Proportional Assist Ventilation Improves Leg Muscle Reoxygenation After Exercise in Heart Failure With Reduced Ejection Fraction

Exercise oscillatory ventilation in patients with coexisting chronic obstructive pulmonary disease and heart failure: Clinical implications

BACKGROUND

Exercise oscillatory ventilation (EOV) is considered an important variable for predicting poor prognosis in patients with heart failure (HF) with reduced left ventricular ejection fraction (HFrEF). However, there are no studies evaluating EOV presence in the coexistence chronic obstructive pulmonary disease (COPD) and HFrEF.

AIMS

I) To compare the clinical characteristics of participants with coexisting HFrEF-COPD with and without EOV during cardiopulmonary exercise testing (CPET); and II) to identify the impact of EOV on mortality during follow-up for 35 months.

METHODS

50 stable HFrEF-COPD (EF<50%) participants underwent CPET and were followed for 35 months. The parametric Student's t-test, chi-square tests, linear regression model and Kaplan-Meier analysis were applied.

RESULTS

We identified 13 (26%) participants with EOV and 37 (74%) without EOV (N-EOV) during exercise. The EOV group had worse cardiac function (LVEF: 30 ± 6% vs. N-EOV 40 ± 9%, p = 0.007), worse pulmonary function (FEV1: 1.04 ± 0.7 L vs. N-EOV 1.88 ± 0.7 L, p = 0.007), a higher mortality rate [7 (54%) vs. N-EOV 8 (27%), p = 0.02], higher minute ventilation/carbon dioxide production (V̇˙E/ V̇˙ CO2) slope (42 ± 7 vs. N-EOV 36 ± 8, p = 0.04), reduced peak ventilation (L/min) (26.2 ± 16.7 vs. N-EOV 40.3 ± 16.4, p = 0.01) and peak oxygen uptake (mlO2 kg-1 min-1) (11.0 ± 4.0 vs. N-EOV 13.5 ± 3.4 ml●kg-1●min-1, p = 0.04) when compared with N-EOV group. We found that EOV group had a higher risk of mortality during follow-up (long-rank p = 0.001) than patients with N-EOV group.

CONCLUSION

The presence of EOV is associated with greater severity of coexisting HFrEF and COPD and a reduced prognosis. Assessment of EOV in participants with coexisting HFrEF-COPD, as a biomarker for both clinical status and prognosis may therefore be warranted.

Non-invasive ventilatory support accelerates the oxygen uptake and heart rate kinetics and improves muscle oxygenation dynamics in COPD-HF patients

BACKGROUND

The aim of this study was to explore the effects of non-invasive positive pressure ventilation (NIPPV) associated with high-intensity exercise on heart rate (HR) and oxygen uptake (V̇O₂) recovery kinetics in in patients with coexistence of chronic obstructive pulmonary disease (COPD) and heart failure (HF).

METHODS

This is a randomized, double blinded, sham-controlled study involving 14 HF-COPD patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NIPPV (bilevel mode - Astral 150) in a random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin and deoxyhemoglobin were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, Netherland).

RESULTS

The kinetic variables of both V̇O₂ and HR during the high-intensity constant workload protocol were significantly faster in the NIPPV protocol compared to Sham ventilation (P<0.05). Also, there was a marked improvement in oxygenation and lower deoxygenation of both peripheral and respiratory musculature in TLim during NIPPV when contrasted with Sham ventilation.

CONCLUSIONS

NIPPV applied during high-intensity dynamic exercise can effectively improve exercise tolerance, accelerate HR and V̇O₂ kinetics, improve respiratory and peripheral muscle oxygenation in COPD-HF patients. These beneficial results from the effects of NIPPV may provide evidence and a basis for high-intensity physical training for these patients in cardiopulmonary rehabilitation programs.

The Need for Breathing Training Techniques: The Elephant in the Heart Failure Cardiac Rehabilitation Room: A Randomized Controlled Trial

BACKGROUND

Although solid evidence has indicated that respiratory symptoms are common amongst patients with chronic heart failure (CHF), state-of-the-art cardiac rehabilitation (CR) programs do not typically include management strategies to address respiratory symptoms. This study investigated the effect of the addition of breathing exercises (BE) to the CR programs in CHF.

METHODS

In a two parallel-arm randomized controlled study (RCT), 40 middle-aged patients with CHF and respiratory symptoms were recruited and randomized into two equal groups (n = 20); group (A): standard CR with BE and group (B): standard CR alone. Primary outcomes were respiratory parameters and secondary outcomes included cardiovascular and cardiopulmonary outcomes. All the participants attended a program of aerobic exercise (three sessions/week, 60-75% MHR, 45-55 min) for 12 weeks, plus educational, nutritional, and psychological counseling. Group (A) patients attended the same program together with BE using inspiratory muscle training (IMT) and breathing calisthenics (BC) (six sessions/week, 15-25 min) for the same duration.

