Abstract 9754: Low Diastolic Arterial Pressure During Pre-Explant Off-Pump Trials can Induce Misleading Overestimation of Left Ventricular Function with Potential Risk for Early Recurrence of Heart Failure after Left Ventricular Assist Device Removal
Background A major goal after left ventricular assist device (LVAD) implantation is the detection of myocardial recovery which allows LVAD removal. After normalization of LV size, the pre-explant off-pump LVEF is paramount for selection of patients with the potential to remain stable after LVAD removal. However, patients with similar off-pump LVEF but different systemic arterial pressure during off-pump trials often show differences in post-explant cardiac stability. We assessed the importance of diastolic pressure for weaning decisions.
Methods Among the 82 patients weaned from LVADs since 1995, we selected for evaluation a more homogenous patient cohort which included only those with idiopathic dilated cardiomyopathy before LVAD insertion and pre-explant off-pump LVEF ≥ 45%. We analyzed the relationship between post-weaning stability and pre-explant LV size, geometry and function (end-diastolic diameter, relative wall thickness and short/long axis ratio, systolic wall motion velocity and LVEF), considering also the arterial pressure during off-pump trials.
Results Pre-explant LVEF in the evaluated patients was 49 ±3.9%. There were no significant differences in pre-explant LVEF between patients with and without heart failure (HF) recurrence during the first 5 post-weaning years (48.5 ±2% vs. 49.2 ±4.3%), but patients with HF recurrence had lower diastolic arterial pressure during the final pre-explant off-pump trial in comparison with post-weaning stable patients. (47.9 ±3.6mmHg vs. 66.9 ±7.8mmHg, p<0.001). Pre-explant off-pump LVEF < 55% with low diastolic arterial pressure of ≤ 50mmHg showed 87.5% predictive value for post-weaning HF recurrence. After maximum unloading promoted cardiac improvement, patients with off-pump arterial diastolic pressure ≤ 50mmHg showed higher pre-explant alterations for all off-pump parameters related to LV size, geometry and function than patients who had off-pump arterial diastolic pressure > 50mmHg (p < 0.05).
Conclusion Reduced LV afterload in patients with low off-pump diastolic arterial pressure can induce misleading overestimation of LV function. In patients with pre-explant LVEF ≥ 45%, off-pump diastolic arterial pressure ≤ 50mmHg is a relevant risk factor for post-weaning HF recurrence.
- © 2012 by American Heart Association, Inc.