Exercise oscillatory breathing in heart failure with reduced ejection fraction: clinical implication.

Area of Science:

• Cardiology
• Pulmonary Medicine
• Exercise Physiology

Background:

• Heart failure with reduced left ventricular ejection fraction (HFrEF) is a complex condition impacting exercise capacity and prognosis.
• Exercise oscillatory ventilation (EOV) is an abnormal breathing pattern observed during cardiopulmonary exercise testing (CPET).
• The prognostic significance of EOV and its persistence in HFrEF patients requires further elucidation.

Purpose of the Study:

• To evaluate the impact of EOV during CPET in HFrEF patients.
• To determine the influence of EOV persistence (P-EOV) versus disappearance (D-EOV) on mortality and hospitalization.
• To identify additional predictors of adverse outcomes in HFrEF patients with persistent EOV.

Main Methods:

• 315 stable HFrEF patients underwent CPET and were followed for 35 months.
• Patients were categorized into those with EOV (n=113) and no EOV (N-EOV, n=202).
• Subgroup analysis was performed for patients with persistent EOV (P-EOV) versus disappeared EOV (D-EOV).

Main Results:

• EOV patients exhibited more severe symptoms, worse cardiac function (LVEF), higher minute ventilation/carbon dioxide production (V̇E/V̇CO2 slope), and increased mortality and hospitalization rates compared to N-EOV.
• P-EOV patients had more severe HFrEF, poorer cardiac function, and lower peak oxygen consumption (V̇O2) than D-EOV patients.
• In P-EOV patients, V̇E/V̇CO2 slope ≥36 and V̇O2 peak ≤12 mL·kg⁻¹·min⁻¹ were independent predictors of mortality, while V̇E/V̇CO2 slope ≥34 predicted hospitalization.

Conclusions:

• Persistent EOV during exercise is a significant negative prognostic indicator in HFrEF patients.
• Specific CPET parameters (V̇E/V̇CO2 slope and V̇O2 peak) provide further prognostic information in P-EOV patients.
• These findings highlight the importance of assessing EOV during CPET for risk stratification in HFrEF.