Bridge to Transplantation: Current Outcomes

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.

Living with a left ventricular assist device: Capturing recipients experiences using group concept mapping software

Background

Left ventricular assist device (LVAD) implantation significantly impacts on a recipient’s symptoms and quality of life. Capturing their experiences and post implant journey is an important part of clinical practice, research and device design evolution. Patient reported outcome measures (PROMs) are a useful tool for capturing that experience. However, patient reported outcome measures need to reflect recipients’ experiences. Discussions with a patient partner group found that none of the frequently used cardiology PROMs captured their unique experiences.

Aims

To capture the experiences and important issues for LVAD recipients. Develop a conceptual map of domains and items that should be reflected in patient reported outcomes.

Methods

Group concept mapping (GCM) web-based software was used to remotely capture and structure recipients’ experiences across a wide geographical area. GCM is a semi-quantitative mixed method consisting of 3 stages: item generation, item sorting and rating (importance, relevance and frequency). Patient partners were involved in all aspects of the study design and development.

Results

18 LVAD recipients consented to take part. 101 statements were generated and multi-dimensional scaling, and hierarchical cluster analysis identified 9 clusters. Cluster themes included: Activities, Partner/family support, Travel, Mental wellbeing, Equipment and clothing, Physical and cognitive limitations, LVAD Restrictions, LVAD Challenges and positive impact of the LVAD (LVAD Positives). LVAD Positives were scored highest across all the rating variables, e.g., frequency (2.85), relevance (2.44) and importance (2.21). Other domains rated high for importance included physical and cognitive limitations (2.19), LVAD restrictions (2.11), Partner/family support (2.02), and Equipment and clothing (2.01).

Conclusion

Online GCM software facilitated the inclusion of geographically dispersed recipients and provided useful insights into the experiences of LVAD recipients. The conceptual framework identifies important domains and items that should be prioritised and included in patient reported outcomes in future research, LVAD design evolution, and clinical practice.

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

The proportion of heart transplant recipients bridged with durable, intracorporeal left ventricular assist devices (dLVADs) has dramatically increased; however, concern exists regarding obligate repeat sternotomy, increased bleeding risk because of anticoagulation and acquired von Willebrand disease, and increased rates of allosensitization. Whether dLVAD patients have impaired posttransplant outcomes compared with equivalent patients with less invasive intraaortic balloon pump counterpulsation (IABP) at the time of transplant is unknown. Therefore, we analyzed adult, first time, heart-only transplant procedures with dLVAD (n = 2,636) compared with IABP (n = 571) at the time of transplant based on data from the United Network for Organ Sharing (UNOS) July 2004 to December 2011. There was clear geographic variation in IABP and dLVAD at transplant. Multivariable analysis demonstrated equivalent cumulative risk of death (adjusted Cox proportional hazard ratio, 1.08; 95% confidence interval, 0.87-1.33; p = 0.51). There was no significant difference in adjusted comparison of perioperative morality, length of stay, postoperative renal failure requiring dialysis, or early acute rejection (p ≥ 0.14 for all). Therefore, data from UNOS suggest that the presence of dLVAD at the time of heart transplantation does not have a detrimental effect on postoperative outcomes compared with IABP, which must be considered in the context of pretransplant mortality and locoregional organ availability.

Current Status of Left Ventricular Assist Device Therapy

Congestive heart failure (HF) remains a serious burden in the Western World. Despite advances in pharmacotherapy and resynchronization, many patients have progression to end-stage HF. These patients may be candidates for heart transplant or left ventricular assist device (LVAD) therapy. Heart transplants are limited by organ shortages and in some cases by patient comorbidities; therefore, LVAD therapy is emerging as a strategy of bridge to transplant or as a destination therapy in patients ineligible for transplant. Patients initially ineligible for a transplant may, in certain cases, become eligible for transplant after physiologic improvement with LVAD therapy, and a small number of patients with an LVAD may have sufficient recovery of myocardial function to allow device explantation. This clinically oriented review will describe (1) the most frequently used pump types and aspects of the continuous-flow physiology and (2) the clinical indications for and the shift toward the use of LVADs in less sick patients with HF. Additionally, we review complications of LVAD therapy and project future directions in this field. We referred to the Interagency Registry for Mechanically Assisted Circulatory Support, landmark trials, and results from recently published studies as major sources in obtaining recent outcomes, and we searched for related published literature via PubMed. This review focuses primarily on clinical practice for primary care physicians and non-HF cardiologists in the United States.

