Abstract
Anecdotal evidence suggests that patients with COPD who present with heart failure and reduced left ventricular ejection fraction (HFrEF) have poorer functional performance than their counterparts with COPD in isolation. However, no previous study has prospectively contrasted the physiological and subjective responses of COPD+HFrEF and COPD matched by the severity of airflow obstruction. Forty-four males with COPD+HFrEF and 52 age-matched patients with COPD underwent an incremental cardiopulmonary exercise test. Peak exercise capacity was significantly reduced in COPD+HFrEF. This was associated with increased sub-maximal ventilatory responses and less oxy-hemoglobin desaturation (p<0.05). These patients also showed less exercise-induced decrements in inspiratory capacity; in fact, ventilation-corrected EILV/TLC values were lower in these patients. In contrast to COPD the dominant locus of symptom limitation in COPD+HFrEF was increased leg effort (Table).
Table. Resting characteristics and responses to incremental exercise.
* p<0.05
In conclusion, excessive exercise ventilatory responses in COPD+HFrEF than FEV1-matched COPD patients were not translated into greater breathlessness scores as the former group showed less ventilatory constraints and hypoxemia. These results suggest that other mechanisms (e.g., cardiovascular, peripheral) are more relevant for worsening exercise capacity in COPD+HFrEF.
- © 2014 ERS