Temporal behavior of exercise oscillatory ventilation and respiratory muscle performance in patients with heart failure

Background: Exercise oscillatory ventilation (EOV) is a negative prognostic marker in patients with heart failure (HF). EOV can either disappear (D-EOV) or persist (P-EOV) during exercise, with each showing different clinical implications. The relationship between respiratory muscle weakness and EOV persistence is not well understood, and its impact on exercise performance and muscle function in HF patients needs further exploration. Methods: This study included 98 clinically stable HF patients with reduced left ventricular ejection fraction (LVEF), all undergoing cardiopulmonary exercise testing (CPET) and measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP). EOV was classified as D-EOV or P-EOV, and the temporal behavior of EOV was analyzed in relation to inspiratory muscle weakness (IMW), using standard ERS criteria. Results: Patients with P-EOV were older, with lower BMI, showed worse exercise performance, with lower peak workload (47 [38;59] vs. 67 [52;94] watts) and pVO2 (10.8 [9.3;12.7] vs. 13.4 [12.1;16.0] mL/kg/min). Respiratory muscle strength was weaker in P-EOV patients (MIP: 73.3 ± 25.6 vs. 93.4 ± 26.6 cmH2O; MEP: 102.9 ± 40.9 vs. 131.8 ± 40.8 cmH2O). A higher proportion of P-EOV patients had IMW (p < 0.05). P-EOV patients with IMW had worse exercise capacity, lower BMI and lower exercise performance (peak workload = 41.5 [36;52] vs. 63 [46;86] watts) than those with D-EOV and IMW. Conclusions: EOV persistence is associated with worse exercise performance, respiratory muscle weakness, and potentially sarcopenia in HF patients.