Assessing Consequences of Intraaortic Balloon Counterpulsation Versus Left Ventricular Assist Devices at the Time of Heart Transplantation

Heart Transplantation

Heart transplantation (HTx) remains the last therapeutic resort for patients with advanced heart failure. The present work is a clinically focused review discussing current issues in heart transplantation. Several factors have been associated with the outcome of HTx, such as ABO and HLA compatibility, graft size, ischemic time, age, infections, and the cause of death, as well as imaging and laboratory tests. In 2018, UNOS changed the organ allocation policy for HTx. The aim of this change was to prioritize patients with a more severe clinical condition resulting in a reduction in mortality of people on the waiting list. Advanced heart failure and resistant angina are among the main indications of HTx, whereas active infection, peripheral vascular disease, malignancies, and increased body mass index (BMI) are important contraindications. The main complications of HTx include graft rejection, graft angiopathy, primary graft failure, infection, neoplasms, and retransplantation. Recent advances in the field of HTx include the first two porcine-to-human xenotransplantations, the inclusion of hepatitis C donors, donation after circulatory death, novel monitoring for acute cellular rejection and antibody-mediated rejection, and advances in donor heart preservation and transportation. Lastly, novel immunosuppression therapies such as daratumumab, belatacept, IL 6 directed therapy, and IgG endopeptidase have shown promising results.

Characteristic adverse events with intra-aortic balloon pumps: An analysis of the U.S. Food and Drug Administration MAUDE database from 2016 to 2021

INTRODUCTION

The United States Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) dataset represents a unique source for post-market surveillance data on adverse events (AE). An analysis of AE with percutaneous mechanical circulatory support (pMCS) devices has previously been reported specifically for microaxial flow pumps. The characteristic AE for the intra-aortic balloon pump (IABP) have not been similarly analyzed or reported.

MATERIAL AND METHODS

All events in the MAUDE dataset between January 1, 2016 and December 31, 2021 were reviewed involving the Linear, Mega and Sensation devices (Datascope/Getinge, Wayne New Jersey). Data was analyzed by two authors and categorized based on AE type, date, event type and device-related or patient-related AE.

RESULTS

A total of 2795 AE were reported over five years. Device malfunction (91.4 %) was the most frequent classification followed by death (5.6 %) and injury (3.0 %). Catheter deformation/fracture/leak accounted for 37.9 % of total AEs. The most common patient event categorization was asymptomatic (90.8 %). Vessel damage/hemorrhage occurred in 1.4 % of reports. Death occurred in 5.6 % of reports and was associated with cardiac arrest in 110 of 156 events. Thrombus formation was described in 1.1 % of AEs. Device optic AE were common and unique to Sensation catheters. Calibration errors were also more common with Sensation (4.6 % versus 1.3 %) compared to other models.

CONCLUSIONS

Publicly reported AE with IABPs are predominantly device malfunctions without clinical sequelae. Injury, vascular damage, bleeding and thrombosis AEs are not frequent amongst reported AEs. Emphasis should be placed on understanding mechanisms of device malfunction in order to improve both reliability and user experience.

A case of ultra-prolonged intra-aortic balloon pump support via sheathless femoral access

Background

An intra-aortic balloon pump (IABP) is a mechanical circulatory support platform with a relatively low complication rate. Axillary access is increasingly utilized to allow rehabilitation.

Case summary

We present a case of femoral IABP inserted into the femoral artery percutaneously via a sheathless technique that allowed the patient to ambulate and physically rehabilitate over 102 days until cardiac transplantation. The patient was able to progress with the protocolized rehabilitation programme to up to 3500 ft walking distance. The IABP was removed at the time of transplantation without any vascular complications.

Discussion

While axillary IABP offers an opportunity to rehabilitate, it has an unacceptably high complication rate, often resulting in vascular injury that adds morbidity to an acutely ill cohort. In this case, we found that sheathless femoral IABP access offered stability for a prolonged time while avoiding pain, bleeding, infection, and vascular injury. We hypothesize that this is due to less indwelling prosthetic material usage and also device flexibility, allowing conformation to the natural course of the femoral artery. We are encouraged by this case to use a sheathless access approach for patients expected to require prolonged IABP support.

Analysis of the revised heart allocation policy and the influence of increased mechanical circulatory support on survival

OBJECTIVES

In 2018, the new United Network for Organ Sharing heart allocation policy took effect. This study evaluated waitlist mortality, mechanical circulatory support utilization, and its influence on posttransplant survival.

METHODS

Two 12-month cohorts matched for time of year before and after the policy change were defined by inclusion criteria of first-time transplant recipients aged 18 years or older who were listed and underwent transplant during the same era. Student t test and Wilcoxon rank-sum test were used for mean and median differences, respectively. Categorical variables were compared using χ² or Fisher exact test. Kaplan-Meier curves were used to characterize survival, including time-to-event analysis with the log-rank test. Fine-Gray modeling was used to characterize waitlist mortality. Cox proportional-hazard models were used for multivariate analysis.

