Ventricular assist devices as bridge to heart transplantation: minimally invasive approach with axial pumps vs sternotomy approach with centrifugal pumps: short term results
Authors: Ramos Martinez R , Plaza Martin M , Tobar Ruiz J , Garcia Cabello A , Cabezon Villalba G , Martin Paniagua S , Carnicero Martinez D , Hernandez Luis C , Javier Lopez Diaz J , De La Fuente Galan L , Amat Santos I J , Pastor Baez G , Stepanenko A , Bustamante Munguira J , San Roman Calvar J A 
Published: October 2024

Abstract

Introduction
Microaxial flow ventricular assist devices (VADs) with hybrid approach could provide an advantage over centrifugal flow VADs with surgical implantation via median sternotomy as bridge to heart transplantation.

Purpose
We aimed to compare short-term results in intensive cardiac care unit between both groups.

Methods
Single-center retrospective registry comparing patients supported with microaxial flow VADs with hybrid approach (Impella 5.0 or 5.5) and surgical centrifugal flow VADs (biventricular or left univentricular CentriMag) as bridge to heart transplantation.

Results
Including 12 patients (January 2020-March 2022), 7 patients in hybrid approach group (2 patients with Impella 5.0-16,7% and 5 patients with Impella 5.5-41,7%) and 5 pacientes in sternotomy approach group (33.3% biventricular support and 8.3% left ventricular support). In first 48 hours after VAD implantation, worsening of renal function was greater in sternotomy approach group (Cr 2.23±0.88, 1.07±0.58;p=0.021) and there was a trend toward lower hemoglobin values (7.72±0.19, 8.9±1.35;p =0.059), with no differences in other analyzed variables (Table). A trend toward earlier respiratory weaning was observed in hybrid approach group (median 12 vs 48 hours,p=0.067). Sternotomy approach group required more frequent use of continuous renal replacement therapy (60% vs 0%,p=0.045). There were statistically non-significant differences in need for blood products or surgical reinterventions, although percentage of red blood cells transfused in first 48 hours after VAD implantation were lower in hybrid approach group than sternotomy approach group (median 4 (1.5-8) versus 8(2.5-13.5) in sternotomy approach group, p=0.309). The most common complication in sternotomy approach group was tamponade (80%- 4 patients versus 0 patients in hybrid approach) and in hybrid approach group access-related infections (28.57%, 2 patients). Ten patients received a transplant, one died for non-cardiovascular cause, and another underwent the implantation of long term VAD as bridge to transplantation. There were no differences in time from assistance implantation to heart transplantation. The most common complication after heart transplantation was primary graft failure in both groups (40%,2 patients) with no differences in mortality.

Conclusions
Microxial flow VADs with hybrid approach provide adequate support, with less need for continuous renal replacement therapy and shorter duration of mechanical ventilation after VAD implantation to admission in intensive cardiac care unit, a trend towards lower rates of reintervention due to bleeding was observed. The advantages of minimally invasive approach could increase its use as bridge to heart transplantation compared to VADs with sternotomy approach although small sample size may negatively influence the failure to reach statistical significance, and more studies are necessary to validate our preliminary experience.Variables analyzed 48 hours of admission