Less-invasive ventricular assist device implantation: A multicenter study

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

A novel intrapericardial pulsatile device for individualized, biventricular circulatory support without direct blood contact

OBJECTIVE

Due to severely limited donor heart availability, durable mechanical circulatory support remains the only treatment option for many patients with end-stage heart failure. However, treatment complexity persists due to its univentricular support modality and continuous contact with blood. We investigated the function and safety of reBEAT (AdjuCor GmbH), a novel, minimal invasive mechanical circulatory support device that completely avoids blood contact and provides pulsatile, biventricular support.

METHODS

For each animal tested, an accurately sized cardiac implant was manufactured from computed tomography scan analyses. The implant consists of a cardiac sleeve with three inflatable cushions, 6 epicardial electrodes and driveline connecting to an electro-pneumatic, extracorporeal portable driver. Continuous epicardial electrocardiogram signal analysis allows for systolic and diastolic synchronization of biventricular mechanical support. In 7 pigs (weight, 50-80 kg), data were analyzed acutely (under beta-blockade, n = 5) and in a 30-day long-term survival model (n = 2). Acquisition of intracardiac pressures and aortic and pulmonary flow data were used to determine left ventricle and right ventricle stroke work and stroke volume, respectively.

RESULTS

Each implant was successfully positioned around the ventricles. Automatic algorithm electrocardiogram signal annotations resulted in precise, real-time mechanical support synchronization with each cardiac cycle. Consequently, progressive improvements in cardiac hemodynamic parameters in acute animals were achieved. Long-term survival demonstrated safe device integration, and clear and stable electrocardiogram signal detection over time.

CONCLUSIONS

The present study demonstrates biventricular cardiac support with reBEAT. Various demonstrated features are essential for realistic translation into the clinical setting, including safe implantation, anatomical fit, safe device-tissue integration, and real-time electrocardiogram synchronized mechanical support, result in effective device function and long-term safety.

Stroke and pump thrombosis following left ventricular assist device implantation: The impact of the implantation technique

Objectives

Several studies have shown the potential advantage of less-invasive surgery (LIS) for left ventricular assist device (LVAD) implantation. This study aims to determine the impact of LIS on stroke and pump thrombosis events after LVAD implantation.

Methods

Between January 2015 and March 2021, 335 consecutive patients underwent LVAD implantation using either conventional sternotomy (CS) or the LIS technique. Patient characteristics was prospectively collected. All patients were followed up until October 2021. Logistic multivariate regression and propensity-matched analyses were performed to account for confounding factors.

Results

A total of 242 patients (F = 32; 13.0%) underwent LVAD implantation with CS and 93 patients (F = 8; 8.6%) with the LIS approach. Propensity matching generated two groups, including 98 patients in the CS group and 67 in the LIS group. Intensive care unit stay for the LIS group patients was significantly shorter than that for the CS group patients [2 (IQR: 2-5) days vs. 4 (IQR: 2-12) days, p < 0.01]. There were no significant differences in the incidence of stroke events (14% in CS vs. 16% in the LIS group; p = 0.6) or in pump thrombosis (6.1% in CS vs. 7.5% in the LIS group; p = 0.8) between the groups. The hospital mortality rate in the matched cohort was significantly lower in the LIS group (7.5% vs. 19%; p = 0.03). However, the 1-year mortality rate showed no significant difference between both groups (24.5% in CS and 17.9% in LIS; p = 0.35).

Conclusions

The LIS approach for LVAD implantation is a safe procedure with potential advantage in the early postoperative period. However, the LIS approach remains comparable to the sternotomy approach in terms of postoperative stroke, pump thrombosis, and outcome.

Long-term Outcomes in Ventricular Assist Device Outflow Cannula Anastomosis to the Descending Aorta

BACKGROUND

Left ventricular assist device (LVAD) implantation via thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative implantation technique that uses a single incision and avoids anterior mediastinal planes. We evaluated long-term survival and hospital readmissions following LVAD implantation via thoracotomy with outflow cannula anastomosis to the descending aorta.

METHODS

Adult patients implanted with a continuous flow centrifugal LVAD at an academic center were retrospectively analyzed. Patients were assigned to one of the two cohorts based on the anastomosis site of the LVAD outflow cannula: ascending aorta cohort (Asc-Ao) and descending aorta cohort (Desc-Ao). Primary and secondary outcomes were survival and hospital readmissions during device support. Readmission analysis included patients with ≥30-day survival following discharge. Multivariable analysis and propensity score matching were performed.

RESULTS

Survival analysis included 330 patients (Asc-Ao: 272, Desc-Ao: 58). Readmission analysis included 277 patients (Asc-Ao: 231, Desc-Ao: 46) and a total of 1028 readmissions during 654 patient-years of follow-up were analyzed. There was no significant difference in in-hospital, 6-month, 1-year, 3-year and 5-year mortality between the two cohorts. Readmission-free survival, 30-day readmission, number of admissions per year and hospital length of stay per year were not significantly different between the 2 cohorts following adjustment for patient characteristics.

CONCLUSIONS

This study found no difference in long-term survival or hospital readmissions between LVAD implantation via thoracotomy with outflow cannula anastomosis to the descending aorta and standard implantation.

Exercise capacity following ventricular assist device implantation via thoracotomy with outflow cannula anastomosis to the descending aorta

Left ventricular assist device (LVAD) implantation via left lateral thoracotomy with outflow cannula anastomosis to the descending aorta is an alternative technique that avoids anterior mediastinal planes and requires a single incision. This study compares changes in exercise capacity following LVAD implantation with outflow cannula anastomosis to the descending aorta versus ascending aorta. Adult patients who received a continuous flow centrifugal LVAD implantation and completed both pre- and postimplantation cardiopulmonary exercise tests (CPETs) and or 6-minute walk tests (6MWT) were included. Change in CPET parameters (maximum oxygen intake: vO₂ max, oxygen uptake efficiency ratio: OUES, ventilatory efficiency ratio: vE/vCO₂ Slope) and 6MWT distance were compared between ascending and descending aorta anastomosis groups. Ascending and descending aorta anastomosis cohorts included 59 and 14 patients, respectively. Pre- and postimplantation CPETs were performed 63 ± 12 days before and 216 ± 17 days following implantation. The improvement in CPET parameters (vO₂ max, OUES, vE/vCO₂ Slope) or 6MWT distance was not significantly different between the ascending and descending aorta anastomosis groups. This study found no significant difference in the improvement of CPET parameters or 6MWT distance between LVAD implantation via thoracotomy with outflow cannula anastomosis to descending aorta and standard implantation via sternotomy with outflow cannula anastomosis to ascending aorta.