Optimal left ventricular (LV) mechanical unloading in patients with advanced heart failure with LV assist devices (LVADs) was more likely to be maintained when pump speed was progressively up-titrated during outpatient follow-up, according to study results published in the Journal of the American Society of Echocardiography.
Reverse remodeling occurs in patients implanted with LVADs, through LV mechanical unloading. A 15% reduction in LV end-diastolic diameter (LVEDD) compared with pre-LVAD measurements is recommended, but the amount of unloading varies significantly from patient to patient.
In this single-center retrospective chart review, the data of 75 patients (mean age, 48±14 years; 88% men) with advanced heart failure (75% with ischemic dilated cardiomyopathy) who received LVADs between January 2010 and July 2017 were examined. Echocardiographic data were analyzed at 5 time points: pre-implantation, within 2 weeks post-LVAD implantation, and at 1, 3, and 6 months after implantation.
The study’s primary outcome was the LVEDD percentage change from pre-LVAD to 6 months post-LVAD (ΔLVEDD). A ≥15% reduction during this period was considered optimal LV unloading. Structural, clinical, and hemodynamic findings were examined in patients with vs without optimal unloading (n=30 and n=45, respectively) to assess the usefulness of this criterion as a management target.
At 6 months, patients who had vs did not have optimal unloading had: lower pulmonary capillary wedge pressure (9±4 vs 16±7 mm Hg, respectively; P =.02), lower moderate/severe mitral regurgitation rates (10% vs 33%, respectively; P =.02), higher fractional shortening (15%±7% vs 10%±7%, respectively; P =.007), higher ΔLVEDD (23%±7% vs 6%±5%, respectively; P <.001), and lower right ventricular (43% vs 73%, respectively; P =.008).
The percentage increase in pump speed (ie, change in revolutions per minute [ΔRPM]) from hospital discharge to 6 months was higher in the optimal vs suboptimal unloading group (4.4%±3.7% vs 0.1%±2.6%, respectively; P <.001). The tricuspid annular systolic velocity (P =.008) and ΔRPM (P < .001) at 6 months, as well as the pre-LVAD LVEDD (P = .003) were found to be independently associated with ΔLVEDD at 6 months.
Rates of major complications, LVAD mortality, and survival to heart transplant did not differ significantly between the optimal and suboptimal unloading groups.
Study limitations include its retrospective design, small sample size, cohort and device heterogeneity, exclusion of patients with nondilated cardiomyopathy, and use of LV dimensional vs volumetric change for quantification of unloading.
“These data support continuing to optimize pump speeds in outpatients with LVADs rather than relying on pump settings at discharge,” noted the authors.
William J, Mak V, Leet A, Kaye DM, Nanayakkara S. Optimal mechanical unloading in left ventricular assist device recipients relates to progressive up-titration in pump speed. J Am Soc Echocardiogr. March 2020:1-11. doi:10.1016/j.echo.2020.01.002