Baseline ECHO a Suitable Screening Tool for LV Recovery during CF LVAD Support

Abstract

Purpose A lack of standardized protocols looking for cardiac recovery during CF LVAD support is partially responsible for low rates of device explant. LVAD wean assessments are time consuming and therefore often not performed. We sought to determine whether a baseline (full-support) echo could serve as a screening assessment to identify those individuals with explant potential who should undergo wean assessment. Methods A retrospective review of all LVAD weaning studies performed at Montefiore between 2007 and 2018 was conducted. LVAD weaning studies were performed with HMII at 6000 rpms and HVAD at 1800rpms which are the generally accepted “net-zero” flows for each device. For individuals who had multiple weaning assessments, only the most recent was analyzed. Only those studies with adequate windows as defined by clear endocardial definition in both apical 4 and 2 chamber views were included. LV diameters, volumes by Simpson's biplane method, LVEF and RV fractional area changes (FAC) were measured at the baseline LVAD speed and at weaned speed after 15minutes. Results Of the 57 patients who had weaning studies, 41 met the inclusion criteria with a mean age of 46 yrs, 41.5% ischemic etiology, 24% female, and a median duration of 222 days of LVAD support. During wean assessments, there was an increase in all measures of LV size: LVIDd - 5.83cms to 6.15cm, LVEDV - 191mL to 207mL (p=0.0001) and LVESV - 141mL to 148mL. There was a corresponding modest increase in LVEF from 31 to 34% (p=0.07). Fourteen (34%) had a LVEF >40% on baseline echo; 5 of these went on to normal LVEF (>50%) on wean study. Conversely, no patient with a LVEF Conclusion During LVAD wean there was evidence of LV re-loading as shown by an increase in LV volumes and a modest increase in LVEF. An LVEF >40% on baseline echo identified all patients with a normal LVEF during wean assessment and therefore may serve as an appropriate screening tool.