Effect of high-intensity exercise on cerebral, respiratory and peripheral muscle oxygenation of HF and COPD-HF patients

Objective: To investigate cerebral oxygenation (Cox) responses as well as respiratory (Res) and active peripheral muscle (Pm) O-2 delivery during high-intensity cycling exercise and contrast responses between patients with coexistent chronic obstructive pulmonary disease (COPD)-heart failure (HF) and HF alone. Methods: Cross-sectional study involving 11 COPD-HF and 11 HF patients. On two different days, patients performed maximal incremental cardiopulmonary exercise testing (CPET) and constant load exercise on a cycle ergometer until the limit of tolerance (Tlim). The high-intensity exercise session was 80% of the peak CPET work rate. Relative blood concentrations of oxyhemoglobin ([O(2)Hb]), deoxyhemoglobin ([HHb]) of Res, Pm (right vastus lateralis) and Cox (pre-frontal) were measured using near infrared spectroscopy. Results: We observed a greater decrease in [O(2)Hb] at a lower Tlim in COPD-HF when compared to HF (P < 0.05). [HHb] of Res was higher (P < 0.05) and Tlim was lower in COPD-HF vs. HF. Pm and Cox were lower and Tlim was higher in (P < 0.05) HF vs. COPD-HF. In HF, there was a lower Delta[O(2)Hb] and higher A [HHb] of Pm when contrasted to Cox observed during exercise, as well as a lower Delta[O(2)Hb] and higher Delta [HHb] of Res when contrasted with Cox (P < 0.05). However, COPD-HF patients presented with a higher Delta [HHb] of Res and Pm when contrasted with Cox (P < 0.05). Conclusion: The coexistence of COPD in patients with HF produces negative effects on Cox, greater deoxygenation of the respiratory and peripheral muscles and higher exertional dyspnea, which may help to explain an even lower exercise tolerance in this multimorbidity phenotype. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

This study investigated the differences in cerebral oxygenation, respiratory and muscle oxygen delivery during high-intensity cycling exercise between COPD-HF patients and HF patients. The results showed that COPD-HF patients had poorer cerebral oxygenation and higher deoxygenation in respiratory and peripheral muscles, leading to higher exertional dyspnea and lower exercise tolerance compared to HF patients. These findings suggest that the coexistence of COPD in patients with HF may have negative effects on exercise performance.