Pulmonary Rehabilitation Improves Cardiovascular Response to Exercise in COPD

Background: Pulmonary rehabilitation (PR) has emerged as a recommended standard of care in symptomatic COPD. Objectives: We now studied whether PR may affect cardiovascular response to exercise in these patients. Methods: Twenty-seven patients (9 females aged 69 ± 8 years) with moderate-to-severe airflow obstruction admitted to a 9-week PR course performed a pre-to-post evaluation of lung function test and symptom-limited cardiopulmonary exercise test (CPET). Oxygen uptake (VO₂), tidal volume (VT), dyspnea and leg fatigue scores were measured during CPET. Cardiovas-cular response was assessed by means of oxygen pulse (O₂Pulse), the oxygen uptake efficiency slope and heart rate recovery at the 1st min. Results: A significant increase in peak VO₂ and in all cardiovascular parameters (p < 0.05) was found following PR when compared to baseline. Leg fatigue (p < 0.05), but not dyspnea, was significantly reduced after PR. When assessed at metabolic and ventilatory iso levels [% VCO₂max and % minute ventilation (VEmax)], O₂Pulse and VT were significantly higher (p < 0.05) at submaximal exercise (75 and 50% of VCO₂max and VEmax) after PR when compared to baseline. VT percent changes at 75% VCO₂max and 75% VEmax after PR significantly correlated with corresponding changes in O₂Pulse (p < 0.01). Conclusions: In COPD patients, a PR training program improved the cardiovascular response during exercise at submaximal exercise independent of the external workload. This change was associated with an enhanced ventilatory function during exercise.