RESULTS

Waitlist mortality in the new era is significantly improved based on a competing-risks model (Gray test P = .0064). Unadjusted 180-day posttransplant mortality increased from 5.8% during the old era to 8.0% during the new (P = .0134). However, time-to-event analysis showed similar 180-day survival in both eras. After risk adjustment, the hazard ratio for posttransplant 180-day mortality during the new era was 1.18 (95% CI, 0.85-1.64; P = .333). The posttransplant 180-day mortality of the extracorporeal membrane oxygenation bridge-to-transplant subgroup improved from 28.6% in the old era to 8.4% in the new era (P = .0103; log-rank P = .0021). Patients with an intra-aortic balloon pump at the time of transplant had similar 180-day posttransplant mortality between eras (5.4% vs 7.0%; P = .4831).

CONCLUSIONS

The United Network for Organ Sharing policy change is associated with reduced waitlist mortality and similar risk adjusted posttransplant 180-day mortality. The new era is also associated with improved 180-day survival in patients undergoing bridge to transplant with extracorporeal membrane oxygenation.

Intra-Aortic Balloon Pumping in Acute Decompensated Heart Failure With Hypoperfusion: From Pathophysiology to Clinical Practice

Trials on intra-aortic balloon pump (IABP) use in cardiogenic shock related to acute myocardial infarction have shown disappointing results. The role of IABP in cardiogenic shock treatment remains unclear, and new (potentially more potent) mechanical circulatory supports with arguably larger device profile are emerging. A reappraisal of the physiological premises of intra-aortic counterpulsation may underpin the rationale to maintain IABP as a valuable therapeutic option for patients with acute decompensated heart failure and tissue hypoperfusion. Several pathophysiological features differ between myocardial infarction- and acute decompensated heart failure-related hypoperfusion, encompassing cardiogenic shock severity, filling status, systemic vascular resistances rise, and adaptation to chronic (if preexisting) left ventricular dysfunction. IABP combines a more substantial effect on left ventricular afterload with a modest increase in cardiac output and would therefore be most suitable in clinical scenarios characterized by a disproportionate increase in afterload without profound hemodynamic compromise. The acute decompensated heart failure syndrome is characterized by exquisite afterload-sensitivity of cardiac output and may be an ideal setting for counterpulsation. Several hemodynamic variables have been shown to predict response to IABP within this scenario, potentially guiding appropriate patient selection. Finally, acute decompensated heart failure with hypoperfusion may frequently represent an end stage in the heart failure history: IABP may provide sufficient hemodynamic support and prompt end-organ function recovery in view of more definitive heart replacement therapies while preserving ambulation when used with a transaxillary approach.

Changes in waitlist and posttransplant outcomes in patients with adult congenital heart disease after the new heart transplant allocation system

OBJECTIVE

In 2018, the United Network for Organ Sharing (UNOS) introduced new criteria for heart allocation. This study sought to assess the impact of this change on waitlist and posttransplant outcomes in adult congenital heart disease (ACHD) recipients.

METHODS

Between January 2010 and March 2020, we extracted first heart transplant ACHD patients listed from the UNOS database. We compared waitlist and post-transplant outcomes before and after the policy change.

RESULTS

A total of 1206 patients were listed, 951 under the old policy and 255 under the new policy. Prior to transplant, recipients under the new policy era were more likely to be treated with extracorporeal membrane oxygenation (P = .018), and have intra-aortic balloon pumps (P < .001), and less likely to have left ventricular assist devices (P = .027).Compared to patients waitlisted in the pre-policy change era, those waitlisted in the post policy change era were more likely to receive transplants (P = .001) with no significant difference in waiting list mortality (P = .267) or delisting (P = .915). There was no difference in 1-year survival post-transplant between the groups (P = .791).

CONCLUSION

The new policy altered the heart transplant cohort in the ACHD group, allowing them to receive transplants earlier with no changes in early outcomes after heart transplantation.

Intra-Aortic Balloon Pump Bridging to Heart Transplantation: Impact of the 2018 Allocation Change

BACKGROUND

This study evaluates the impact of the 2018 allocation policy change on outcomes of orthotopic heart transplantation (OHT) in patients bridged with intra-aortic balloon pumps (IABPs).

METHODS

Adult (≥18 years) patients undergoing OHT between 2013 and 2019 who were bridged with an IABP were stratified based on temporal relation to the policy change. Univariate analysis was used to compare baseline characteristics and postoperative outcomes. Multivariate Cox regression analysis was used to estimate risk-adjusted predictors of post-transplant mortality.

