Cardiac transplantation after bridged therapy with continuous flow left ventricular assist devices

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.

Outcomes of Heart Transplant Donation After Circulatory Death

BACKGROUND

Heart transplantation using donation after circulatory death (DCD) allografts is increasingly common, expanding the donor pool and reducing transplant wait times. However, data remain limited on clinical outcomes.

OBJECTIVES

We sought to compare 6-month and 1-year clinical outcomes between recipients of DCD hearts, most of them recovered with the use of normothermic regional perfusion (NRP), and recipients of donation after brain death (DBD) hearts.

METHODS

We conducted a single-center retrospective observational study of all adult heart-only transplants from January 2020 to January 2023. Recipient and donor data were abstracted from medical records and the United Network for Organ Sharing registry, respectively. Survival analysis and Cox regression were used to compare the groups.

RESULTS

During the study period, 385 adults (median age 57.4 years [IQR: 48.0-63.7 years]) underwent heart-only transplantation, including 122 (32%) from DCD donors, 83% of which were recovered with the use of NRP. DCD donors were younger and had fewer comorbidities than DBD donors. DCD recipients were less often hospitalized before transplantation and less likely to require pretransplantation temporary mechanical circulatory support compared with DBD recipients. There were no significant differences between groups in 1-year survival, incidence of severe primary graft dysfunction, treated rejection during the first year, or likelihood of cardiac allograft vasculopathy at 1 year after transplantation.

CONCLUSIONS

In the largest single-center comparison of DCD and DBD heart transplantations to date, outcomes among DCD recipients are noninferior to those of DBD recipients. This study adds to the published data supporting DCD donors as a safe means to expand the heart donor pool.

Continuous-flow left ventricular assist device versus orthotopic heart transplantation in adults with heart failure: a systematic review and meta-analysis

Background

Due to the lack of donor hearts, many studies have assessed the prognosis of heart failure (HF) patients treated with a continuous-flow left ventricular assist device (CF-LVAD). However, previous results have not been consistent and minimal data is available regarding long-term outcomes. There is no consensus on whether CF-LVAD as a bridge or destination therapy (DT) can equal orthotopic heart transplantation (HTx). The purpose of our study is to compare clinical outcomes between CF-LVAD and HTx in adults.

Methods

We searched controlled trials from PubMed, Cochrane Library, and Embase databases until July 1, 2020. The mortality at different time points and adverse events were analyzed among 12 included studies.

Results

No significant differences were found in mortality at one-year [odds ratio (OR) =1.08; 95% CI: 0.97-1.21], two-year (OR =1.01; 95% CI: 0.91-1.12), three-year (OR =1.02; 95% CI: 0.69-1.51), and five-year (OR =1.02; 95% CI: 0.93-1.11), as well as the comparison of stroke, bleeding, and infection between CF-LVAD as a bridge versus HTx. The pooled analysis of one-year mortality (OR =2.76; 95% CI: 0.38-20.18) and two-year mortality (OR =1.64; 95% CI: 0.22-12.23) revealed no significant difference between CF-LVAD DT and HTx. Comparisons of adverse events showed no differences in bleeding or infection, but a higher risk of stroke (OR =5.09; 95% CI: 1.74-14.84) for patients treated with CF-LVAD DT than with HTx.

Conclusions

CF-LVAD as a bridge results in similar outcomes as HTx within five years. CF-LVAD as a DT is associated with similar one-year and two-year mortality, but carries a higher risk of stroke, as compared with HTx.

Heart transplantation of patients with ventricular assist devices: impact of normothermic ex-vivo preservation using organ care system compared with cold storage

Background

Organ Care System (OCS) minimizes the cold ischemic time and allows for optimization of logistics and meticulous recipient preparation. Impact of normothermic ex-vivo preservation using OCS compared with cold storage (CS) for prolonged heart preservation especially beneficial for high-risk recipients bridged to transplantation with Mechanical Circulatory Support (MCS).

Methods

Between 2012 and 2018, we performed a retrospective single-center review of prospectively collected data. All patients who underwent heart transplantation with MCS using the OCS Heart (n = 25) versus standard cold storage (n = 10) were included in this study.

Results

During this period, 353 patients were implanted with left ventricular assisted device (LVAD) and 35 (10%) were bridged to heart transplantation. There was no significant difference in donor and recipient characteristics and risk factors. The Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score was a trend towards higher estimated risk of death at 1y in the OCS group (14.2 vs. 10.8% p = 0.083). Mean total ischemic time during preservation was statistically significantly longer in CS vs OCS group (210 (23) Vs 74.6 (13) min p = 0.001). Median ex vivo normothermic heart perfusion time in OCS was 348.4(132; 955) min. There was significant difference in total out of body time between OCS group 423(67) Vs CS group 210(23) min p = 0.002). All patients were alive on the 30th days post implant in CS groups and 96% in OCS group (p = 0.5).

Conclusion

Normothermic ex-vivo preservation of the allograft during transportation with the organ care system might be beneficial for long-time out of body organ preservation in comparison of cold storage especially for recipients on mechanical circulatory support.

