD among individuals participating in Reasons for Geographic and Racial Differences in Stroke (REGARDS), a national, prospective, observational, longitudinal cohort study involving 30,239 individuals at least 45 years of age residing within the continental US.

The primary study outcome was all-cause mortality. Secondary outcomes included cause-specific mortality from CVD, chronic lung disease, infection, or cancer. 

The current analysis included 2148 participants from the REGARDS study with Medicare claims data showing evidence of COPD. The makeup of this group by race/sex was: 14% Black men; 37% White men; 20% Black women; and 29% White women. The mean (SD) participant age was 71.8 (7.7) years.

Over a median 7.5 years of follow-up (range, 3.9 to 10.5 years), a total of 1326 deaths were reported. Age-adjusted all-cause mortality per 1000 person-years was 85.4
(95% CI, 77.7 to 93.9) among Black participants and 83.1 (95% CI, 77.7 to 88.9; P =.65) among White participants.  

The age-adjusted mortality per 1000 person-years was 101.1 (95% CI, 88.3 to 115.8) among Black men, 93.9 (95% CI, 86.3 to 102.3) among White men, 74.2 (95% CI, 65.0 to 84.8) among Black women, and 70.6 (95% CI, 63.5 to 78.5) among White women
(P value for Black vs White men, 0.99; P value for Black vs White women, 0.99).

Additionally, the age- and region-adjusted hazard ratio (HR) for mortality among Black men vs White men was 1.06 (95% CI, 0.90 to 1.25), and the HR for mortality among Black women vs White women 1.08 (95% CI, 0.91 to 1.28). Based on fully adjusted models, the HR for mortality in Black men vs White men was 0.89 (95% CI, 0.74 to 1.05); in Black women vs White women, the HR was 0.94 (95% CI, 0.78 to 1.14).

CVD was the largest cause of mortality among all of the COPD race-sex groups evaluated. Age-adjusted CVD mortality per 1,000 person-years was 30.9 for Black men (95% CI, 24.2–39.5) vs 28.3 for White men (95% CI, 24.3–33.1) (P value for difference, 0.99) and 25.4 for Black women (95% CI, 20.2–31.9) vs 18.7 for White women (95% CI, 15.2–22.9) (P value for difference 0.3).

Our findings call for further research in large samples to examine race-sex group differences in cause-specific mortality. They also suggest that increasing longevity in patients with COPD may require increased focus on CVD comorbidity management, especially among Black individuals.

Chronic lung disease mortality per 1000 person-years was 11.0 in Black men (95% CI, 7.3 to 16.6) vs 12.0 (95% CI, 9.4 to 15.2) in White men (P value for difference, 0.99). Chronic lung disease mortality per 1000 person-years was significantly lower among Black women (5.7; 95% CI, 3.6 to 9.3) than among White women (13.2; 95% CI, 10.4 to 16.9; P =.01).  Mortality rates for infection and cancer were largely similar between both Black and White men and Black and White women.

Several limitations of the current study should be noted. The COPD cohort was defined with use of a Medicare claims-based algorithm — a method that is subject to errors in omission and misclassification. Further, the REGARDS study did not obtain participants’ spirometry at baseline.

According to the authors, “Our findings call for further research in large samples to examine race-sex group differences in cause-specific mortality. They also suggest that increasing longevity in patients with COPD may require increased focus on CVD comorbidity management, especially among Black individuals.”

Author disclosures are available with the text of this article at www.atsjournals.org.

References:

Krishnan JK, Rajan M, Banerjee S, et al. Race and sex differences in mortality in individuals with chronic obstructive pulmonary disease. Ann Am Thorac Soc. 2022;19(10):1661-1668. doi:10.1513/AnnalsATS.202112-1346OC