Background: Slow heart rate recovery (HRR) after exercise is associated with autonomic dysfunction and increased mortality. What HRR criterion at 1-minute after a 6-minute walk test (6MWT) best defines pulmonary impairment?.
Study Design and Methods: A total of 5008 phase 2 COPDGene (NCT00608764) participants with smoking history were included. A total of 2127 had COPD and, of these, 385 were followed-up 5-years later. Lung surgery, transplant, bronchiectasis, atrial fibrillation, heart failure and pacemakers were exclusionary. HR was measured from pulse oximetry at end-walk and after 1-min seated recovery. A receiver operator characteristic (ROC) identified optimal HRR cut-off. Generalized linear regression determined HRR association with spirometry, chest CT, symptoms and exacerbations.
Results: HRR after 6MWT (bt/min) was categorized in quintiles: ≤5 (23.0% of participants), 6-10 (20.7%), 11-15 (18.9%), 16-22 (18.5%) and ≥23 (18.9%). Compared to HRR≤5, HRR≥11 was associated with (p<0.001): lower pre-walk HR and 1-min post HR; greater end-walk HR; greater 6MWD; greater FEV 1%pred; lower airway wall area and wall thickness. HRR was positively associated with FEV 1%pred and negatively associated with airway wall thickness. An optimal HRR ≤10 bt/min yielded an area under the ROC curve of 0.62 (95% CI 0.58-0.66) for identifying FEV 1<30%pred. HRR≥11 bt/min was the lowest HRR associated with consistently less impairment in 6MWT, spirometry and CT variables. In COPD, HRR≤10 bt/min was associated with (p<0.001): ≥2 exacerbations in the previous year (OR=1.76[1.33-2.34]); CAT≥10 (OR=1.42[1.18-1.71]); mMRC≥2 (OR=1.42[1.19-1.69]); GOLD 4 (OR=1.98[1.44-2.73]) and GOLD D (OR=1.51[1.18-1.95]). HRR≤10 bt/min was predicted COPD exacerbations at 5-year follow-up (RR=1.83[1.07-3.12], P=0.027).
Conclusion: HRR≤10 bt/min after 6MWT in COPD is associated with more severe expiratory flow limitation, airway wall thickening, worse dyspnoea and quality of life, and future exacerbations, suggesting that an abnormal HRR≤10 bt/min after a 6MWT may be used in a comprehensive assessment in COPD for risk of severity, symptoms and future exacerbations.
Bibliographical noteFunding Information:
The COPDGene study is supported by grants from the National Heart, Lung, and Blood Institute (NIH/NHLBI R01HL089897, R01HL089856 [(Rossiter, Adami], U01HL089897, U01HL089856 [(Crapo, Silverman; COPDGene]).
Asghar Abbasi is supported by a postdoctoral fellowship from the Tobacco-Related Disease Research Program (28FT-0017).
Barry Make reports (related to the general topic of COPD over the last three years) grants from NHLBI, Pearl Research, Circassia, GlaxoSmithKline and AstraZeneca; advisory board fees from GlaxoSmithKline, AstraZeneca, Boehringer Ingelheim, Verona, Third Pole, and Phillips; consulting fees from AstraZeneca; medical board member, grants, non-financial support, grant funds provided to and controlled by National Jewish Health for/ from Astra Zeneca, grants and CME activity for/from Glaxo Smith Kline, CME activity for Wolters Kluwer Health, Spiration, CME activity for Sunovion, Mt Sinai, Web MD, National Jewish Health, Novartis, American College of Chest Physicians, Projects in Knowledge, Hybrid Communications, Medscape, Ultimate Medical Academy, Eastern Pulmonary Society, Catamount Medical, Eastern VA Medical Center, and Academy Continued Health Care Learning, grants from Pearl Research (funds provided to and controlled by National Jewish Health), medical advisory board for Verona, Boehringer Ingelheim, Theravance, Phillips, and Science 24/7, non-financial support from Circassia, personal fees from Third Pole and Takeda, and grants from NHLBI, outside the submitted work. Russ Bowler has no disclosures to report.
Harry Rossiter is supported by grants from NIH (R01HL151452, P50HD098593, R01DK122767, P2CHD086851) and the Tobacco Related Disease Research Program (T31IP1666). He reports consulting fees from Omniox Inc., and is involved in contracted clinical research with Boehringer Ingelheim, GlaxoSmithKline, Novartis, AstraZeneca, Astellas, United Therapeutics, Genentech and Regeneron.
Nicholas B. Tiller is supported by a postdoctoral fellowship from the Tobacco-Related Disease Research Program (T31FT1692). Wei Yuan has no disclosures to report. Christopher Yee has no disclosures to report.
Alessandra Adami is supported by a grant from NIH/ NHLBI (R01HL151452).
© 2021 Zhao et al.
- COPD exacerbation
- autonomic dysfunction
- chest computed tomography
- Forced Expiratory Volume
- Pulmonary Disease, Chronic Obstructive/diagnosis
- Heart Rate
- Quality of Life
- Walk Test
PubMed: MeSH publication types
- Journal Article