Left ventricular diastolic dysfunction and exertional ventilatory inefficiency in COPD

• Published in: Respiratory medicine 2018-12, Vol.145, p.101-109
• Main Authors: Muller, Paulo T., Utida, Karina A.M., Augusto, Tiago R.L., Spreafico, Marcos V.P., Mustafa, Reiby C., Xavier, Ana W., Saraiva, Erlandson F.
• Format: Article
• Language: English
• Subjects: Aerobic capacity; Airway management; Carbon dioxide; Chronic obstructive pulmonary disease; Coronary artery disease; Doppler effect; Echocardiography; Exercise; Heart; Heart diseases; Left ventricular diastolic dysfunction; Lungs; Mechanical ventilation; Metabolism; Outpatient care facilities; Physical fitness; Pressure; Respiratory function; Subgroups; Variability; Ventilation; Ventricle
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2018.10.014

Left ventricular diastolic dysfunction (LVDD) is highly prevalent in COPD and conflicting results have emerged regarding the consequences on exercise capacity in the 6MWT. We sought to examine the ventilatory efficiency and variability metrics as the primary endpoint and aerobic capacity (V'O2) as the secondary endpoint. Forty subjects were included and submitted to comprehensive lung function tests, detailed pulsed-Doppler echocardiography, and cardiopulmonary exercise testing. Four subjects were excluded due to concomitant cardiac disease and two owing to COPD exacerbation. Seventeen COPD/LVDD+ and seventeen COPD/LVDD-individuals were closely matched for baseline characteristics. Throughout the exercise, there was no difference between-groups for primary (V'E/V'CO2slope and V'E/V'CO2nadir, p > 0.05 for both) or secondary endpoints (V'O2peak%pred, p > 0.05). Ventilatory variability remained unchanged. However, after very well age- and sex-matched subgroup analysis, five-moderate and three-mild COPD/LVDD + subjects with elevated left ventricular filling pressure (E/e'>13, n = 8), presented a downward-shifted V'E/V'CO2slope (25.7 ± 5.1 vs 33.4 ± 7.1, p = 0.031) and V'E/V'CO2nadir reduction (29.7 ± 3.9 vs 36.3 ± 7.2, p = 0.042) besides significantly better V'O2peak%pred (92.1 ± 21.6% vs 75.8 ± 13.1%, p = 0.045) compared to 8 COPD/LVDD-controls. Ventilatory variability remained once again unchanged. COPD/LVDD overlap is not associated with worse exercise tolerance and/or wasted ventilation in excess compared to controls, even when suspected for elevated left ventricular filling pressure. Further studies are warranted to study specifically if augmented pulmonary blood transit time can allow better gas-exchange, thus preserving exercise capacity under specific conditions in COPD patients without heart failure. •We evaluate the association of LV diastolic dysfunction and COPD related to exertional ventilatory inefficiency and variability.•We found similar ventilatory efficiency and variability metrics for the association compared to controls.•COPD with moderately increase in LV filling pressure, however, warrant more studies for gas-exchange and ventilatory efficiency metrics.