Abstract
BACKGROUND: Evidence supports the clinical benefits of isolated inspiratory muscle training (IMT) in patients with chronic heart failure (CHF); however, the rationale of IMT in combination with exercise training in cardiac rehabilitation settings for CHF has yet to be confirmed. OBJECTIVE: This study aimed to assess the effect of the addition of IMT in combination with aerobic/resistance training (AT/RT) on maximal inspiratory pressure (PImax), peak oxygen consumption (VO(2peak)), selected hemodynamic variables, and health-related quality of life (HRQoL) compared to sham-IMT combined with AT/RT in patients with CHF. METHODS: Twenty-five male patients with CHF completed a 6-month cardiac rehabilitation program of either a sham-IMT/AT/RT program (control group, 51.84 ± 4.56 years old, n(1) = 13), or a real-IMT/AT/RT program (study group, 51.75 ± 4.73 years old, n(2) = 12). Inclusion criteria were ischemic heart failure, New York Heart Association (NYHA) class II-III, and reduced ejection fraction. Outcome measures were PImax, VO(2peak), resting heart rate (RHR), heart rate (HR) reserve, rate pressure product (RPP), left-ventricular ejection fraction, and Minnesota Living with Heart Failure Questionnaire (MLwHFQ). Absolute mean changes from baseline (Δ) in the outcome measures were statistically analyzed as independent outcomes. RESULTS: ΔPImax, ΔRHR, ΔHR reserve, and ΔMLwHFQ total score were significantly greater in the study group than in the control group (p < 0.05). In addition, ΔRPP showed an observed difference in favor of the study group with a tendency towards statistical significance (p = 0.07). CONCLUSIONS: IMT could be a successful complementary intervention to exercise-based cardiac rehabilitation programs comprising AT/RT, yielding greater improvements in PImax, RHR, HR reserve, and HRQoL in male patients with ischemic heart failure (NYHA class II-III).