Association between post-exercise heart rate recovery and one-year clinical deterioration in COPD: a retrospective longitudinal analysis

The application of cardiopulmonary exercise testing (CPET) for assessing heart rate recovery at 1 min (HRR1) is of significant clinical value in evaluating disease severity, cardiovascular risk, and prognosis in patients with cardiovascular diseases. However, its utility in patients with stable chronic obstructive pulmonary disease (COPD) is still understudied. To investigate the associations of abnormal HRR1 with Pulmonary Function Test (PFT), modified Medical Research Council (mMRC) dyspnea scale, COPD Assessment Test (CAT) score, systemic inflammatory markers, as well as acute exacerbations of COPD (AECOPD) during a 1-year follow-up in patients with stable COPD. This retrospective study analyzed clinical data from 90 patients with stable COPD attending the outpatient clinic of the Department of Respiratory and Critical Care Medicine at China-Japan Friendship Hospital from January 2021 to October 2025. Abnormal HRR1 post-CPET was defined as ≤ 12 beats/min. Patients were then categorized into normal (HRR1 > 12 beats/min) and abnormal (HRR1 ≤ 12 beats/min) groups accordingly. We compared clinical parameters between the two groups and performed multivariable regression analysis to identify independent indicators of adverse outcomes. During the one-year follow-up, patients with abnormal HRR1 exhibited a clinically significant deterioration, including a median increase of 2 points in CAT score, a decline in FEV1 by 110 ml, and a reduction in FEV1pred by 3.656%. Additionally, 68.9% of patients experienced at least one AECOPD. Multivariable regression analysis revealed that HRR1 was an independent indicator of AECOPD and CAT score elevation. Specifically, compared with patients with normal HRR1, those with baseline HRR1 ≤ 12 beats/min exhibited 3.224-fold higher odds o f subsequent AECOPD and 1.020-fold higher odds o f CAT score worsening. This study suggests that HRR1 is associated with airflow limitation, exercise capacity, and systemic inflammation in patients with stable COPD. Furthermore, HRR1 served as an independent indicator of AECOPD and CAT score elevation. A baseline HRR1 cutoff of ≤ 12 beats/min was associated with an increased risk of adverse outcomes and greater symptom burden, supporting its potential utility in identifying patients who may benefit from close clinical monitoring.