Heart Transplantation After Ventricular Assist Device Therapy: Benefits, Risks, and Outcomes

Heart transplantation is an established treatment for end-stage heart failure. Due to the increase in demand and persistent scarcity of organ, mechanical circulatory devices have played a major role in therapy for advanced heart failure. Usage of left ventricular assist device (LVAD) has gone up from 6% in 2006 to 43% in 2013 as per the United Network of Organ Sharing database. Majority of patients presenting for a heart transplantation are often bridged with an assist device prior for management of heart failure while on wait-list. On one hand, it is well established that LVADs improve survival on wait-list; on the other hand, the effect of LVAD on morbidity and survival after a heart transplantation is still unclear. In this article, we review the available literature and attempt to infer the outcomes given the risks and benefits of heart transplantation with prior LVAD patients.

Long-term prognosis and cost-effectiveness of left ventricular assist device as bridge to transplantation: A systematic review

BACKGROUND

This systematic review aimed to evaluate the clinical outcomes and cost-effectiveness of left ventricular assist devices (LVADs) used as bridge to transplantation (BTT), compared to orthotopic heart transplantation (OHT) without a bridge.

METHOD

Systematic searches were performed in electronic databases with available data extracted from text and digitized figures. Meta-analysis of short and long-term term post-transplantation outcomes was performed with summation of cost-effectiveness analyses.

RESULTS

Twenty studies reported clinical outcomes of 4575 patients (1083 LVAD BTT and 3492 OHT). Five studies reported cost-effectiveness data on 837 patients (339 VAD BTT and 498 OHT). There was no difference in long-term post-transplantation survival (HR 1.24, 95% CI 1.00-1.54), acute rejection (HR 1.10, 95% CI 0.93-1.30), or chronic rejection and cardiac allograft vasculopathy (HR 0.99, 95% CI 0.73-1.36). No differences were found in 30-day post-operative mortality (OR 0.91, 95% CI 0.42-2.00), stroke (OR 1.64, 95% CI 0.43-6.27), renal failure (OR 1.43, 95% CI 0.58-3.54), bleeding (OR 1.56, 95% CI 0.78-3.13), or infection (OR 2.44, 95% CI 0.81-7.38). Three of the five studies demonstrated incremental cost-effectiveness ratios below the acceptable maximum threshold. The total cost of VAD BTT ranged from $316,078 to $1,025,500, and OHT ranged from $179,051 to $802,200.

CONCLUSION

LVADs used as BTT did not significantly alter post-transplantation long-term survival, rejection, and post-operative morbidity. LVAD BTT may be cost-effective, particularly in medium and high-risk patients with expected prolonged waiting times, renal dysfunction, and young patients.

Optimal timing of same-admission orthotopic heart transplantation after left ventricular assist device implantation

AIM

To investigate the impact of timing of same-admission orthotopic heart transplant (OHT) after left ventricular assist device (LVAD) implantation on in-hospital mortality and post-transplant length of stay.

METHODS

Using data from the Nationwide Inpatient Sample from 1998 to 2011, we identified patients 18 years of age or older who underwent implantation of a LVAD and for whom the procedure date was available. We calculated in-hospital mortality for those patients who underwent OHT during the same admission as a function of time from LVAD to OHT, adjusting for age, sex, race, household income, and number of comorbid diagnoses. Finally, we analyzed the effect of time to OHT after LVAD implantation on the length of hospital stay post-transplant.

RESULTS

Two thousand and two hundred patients underwent implantation of a LVAD in this cohort. One hundred and sixty-four (7.5%) patients also underwent OHT during the same admission, which occurred on average 32 d (IQR 7.75-66 d) after LVAD implantation. Of patients who underwent OHT, patients who underwent transplantation within 7 d of LVAD implantation (“early”) experienced increased in-hospital mortality (26.8% vs 12.2%, P = 0.0483) compared to patients who underwent transplant after 8 d (“late”). There was no statistically significant difference in age, sex, race, household income, or number of comorbid diagnoses between the early and late groups. Post-transplant length of stay after LVAD implantation was also not significantly different between patients who underwent early vs late OHT.

CONCLUSION

In this cohort of patients who received LVADs, the rate of in-hospital mortality after OHT was lower for patients who underwent late OHT (at least 8 d after LVAD implantation) compared to patients who underwent early OHT. Delayed timing of OHT after LVAD implantation did not correlate with longer hospital stays post-transplant.

