Longitudinal analysis of pump parameters over long-term support with the HeartMate 3 left ventricular assist device

Abstract

Aims Recurrence of heart failure emerged as the main cause of long-term mortality in patients implanted with the HeartMate 3 (HM3) left ventricular assist device (LVAD). We aimed at deriving a possible mechanistic rationale of clinical outcomes and analyzed longitudinal changes in pump parameters over prolonged HM3 support to investigate long-term effects of pump settings on left ventricular mechanics. Methods Data on pump parameters (i.e. pump speed, estimated flow, and pulsatility index) were prospectively recorded in consecutive HM3 patients following postoperative rehabilitation (baseline) and then at 6, 12, 24, 36, 48, and 60 months of support. Results Data of 43 consecutive patients were analyzed. Pump parameters were set according to regular patients’ follow-up, including clinical and echocardiographic assessment. We recorded a significant progressive increase in pump speed over the course of support: from 5200 (5050–5300) rpm at baseline to 5400 (5300–5600) rpm at 60 months of support (P = 0.0007). Consistently with the increase in pump speed, a significant increase in pump flow (P = 0.007) and a decrease in pulsatility index (P = 0.005) were also recorded. Conclusion Our results reveal unique features of the HM3 on left ventricular activity. The need for progressive increase in pump support suggests indeed a lack of recovery and worsening of left ventricular function, which emerge as a possible mechanistic rationale of heart failure related mortality in HM3 patients. New algorithms to optimize pump settings should be envisioned to further improve LVAD-LV interaction and, ultimately, clinical outcomes in the HM3 population. Clinical Trial Registration https://clinicaltrials.gov/ct2/show/NCT03255928 ClinicalTrials.gov Identifier NCT03255928