Early feasibility testing and engineering development of a sutureless beating heart connector for left ventricular assist devices

APK Advanced Medical Technologies (Atlanta, GA) is developing a sutureless beating heart (SBH) left ventricular assist device (LVAD) connector system consisting of anchoring titanium coil, titanium cannula with integrated silicone hemostatic valve, coring and delivery tool, and LVAD locking mechanism to facilitate LVAD inflow surgical procedures. Feasibility testing was completed in human cadavers (n = 4) under simulated normal and hypertensive conditions using saline to observe seal quality in degraded human tissue and assess anatomic fit; acutely in ischemic heart failure bovine model (n = 2) to investigate short-term performance and ease of use; and chronically for 30 days in healthy calves (n = 2) implanted with HeartWare HVAD to evaluate performance and biocompatibility. Complete hemostasis was achieved in human cadavers and animals at LV pressures up to 170 mm Hg. In animals, off-pump (no cardiopulmonary bypass) anchoring of the connector was accomplished in less than 1 minute with no residual bleeding after full delivery and locking of the LVAD; and implant of connector and LVAD were successfully completed in under 10 minutes with total procedure blood loss less than 100 ml. In chronic animals before necropsy, no signs of leakage or disruption at the attachment site were observed at systolic LV pressures >200 mm Hg.

Complex wound management in ventricular assist device (VAD) patients: the role of aggressive debridement and vascularized soft tissue coverage

BACKGROUND

Infections and complex wounds after ventricular assist device (VAD) placement can result in significant morbidity and mortality. The purpose of this study was to evaluate complex wound management in the VAD patient, and to describe a treatment protocol for these challenging and potentially mortal complications.

METHODS

A retrospective study was performed to examine all patients who underwent continuous flow, second-generation VAD placement at the Hospital of the University of Pennsylvania between March 2008 and April 2013.

RESULTS

Overall, 150 VADs were placed, with 12 (8%) patients requiring 15 operative interventions by the plastic surgery services. The most common indication for operative intervention was a complicated wound with VAD exposure (5/12, 41.7%). All patients underwent aggressive operative debridement, and 11/12 (92%) underwent vascularized soft tissue coverage. Flaps commonly utilized included rectus abdominus myocutaneous (n = 4), rectus abdominus muscle (n = 4), pectoralis major (n = 3), and omentum (n = 3). Three patients experienced complications which required a return to the operating room, including 1 flap loss, 1 hematoma, and 1 wound dehiscence requiring further soft tissue coverage. Salvage was achieved, yet a 50% mortality rate in follow-up was noted.

CONCLUSION

Complex wound management in VAD patients can be achieved with aggressive debridement and vascularized soft tissue coverage, most commonly utilizing well-vascularized rectus abdominus muscle or omental flaps. Plastic surgeons should be familiar with the armamentarium at their disposal when approaching these challenging cases as VAD wound complications stand to become an increasingly prevalent issue.

Physiologic and hematologic concerns of rotary blood pumps: what needs to be improved?

Over the past few decades, advances in ventricular assist device (VAD) technology have provided a promising therapeutic strategy to treat heart failure patients. Despite the improved performance and encouraging clinical outcomes of the new generation of VADs based on rotary blood pumps (RBPs), their physiologic and hematologic effects are controversial. Currently, clinically available RBPs run at constant speed, which results in limited control over cardiac workload and introduces blood flow with reduced pulsatility into the circulation. In this review, we first provide an update on the new challenges of mechanical circulatory support using rotary pumps including blood trauma, increased non-surgical bleeding rate, limited cardiac unloading, vascular malformations, end-organ function, and aortic valve insufficiency. Since the non-physiologic flow characteristic of these devices is one of the main subjects of scientific debate in the literature, we next emphasize the latest research regarding the development of a pulsatile RBP. Finally, we offer an outlook for future research in the field.

Long-term paracorporeal ventricular support systems: a single-center experience

BACKGROUND

The Berlin Heart EXCOR is a first-generation paracorporeal, pneumatic ventricular assist device that creates pulsatile flow. It can be used for long-term support of the left and/or right ventricule during end-stage heart failure. The aim of this study was to share our clinical experience in 54 patients.

METHODS

Between April 2007 and August 2012, 54 patients with end-stage heart failure underwent Berlin Heart EXCOR ventricular assist device implantation, including 5 females and 9 children. Twenty-four patients (44%) were in Intermacs level 1, 11 (21%) in level 2, and 19 (35%) in level 3. Biventricular support was applied to 13 patients. Device implantation was performed with an "on pump" beating heart technique while 6 other patients underwent intervention operations while the aortic valve has under cross-clamp. Tricuspid annuloplasty was performed in 6 patients.

RESULTS

There was no peroperative death. Nine patients (17%) underwent re-exploration because of hemorrhage in the early postoperative period. Heart transplantation was performed in 32 patients (59%), while 10 (19%) are still under pump support with a mean follow-up of 13 months. Although 1 was successfully weaned from the system, 11 patients (20%) died during the support. Pump-head exchange was required 19 times in 17 patients because of visible thrombus or fibrin deposit in the pump head or due to membrane rupture.

DISCUSSION

The use of long-term paracorporeal assist devices has decreased in recent years because of the increased popularity of implantable devices that permit longer survival and a better quality of life. We believe that the Berlin Heart EXCOR has a special role because it can be used in pediatric patients and especially in critical conditions like Intermacs levels 1 and 2.

