Effects of heart failure on cerebral blood flow in COPD: Rest and exercise

Cerebral blood flow (CBF) and oxygenation (COx) are generally well-preserved in COPD. It is unknown whether prevalent cardiovascular co-morbidities, such as heart failure, may impair CBF and COx responses to exertion. Eighteen males with moderate-to-severe COPD (8 with and 10 without overlapping heart failure) underwent a progressive exercise test with pre-frontal CBF and COx measurements (indocyanine green and near-infrared spectroscopy). Mean arterial pressure and cardiac output were lower from rest to exercise in overlap. Only COPD patients demonstrated an increase in arterialized PCO2 towards the end of progressive exercise. CBF index was consistently higher and increased further by ∼40% during exercise in COPD whereas a ∼10% reduction was observed in overlap. COx was lower in overlap despite preserved arterial oxygenation. In conclusion, heart failure introduces pronounced negative effects on CBF and COx in COPD which may be associated with clinically relevant outcomes, including dyspnea, exercise intolerance, cerebrovascular disease and cognitive impairment.