RESULTS

A total of 1342 (8.6%) OHT patients were bridged with an IABP during the study period. Rates of bridging with IABP to OHT increased significantly after the policy change (7.0% versus 24.9%, P<0.001). The mean recipient age was 54.1±12.1 years with 981 (73.1%) patients being male. Baseline characteristics were similar between the 2 groups whereas post-policy change patients spent fewer days on the waitlist (15 versus 35 days, P<0.001), had longer ischemic times (3.5 versus 3.0 hours, P<0.001), and received organs from a greater distance (301 versus 105 miles, P<0.001). By multivariable analysis, days on the waitlist (for every 30 days; odds ratio, 1.01 [95% CI, 1.00-1.02], P=0.031) and diabetes mellitus (odds ratio, 1.87 [95% CI, 1.16-3.02], P=0.011) emerged as significant predictors of post-transplant mortality. After the policy change, waitlisted patients requiring IABP support were more likely to survive to transplant (76.4 versus 89.8%, P<0.001).

CONCLUSIONS

IABP utilization has increased over 3-fold since the 2018 policy change with improved waitlist outcomes and comparable post-OHT survival. Thus, bridging patients to OHT with IABPs appears to be an effective strategy in the current era.

Noteworthy Literature Published in 2017 for Thoracic Transplantation Anesthesiologists

Thoracic organ transplantation constitutes a significant proportion of all transplant procedures. Thoracic solid organ transplantation continues to be a burgeoning field of research. This article presents a review of remarkable literature published in 2017 regarding perioperative issues pertinent to the thoracic transplant anesthesiologists.

Ambulatory Intra Aortic Balloon Pump in Advanced Heart Failure

Cardiac transplantation is the gold standard treatment for patients with advanced congestive heart failure that is refractory to maximal medical therapy. However, donor heart availability remains the major limiting factor, resulting in a large number of patients waiting long periods of time before transplantation. As a result, mechanical circulatory support devices have been increasingly used as a 'bridge' in order to sustain organ function and stabilise haemodynamics while patients remain on the transplant waiting list or undergo left ventricular assist device surgery. Intra aortic balloon pumps (IABP) are commonly used for temporary circulatory support in patients with advanced heart failure. IABP is traditionally placed percutaneously through the transfemoral artery approach. The major limitation with this approach is ambulatory restriction that can promote deconditioning, particularly in situations of prolonged circulatory support. A subclavian/axillary artery approach IABP insertion allows patients to be ambulatory during the pre-transplant period. In this review, we aim to summarise the physiology of IABP, the evidence for its use in advanced CHF and the efficacy and safety of subclavian artery IABP insertion.

The Axillary Intra-Aortic Balloon Pump as a Bridge to Recovery Allows Early Ambulation in Long-Term Use

We evaluated the feasibility, tolerability, and efficacy of a strategy for transaxillary artery intra-aortic balloon pump placement for extended mechanical circulatory support of patients with post-cardiotomy shock as a bridge to recovery. Patients requiring prolonged intra-aortic balloon pump support for postcardiotomy heart failure were identified. Intra-aortic balloon pump was tunneled through a 6-mm Dacron graft anastomosed to the right axillary artery. The intra-aortic balloon pump catheter is advanced under fluoroscopic guidance into the descending thoracic aorta. Three patients were transferred from outside facilities, requiring prolonged intra-aortic balloon pump support for postcardiotomy heart failure. Patients included a 54-year-old woman with occluded grafts and left ventricular thrombus after coronary artery bypass grafting, ejection fraction (EF) of 23.4% on dobutamine infusion, intra-aortic balloon pump support for 39 days, max daily ambulated distance of 1250 feet, and discharged home on day 51 on milrinone infusion; a 63-year-old man with kinked left internal mammary artery to left anterior descending artery graft (surgically repaired), multiple failed extubations requiring tracheostomy, EF of 15% on epinephrine and milrinone, intra-aortic balloon pump support for 43 days, max daily ambulated distance of 400 feet, and discharged home on day 54; and a 66-year-old man after redo coronary artery bypass grafting + carotid endarterectomy, with failure to wean off cardiopulmonary bypass requiring veno-arterial extracorporeal membrane oxygenator, EF of 20% on epinephrine and norepinephrine, intra-aortic balloon pump support for 41 days, max daily ambulated distance of 2800 feet, and discharged home on day 91. There were no infection, thromboembolic, cerebrovascular, bleeding, or intra-aortic balloon pump malpositioning/migration complications. We found that transaxillary artery intra-aortic balloon pump is well tolerated by patients and allows early ambulation and aggressive physical therapy in patients needing extended support. Duration of intra-aortic balloon pump support was up to 43 days with no complications.