The Need for Speed: A “Maverick” Approach Towards Optimizing Lvad Pump Speed by Focusing on Pressure-flow Relationships

Abstract

Introduction Optimal LVAD speed should be adjusted to adequately unload the left ventricle. Historic parameters such as septal position, degree of mitral regurgitation, and Aortic Valve opening have been used as surrogates for optimal pump speed in previous generation pumps. Our program has used hemodynamic ramp studies to optimize Pressure-Flow relationships and minimize wedge pressure independent of echo parameters. We share our experience with patients maintained at higher speeds than reported in the literature. Objective Examine the effects of higher pump speed in patients with Heartmate 3 LVADs. Methods A retrospective chart review of all the patients receiving LVADs at single center was performed. All patients who had Heartmate 3 implant between October 2018 and January 2020 were included (n= 38) Patients were divided into High-Speed group consisting of patients with speeds > 5600 rpm (n=20) and Low-Speed group, Results (Table 1): The absolute number of readmissions at 3-month visits was lower in the high-speed group (3 vs 12), but it was statistically insignificant (p 0.238). Similarly, the high-speed group had improved KCCQ scores (16 vs 12, p=0.55) that was not statistically significant. The high-speed group had a larger number of patients with elevated creatinine at the time of implant, most of these patients improved in 3 months (8 out of 10) as compared to the low-speed group which saw an upward trend in creatinine post-implant. Conclusion While little has been published on optimal pump speed in the Heartmate 3, Pressure-Flow curves suggest a clear advantage of running continuous flow pumps at higher RPMs. Unfortunately, our sample size is retrospective and underpowered, however, there appears to be a trend towards better outcomes in a small population maintained at higher pump speeds. A larger, and ideally prospective clinical trial to find optimal pump speeds for patients may provide insight into this issue and improve outcomes post-implant.