Exercise Ventilation in COPD: Influence of Systolic Heart Failure

Abstract

Systolic heart failure is a common and disabling co-morbidity of chronic obstructive pulmonary disease (COPD) which may increase exercise ventilation due to heightened neural drive and/or impaired pulmonary gas exchange efficiency. The influence of heart failure on exercise ventilation, however, remains poorly characterized in COPD. In a prospective study, 98 patients with moderate to very severe COPD [41 with coexisting heart failure; 'overlap' (left ventricular ejection fraction < 50%)] underwent an incremental cardiopulmonary exercise test (CPET). Compared to COPD, overlap had lower peak exercise capacity despite higher FEV. Overlap showed lower operating lung volumes, greater ventilatory inefficiency and larger decrements in end-tidal CO (PETCO) (P < 0.05). These results were consistent with those found in FEV-matched patients. Larger areas under receiver operating characteristic curves to discriminate overlap from COPD were found for ventilation ([Formula: see text]E)-CO output [Formula: see text]CO) intercept, [Formula: see text]E-[Formula: see text]CO slope, peak [Formula: see text]E/[Formula: see text]CO ratio and peak PETCO. Multiple logistic regression analysis revealed that [Formula: see text]CO intercept ≤ 3.5 L/minute [odds ratios (95% CI) = 7.69 (2.61-22.65), P < 0.001] plus [Formula: see text]E-[Formula: see text]CO slope ≥ 34 [2.18 (0.73-6.50), P = 0.14] or peak [Formula: see text]E/[Formula: see text]CO ratio ≥ 37 [5.35 (1.96-14.59), P = 0.001] plus peak PETCO ≤ 31 mmHg [5.73 (1.42-23.15), P = 0.01] were indicative of overlapping. Heart failure increases the ventilatory response to metabolic demand in COPD. Variables reflecting excessive ventilation might prove useful to assist clinical interpretation of CPET responses in COPD patients presenting heart failure as co-morbidity.

Exertional dyspnoea in COPD: the clinical utility of cardiopulmonary exercise testing

“…Full pulmonary function tests (spirometry, lung volume components including IC, diffusing capacity of the lung and resting arterial O 2 saturation) are also a prerequisite. Documentation of comorbidities potentially associated with exertional dyspnoea (obesity [73][74][75][76], cardio-circulatory disorders [77][78][79], anaemia, etc.) is also essential for proper CPET interpretation.…”

Effects of high- and moderate-intensity exercise on central hemodynamic and oxygen uptake recovery kinetics in CHF-COPD overlap

“…VCO 2 slope is a hallmark of more severe CHF (32) and in the presence of COPD comorbidity, the expected alterations in lung function further worsen the ventilation-perfusion mismatch in the lungs and the ventilatory efficiency in CHF patients (3). In fact, the results of a recent study indicated that lower maximal exercise capacity in CHF-COPD patients was associated with greater ventilatory inefficiency, attenuated dynamic hyperinflation and lower peak P ET CO 2 compared to patients with COPD alone (33). Thus, our data suggested that the poorer ventilatory efficiency in CHF-COPD patients also reflected impaired .…”

The Value of Cardiopulmonary Exercise Testing in Determining Severity in Patients with both Systolic Heart Failure and COPD

“…There is an increasing recognition that exercise intolerance in overlap of HF-COPD cases may be associated with increased ventilatory responses due to metabolic demand, resulting in ventilatory inefficiency 9,10 . This varies considerably in patients with HF-COPD with pulmonary involvement [Forced Expiratory Volume in the first second (FEV 1 )] and cardiac [left ventricular ejection fraction (LVEF)] [11][12][13] . However, the structural and physiological determinants that support this great variability remain poorly understood.…”

“…In addition, the studies that performed CPET focused on the variation between different populations presented as main objective the comparison with tests [10][11][12]19,20 . Thus, there is no information about the impact of HF-COPD on CPET variables, since these patients have marked ventilatory and cardiac limitations and, from a clinical point of view, established cut-off values for these patients based on the disease severity.…”