Impact of Partial- to Full-Support Escalation With Microaxial Flow Pumps Prior to Durable Left Ventricular Assist Device Implantation

Objectives: Microaxial flow pumps (mAFP) effectively bridge patients with cardiogenic shock to durable left ventricular assist device (dLVAD) implantation. The partial-support mAFPs provide only up to 3.5 L/min, which might be insufficient for an effective circulatory support and preconditioning for a dLVAD implantation. Alternatively, patients with refractory shock on partial support may benefit from an escalation to a full-support mAFP. Methods: A retrospective analysis of 130 patients was performed across 17 European cardiac centres who underwent dLVAD implantation following mAFP with or without venoarterial extracorporeal life support (VA-ECLS) between February 2015 and August 2022. Ninety-two patients (70.8%) were bridged on partial-support mAFP, while 38 patients (29.2%) underwent an escalation to full-support mAFP. Results: Median support duration was significantly longer in the escalation group (7 days [4, 11] vs 12 days [9, 21], P < .001). Patients in the escalation group were more likely to be weaned from VA-ECLS before dLVAD implantation, 10 (71.4%) vs 6 (11.3%), P < .001. Thirty-day survival was similar between the escalation and no-escalation groups, 89.5% vs 84.8% (IPTW-weighted OR, 1.00 [95% CI, 0.46-2.22], P = .992). Estimated 1-year survival was higher in the escalation group: 84.0% [95% CI, 73.0-96.6] vs 63.7% [95% CI, 54.3-74.6], HR 0.41 [95% CI, 0.17-0.99], P = .048. Patients with a combination of partial-support mAFP and VA-ECLS had a higher mortality risk than all other patients, HR 2.06 [95% CI, 1.16-3.36], P = .013. Conclusions: In patients with partial-support mAFP and concomitant VA-ECLS, an escalation to a full-support mAFP may translate to improved survival and should be considered to facilitate VA-ECLS weaning.