Changes in Left Ventricular Ejection Fraction Following Implantation of Left Ventricular Assist Device as Destination Therapy

Abstract

Purpose Recovery of left ventricular (LV) function has been reported following prolonged myocardial unloading with left ventricular assist device (LVAD) therapy. However, recovery appears to be limited to younger patients presenting acutely with non-ischemic heart failure (HF), and it is unclear how often LV recovery occurs after destination LVAD. Methods and Materials Patients undergoing destination LVAD at the Mayo Clinic in Minnesota from April 2007 to February 2012 with at least 6 months of follow-up were included. Ejection fraction (EF) was obtained from transthoracic echocardiographic studies pre-LVAD and at 6 and 12 months post-LVAD. Use of beta blockers, ACE inhibitors, angiotensin-receptor blockers, and aldosterone antagonists at hospital dismissal were recorded. Patients were censored at death or last follow-up. Results Among 69 patients (mean age 64 years, 16% female, 59% ischemic HF, 97% continuous-flow LVAD), the mean EF was 18% pre-LVAD, 23% 6 months post-LVAD, and 22% 12 months post-LVAD. At 6 and 12 months post-LVAD, the EF increased by a mean of 5% and 4% compared with baseline, respectively (paired t-test p=0.001). By one year post-LVAD, 13 (22%) patients had an increase in EF of ≥10%, with greater improvements in those with lower pre-LVAD EF. The change in EF was similar in patients with ischemic (mean EF increase 3%) vs. nonischemic HF (mean EF increase 7%, p=0.13). Use of HF medications had no impact on the change in EF. There were only 2 patients who had an improvement in EF to ≥50% by 1 year. There was no association between change in EF at 6 months and subsequent mortality. Conclusions In our experience, EF only improved slightly after destination LVAD, and rarely reached a normal range. This suggests that mechanical unloading alone is not the main mechanism for LV recovery in end-stage HF. It is possible that use of LVADs may allow myocardial recovery in the setting of novel pharmacologic or cell based interventions.