Non-Invasive Ventilatory Support as a Tool to Improve Exercise Tolerance in Patients With Heart Failure: A Systematic Review With Meta-Analysis

Background and Purpose: Heart failure (HF) is a complex syndrome that impacts persons' daily activities and adherence to exercise programs. Non-Invasive ventilation (NIV) reduces respiratory load and improves cardiac function, potentially serving as an important adjunct in its treatment. These effects can be enhanced with a cardiac rehabilitation program, improving dyspnea and functionality. This study aimed to evaluate the effects of NIV during exercise on functional performance outcomes, dyspnea, QL, hemodynamics, and respiratory function. Methods: A systematic review followed by meta-analysis was conducted. Searches were performed in PubMed, CENTRAL, Embase, LILACS, SciELO, and CINAHL. Eligibility criteria: Randomized clinical trials of patients over 18 years of age with HF, compared to a control group, were included with the objective of improving exercise tolerance. The studies were categorized as short-term effects of NIV and those implementing an exercise program. Results: Seven studies were included in the qualitative review and five in the meta-analysis. Only two studies presented a low risk of bias. The analyzed outcomes were the 6-min walk test (6MWT), dyspnea, SpO2, heart rate (HR), systolic, and diastolic arterial pressure (SAP and DAP, respectively), maximal inspiratory and expiratory muscle strength (MIP and MEP, respectively), forced expiratory volume in one second (FEV1), and quality of life (QL). DiscussionThere was a significant difference in favor of the NIV group compared to the control group in both modalities in relation to the 6MWT, with a mean difference (MD) 41.72 (CI 95% 2.15, 81.29) meters in the exercise program and MD 68.61 (CI 95% 5.69, 131.54) meters in short-term effect studies. There were also favorable results in the outcomes of dyspnea and FEV1 in the NIV group (p < 0.01). There were no statistically significant differences in the outcomes peripheral oxygen saturation (p = 0.11), systolic (p = 0.76) and diastolic blood pressure (p = 0.93), heart rate (p = 0.19), MIP (p = 0.49), MEP (p = 0.22) and QL (p = 0.13).