Heart transplantation and left ventricular assist device therapy: two comparable options in end-stage heart failure?

Heart transplantation is the only curative therapy for chronic heart failure, and it plays an important role in the treatment of chronic heart failure with a survival rate of approximately 50% of all patients after 10 years. This has to be kept in mind when alternative therapies enter into our daily routine in treating this patient population. However, the shortage of appropriate donor organs and the expanding pool of patients waiting for heart transplantation have led to growing interest in alternative strategies, particularly in left ventricular assist device (LVAD) therapy. With growing clinical experience and continued technical advances, continuous-flow pumps are evolving as a bridge to transplantation or as a destination therapy for advanced heart failure. Nevertheless, the importance of this new indication of chronic cardiac support compared to heart transplantation is still completely open and the object of controversial ongoing discussion. This review (1) describes the clinical use and long-term outcome of a currently available miniaturized LVAD in the context to the standard of care-heart transplantation, (2) provides an outlook of the ongoing process of further optimization of LVADs, and (3) comments on the challenges with assist devices as alternatives to transplantation with a 5-year outlook.

To bridge or not to bridge?

OBJECTIVE

Ventricular assist devices (VAD) are an important therapy that saves the lives of candidates a waiting heart transplantation (HTx). However, there are questions about posttransplantation effects of VADs.

METHODS

Seventy-four patients with end-stage heart failure who underwent HTx in our clinic between February 2007 and July 2011 were divided into two groups; a bridge cohort (n = 28) and a nonbridge group comprising 46 who underwent HTx without mechanical circulatory support. There mean ages were 39.89 ± 15.66 and 38.33 ± 16.23 years respectively. Significantly more patients in the bridge group, were man displayed anemia, were treated with anticoagulation therapy, and underwent a resternotomy. In the nonbridge group, more patients needed preoperative inotropic support.

RESULTS

Multiple logistic regression analysis revealed preoperative renal failure (P = .007, odds ratio [OR] 27) and inotropic support (P = .006, OR: 10,222) as well as longer cardiopulmonary bypasses (≥ 130 minutes, P = .001, OR: 11,24) to be risk factors for in-hospital mortality, which was 15.2% in nonbridge and 10.7% in bridge subjects, P = .733). Major adverse events, such as renal failure, pulmonary failure, right ventricular failure, neurological event, and reoperation due to bleeding, shown similar incidences between the groups. The amount of blood transfusion was significantly higher in the bridge group (2.34 U versus 3.56 U, P = .037). The preoperative incidence of human leukocyte antigen sensitization (panel reactive antibody ≥ 10%) and grade 2R were rejection episodes in the early period were similar.

CONCLUSION

Early posttransplant results were not adversely or beneficially influenced by the use of VADs. Similar to other types of cardiac surgery, a patients preoperative condition seemed to be the major factor affecting mortality.

Right ventricular dysfunction following continuous flow left ventricular assist device placement in 51 patients: predicators and outcomes

BACKGROUND

Right ventricular (RV) dysfunction following implantation of a left ventricular assist device (LVAD) is a serious condition and is associated with increased mortality.

METHODS

The aim of the study is to investigate the significance of pre-existing RV dysfunction, tricuspid valve (TV) insufficiency, and the severity of septal deviation following LVAD implantation on RV dysfunction, as well as the outcome and short-term complications in 51 patients from June 2006 to August 2010. Student t test was used to compare the data and estimate the p value.

RESULTS

Mean age was 55.1 ± 13, with a male to female ratio of 3.25. The 30-day mortality was 13.7% (7/51 patients), and the overall mortality was 23.5% (12/51 patients). Meanwhile, 21 patients (21/51; 41.2%) have undergone orthotopic heart transplantation. The mean time of support was 314.5±235 days with a median of 240 days at the time of closing this study. Echocardiographic evaluation of RV function pre- and post-implantation of an LVAD demonstrated septal deviation towards the left ventricle in immediate postoperative phase, which correlated with acute RV dysfunction (p = 0.002). Preoperative RV dysfunction was a significant predictor of postoperative right heart dysfunction following implantation of an LVAD (p = 0.001).

CONCLUSION

Preoperative RV dysfunction is a predictor of RV failure in LVAD patients. The adjustment of septal deviation through gradual increase of the LVAD flow can prevent the acute RV dysfunction following LVAD placement.

Miniaturization of left ventricular assist devices: the ongoing trend

The shortage of appropriate donor hearts and the expanding pool of patients waiting for a heart transplantation have led to growing interest in alternative strategies, particularly in mechanical circulatory support. With expanding clinical experience and continued technical advances, continuous-flow pumps are evolving from bridge to transplantation to destination therapy for advanced heart failure. This review describes the clinical use and outcome of currently available miniaturized left ventricular assist devices (LVADs). It provides an outlook of the ongoing process of the miniaturization of LVADs, new concepts of partial support and, furthermore, it commentates on the current challenges with LVADs and the 5-year perspective.