RESULTS

There was a significant improvement in the respiratory outcomes, and most of the cardiovascular and cardiopulmonary outcomes in both groups with a greater change percentage in group A (p < 0.05).

CONCLUSIONS

These results indicate that the addition of BE to the CR programs in CHF is effective and is a "patient-centered" approach.

Exercise Oscillatory Breathing in Heart Failure with reduced ejection fraction: clinical implication

AIM

I) to evaluate the impact of exertional oscillatory ventilation (EOV) in patients with heart failure (HF) with reduced left ventricular ejection fraction (HFrEF) during cardiopulmonary exercise testing (CPET) compared with patients without EOV (N-EOV); II) to identify the influence of EOV persistence (P-EOV) and EOV disappearance (D-EOV) during CPET on the outcomes of mortality and hospitalization in HFrEF patients; and III) to identify further predictors of mortality and hospitalization in patients with P-EOV.

METHODS AND RESULTS

315 stable HFrEF patients underwent CPET and were followed for 35 months. We identified 202 patients N-EOV and 113 patients with EOV. Patients with EOV presented more symptoms (NYHA III: 35% vs. N-EOV 20%, p < 0.05), worse cardiac function (LVEF: 28 ± 6 vs. N-EOV 39 ± 1, p < 0.05), higher minute ventilation/carbon dioxide production (V̇E/V̇CO2 slope: 41 ± 11 vs. N-EOV 37 ± 8, p < 0.05) and a higher rate of deaths (26% vs. N-EOV 6%, p < 0.05) and hospitalization (29% vs. N-EOV 9%, p < 0.05). P-EOV patients had more severe HFrEF (NYHA IV: 23% vs D-EOV: 9%, p < 0.05), had worse cardiac function (LVEF: 24 ± 5 vs. D-EOV: 34 ± 3, p < 0.05) and had lower peak oxygen consumption (V̇O2) (12.0 ± 3.0 vs D-EOV: 13.3 ± 3.0 mlO2.kg-1.min-1, p < 0.05). Among P-EOV, other independent predictors of mortality were V̇E/V̇CO2 slope ≥36 and V̇O2 peak ≤12 mlO2.kg-1.min-1; a V̇E/V̇CO2 slope≥34 was a significant predictor of hospitalization. Kaplan-Meier survival analysis showed that, HFrEF patients with P-EOV had a higher risk of mortality and higher risk of hospitalization (p < 0.05) than patients with D-EOV and N-EOV.

CONCLUSION

In HFrEF patients, EOV persistence during exercise had a strong prognostic role. In P-EOV patients V̇E/V̇CO2 ≥36 and V̇O2 peak ≤12 mlO2.kg-1.min-1, had a further additive negative prognostic role.

Prognostic value of key variables from cardiopulmonary exercise testing in patients with COPD: 42-month follow-up

AIM

To identify better predictors of early death in patients with chronic obstructive pulmonary disease (COPD) using potential predictors derived from key measures obtained from cardiopulmonary exercise testing (CPET).

METHODS

This is a prospective, cohort study with 42-month follow-up in 126 COPD patients. Every patient completed the clinical evaluation, followed by a pulmonary function test and CPET. CPET was performed on a cycle ergometer with electromagnetic braking and ventilatory expired analysis was measured breath-by-breath using a computer-based system. Peak oxygen consumption (V̇O_2, mlO_2. kg^-1_. min^-1), minute ventilation/carbon dioxide production and the, minute ventilation (V̇_E, L/min), and the V̇_E/carbon dioxide production (V̇_E/V̇CO₂) slope were obtained from CPET.

RESULTS

48 (38%) patients died during the 42-month follow-up. Kaplan Meier analysis revealed a V̇_E/V̇CO₂ slope ≥30, peak V̇_E ≤ 25.7L/min and peak V̇O₂ ≤ 13.8 mlO_2. kg^-1_. min^-1were strong predictors of mortality in COPD patients. Cox regression revealed that the V̇O₂ peak ≤13.8 mlO_2. kg^-1_. min^-1 (CI 95% 0.08-0.93), V̇_E/V̇CO₂ slope ≥30 (CI 95% 0.07-0.94), V̇_E peak ≤25.7 L/min (CI 95% 0.01-0.15), Sex (CI 95% 0.04-0.55) and Age (CI 95% 1.03-1.2) were the main predictors of mortality risk.

CONCLUSION

Diminished exercise capacity and peak ventilation as well as ventilatory inefficiency are independent prognostic markers. Similar to patients with heart failure, CPET may be a valuable clinical assessment in the COPD population.