Competing Risks to Transplant in Bridging with Continuous Flow Left Ventricular Assist Devices

Escalating Surgical Treatment for Left Ventricular Assist Device Infection and Expected Mortality: Clinical Risk Prediction Score

BACKGROUND

Left ventricular assist devices (LVAD) improve survival for patients with cardiac failure, but LVAD-specific infection (VSI) remains a challenge with poorly understood predictive risk factors. The indications and use of escalating medical treatment to surgical debridement and potential flap reconstruction are not well characterized.

STUDY DESIGN

A retrospective review of consecutive patients undergoing primary LVAD implantation at a tertiary academic center was performed. The primary outcome measures were 90-day and overall mortality after VSI. Cox proportional hazards regression was used to generate a risk prediction score for mortality.

RESULTS

Of the 760 patients undergoing primary LVAD implantation, 255 (34%) developed VSI; of these patients, 91 (36%) were managed medically, 134 (52%) with surgical debridement, and 30 (12%) with surgical debridement and flap reconstruction. One-year survival after infection was 85% with median survival of 2.40 years. Factors independently associated with increased mortality were diabetes (hazard ratio [HR] 1.44, p = 0.04), MRSA infection (HR 1.64, p = 0.03), deep space (pump pocket or outflow cannula) involvement (HR 2.26, p < 0.001), and extracorporeal membrane oxygenation after LVAD (HR 2.52, p < 0.01). Factors independently associated with decreased mortality were flap reconstruction (HR 0.49, p = 0.02) and methicillin-sensitive Staphylococcus aureus infection (HR 0.63, p = 0.03). A clinical risk prediction score was developed using these factors and showed significant differences in median survival, which was 5.67 years for low-risk (score 0 to 1), 3.62 years for intermediate-risk (score 2), and 1.48 years for high-risk (score ≥3; p < 0.001) patients.

CONCLUSIONS

We developed a clinical risk prediction score to stratify patients with VSI. In selected cases, escalating surgical treatment was associated with increased survival. Future work is needed to determine whether early surgical debridement and flap reconstruction can alter outcomes in select cases of VSI.

Days Alive and Out of the Hospital After Heart Transplantation: A Retrospective Cohort Study

OBJECTIVE

Evaluate days alive and out of the hospital (DAOH) as an outcome measure after orthotopic heart transplantation in patients with mechanical circulatory support (MCS) as a bridge to transplant compared to those patients without prior MCS.

DESIGN

A retrospective observational study of adult patients who underwent cardiac transplantation between January 1, 2015, and January 1, 2020. The primary outcome was DAOH at 365 days (DAOH365) after an orthotopic heart transplant. A Poisson regression model was fitted to detect the association between independent variables and DAOH365.

SETTING

An academic tertiary referral center.

PARTICIPANTS

A total of 235 heart transplant patients were included-103 MCS as a bridge to transplant patients, and 132 direct orthotopic heart transplants without prior MCS.

MEASUREMENTS AND MAIN RESULTS

The median DAOH365 for the entire cohort was 348 days (IQR 335.0-354.0). There was no difference in DAOH365 between the MCS patients and patients without MCS (347.0 days [IQR 336.0-353.0] v 348.0 days [IQR 334.0-354.0], p = 0.43). Multivariate analysis identified patients who underwent a transplant after the 2018 heart transplant allocation change, pretransplant pulmonary hypertension, and increased total ischemic time as predictors of reduced DAOH365.

CONCLUSIONS

In this analysis of patients undergoing orthotopic heart transplantation, there was no significant difference in DAOH365 in patients with prior MCS as a bridge to transplant compared to those without MCS. Incorporating days alive and out of the hospital into the pre-transplant evaluation may improve understanding and conceptualization of the post-transplantation patient experience and aid in shared decision-making with clinicians.

Waitlist Trends in Heart-Liver Transplantation With Updated US Heart Allocation System

BACKGROUND

In October 2018, the United States implemented a change in the donor heart allocation policy from a three-tiered to a six-tiered status system. The purpose of the current study was to examine changes in waitlist patterns among patients listed for concomitant heart-liver transplantation with implementation of the new allocation system.

METHODS

Patients listed for heart-liver transplantation between January 1, 2012, and June 30, 2021, were identified from the United Network for Organ Sharing database. Patients were grouped by era according to initial list date before or after October 18, 2018. Competing risks regression for mortality, transplantation, removal from waitlist due to illness was performed according to the method of Fine and Gray. Waitlist data were censored at 3 years from initial listing.

RESULTS

Overall, 523 patients were identified, of whom 310 were listed before (era 1, 59%) and 213 after (era 2, 41%) allocation change. Patients in era 1 were older, had more restrictive cardiomyopathy, and more preoperative inotrope use (all P < .05). However, patients in era 2 has longer ischemic times (3.5 ± 1.1 vs 3.1 ± 1.1 hours, P < .01) and more intraaortic balloon pump use (8.9% vs 3.9%, P = .016). Era 2 was associated with lower subdistribution hazard for death (hazard ratio 0.37; 95% CI, 0.13-1.02; P = .054) and increased transplantation (hazard ratio 1.35; 95% CI, 1.06-1.72; P = .015).

CONCLUSIONS

The implementation of the US donor heart allocation policy was associated with more preoperative intraaortic balloon pump use for patients listed for heart-liver transplantation. Despite that, the modern era was associated with lower waitlist mortality and more frequent transplantation, without increased risk of delisting due to illness.

Is it time to stop living in a HeartMate II world?

Despite improving outcomes with modern pump technology, left ventricular assist device (LVAD) utilization for patients with end-stage heart failure (HF) has declined significantly in the preceding half-decade. Here, we examine this trend, noting an inherent contradiction in the declining utilization of an improving therapeutic option. We propose a series of provocative questions as a "call to action" for the field of advanced HF to consider both scientifically and clinically, focusing on our evaluation parameters for LVAD candidacy, our approach to dichotomous LVAD vs transplant decisions, and our current management paradigms. We conclude that modernization in these areas to match the advantages of modern pump technology is required to best serve patients with advanced HF.

Durable mechanical circulatory support as bridge to heart transplantation

PURPOSE OF REVIEW

Durable mechanical circulatory support (MCS) technology has changed over time as devices have evolved from pulsatile to continuous flow support. In this review, we discuss recent data and substantial changes to current practice as it pertains to the subject of current era durable left ventricular assist devices (LVADs) as a bridge to heart transplantation.

RECENT FINDINGS

The results of heart transplantation in patients bridged with durable LVAD support are satisfactory even after prolonged duration of support. Reports of recent experience with LVAD related infection suggest that this complication has limited impact on post-transplant outcomes. Important sex-related disparities continue to exist following durable LVAD implantation. Recent changes in the United Network for Organ Sharing donor heart allocation policy have resulted in a drastic decline in the use of durable LVAD support for Bridge to Transplant in the United States.

SUMMARY

Durable MCS in the form of LVAD as a BTT strategy continues to evolve over time. Optimization of its role in the treatment of end-stage heart failure, particularly in females will need to be the focus of future research.