Abstract Body (Do not enter title and authors here): BACKGROUND: Adjusting left ventricular assist devices (LVAD) pump speed during exercise may enhance hemodynamics and improve functional capacity in patients with advanced heart failure. While intuitively promising, it remains unclear whether speed modulation during exercise offers meaningful advantages over fixed-speed settings. RESEARCH QUESTION: Does exercise-driven dynamic pump speed modulation improve physical capacity outcomes compared to fixed-speed settings in patients with LVADs ? METHODS: A systematic search of PubMed, Embase, and the Cochrane Library was performed from inception until March 2025, following PRISMA guidelines evaluating studies involving effects of dynamic versus fixed LVAD pump speed during exercise. Desired outcomes assessing peak VO2, pump speed, cardiac output and ventilatory efficiency were collected. Pooled effect sizes were calculated using random-effects models. For continuous outcomes, mean or standardized mean differences with 95% confidence intervals were used. All statistical analyses were performed using Review Manager.
RESULTS: We collected 8 studies involving a total 129 patients. Of them, 7 studies were of cross-over design leading to 121 patients submitted to adjusted speed protocol and 118 to the fixed-speed setting. Compared to fixed-speed settings, adjusted pump speed significantly improved peak oxygen consumption (MD 1.34 mL/kg/min; 95% CI 0.51 to 2.17; p = 0.002) and increased pump flow at peak exercise (MD 0.92 L/min; 95% CI 0.52 to 1.32; p < 0.00001). It was also associated with a significantly higher achieved pump speed during exercise (MD 1101.48 rpm; 95% CI 532.25 to 1670.70; p < 0.0001). No significant differences were observed in cardiac output at peak exercise (MD –0.31 L/min; 95% CI –1.17 to 0.56; p = 0.49) or in ventilatory efficiency slope (MD –0.76; 95% CI –2.86 to 1.34; p = 0.48).
CONCLUSION: Dynamic pump speed adjustment during exercise is associated with improved peak oxygen consumption and enhanced pump flow compared to fixed-speed settings in LVAD patients, suggesting better exercise performance.