Effect of Pretransplant Continuous-Flow Left Ventricular Assist Devices on Cellular and Antibody-Mediated Rejection and Subsequent Allograft Outcomes

The aim of this study was to evaluate the impact of continuous-flow left ventricular assist devices (CF-LVAD) on subsequent rejection after heart transplantation (HT) by using cellular rejection score and antibody-mediated rejection score (AMRS) and correlating with subsequent allograft outcomes. We retrospectively analyzed 108 consecutive patients who underwent HT without (n = 67) or with (n = 41) previous CF-LVAD in 2008 to 2014. The 24 months cumulative effect of rejection was calculated by using cellular rejection scores and AMRS, based on the total number of rejections divided by valid biopsy samples. Vasculopathy was assessed both by routine coronary angiogram and intravascular ultrasound. Patients who underwent pretransplant CF-LVAD demonstrated a significant increase in the number of cellular rejection episodes as compared with the nonbridged patients, for 1 and 2 years of follow-up (p = 0.026 and p = 0.016), respectively. There were no differences in AMRS (p >0.05) and allograft outcomes, such as vasculopathy and overall survival (p >0.05) over the period of follow-up. Implantation of a CF-LVAD before HT impacts cellular rejection during the post-transplant period. Despite these findings, CF-LVAD does not translate to differences in allograft outcomes after transplant, such as vasculopathy and overall survival over the period of the study. In conclusion, whether this affects longer term outcomes than studied remains to be determined.

Heart Transplant in Asia

The prevalence of heart failure has increased in Asia. A significant proportion of patients with heart failure and left ventricular dysfunction end up with advanced heart failure or end-stage heart disease. These patients may be placed on the waiting list for heart transplant. There are more than 10 countries in Asia that have an active heart transplant program. The number of heart transplants performed is limited despite an increase in the number of patients with end-stage heart failure mainly because of donor shortage, which may be related to religious belief and inefficient allocation policy.

Early postoperative management of heart transplant recipients with current ventricular assist device support in Japan: experience from a single center

PURPOSE

This study reviews our experience with the perioperative management of heart transplant (HT) recipients and explores how prior ventricular assist device (VAD) support affects the requirements for postoperative mechanical ventilation and circulatory support.

METHODS AND RESULTS

A retrospective database review was performed from 2007 to 2014. Early postoperative outcomes were compared between VAD and non-VAD groups. Forty-four patients were studied. The mean age was 38 ± 13 years, 30% were female, and 88% experienced non-ischemic heart failure. Forty patients (91%) required VAD support at the time of HT, with a mean duration of 864 ± 351 days. The median postoperative mechanical ventilation times in the VAD and non-VAD groups were 54 [95% confidence interval (CI) 42.9-297.3] and 15 (95% CI 4.8-30.0; p = 0.0199) hours, respectively. The VAD group experienced increased bleeding during the first 48 h after HT (6.7 ± 3.5 vs. 1.8 ± 0.75 l, p = 0.004). Mechanical circulatory support with intra-aortic balloon pumping or venoarterial extracorporeal membrane oxygenation was required in 30% of VAD group patients. Increased bleeding and primary graft failure were the main causes of prolonged mechanical ventilation.

CONCLUSIONS

HT recipients with VAD support required longer mechanical ventilation periods and mechanical circulatory support in the postoperative period.

Long-term continuous-flow left ventricular assist devices (LVAD) as bridge to heart transplantation

Heart transplantation (HTx) is the treatment of choice for end-stage heart failure but the limited availability of heart's donors still represents a major issue. So long-term mechanical circulatory support (MCS) has been proposed as an alternative treatment option to assist patients scheduled on HTx waiting list bridging them for a variable time period to cardiac transplantation-the so-called bridge-to-transplantation (BTT) strategy. Nowadays approximately 90% of patients being considered for MCS receive a left ventricular assist device (LVAD). In fact, LVAD experienced several improvements in the last decade and the predominance of continuous-flow over pulsatile-flow technology has been evident since 2008. The aim of the present report is to give an overview of continuous-flow LVAD utilization in the specific setting of the BTT strategy taking into consideration the most representative articles of the scientific literature and focusing the attention on the evolution, clinical outcomes, relevant implications on the HTx strategy and future perspectives of the continuous-flow LVAD technology.

Late right heart failure during support with continuous-flow left ventricular assist devices adversely affects post-transplant outcome

BACKGROUND

Right heart failure (RHF) is an unresolved issue during continuous-flow left ventricular assist device (LVAD) support. Little is known about post-transplant outcomes in patients complicated by late RHF during LVAD support.

METHODS

Between May 2004 and December 2013, 141 patients underwent cardiac transplantation after isolated LVAD bridging at our center. Late RHF was defined as heart failure requiring medical intervention >4 weeks after LVAD implantation.

RESULTS

The patients' mean age was 53 ± 13 years, 82% were men, and 36% had an ischemic etiology. The mean duration of LVAD support before transplantation was 0.75 years. Late RHF developed in 21 patients (15%) during LVAD support. Of these patients, 11 were supported with inotropic agents at the time of transplantation. Patients with RHF had higher creatinine (1.6 ± 0.88 mg/dL vs 1.3 ± 0.67 mg/dL, p = 0.07), higher blood urea nitrogen (32 ± 17 mg/dL vs 24 ± 10 mg/dL, p = 0.0013), higher total bilirubin (0.96 ± 0.46 mg/dL vs 0.78 ± 0.42 mg/dL, p = 0.07), and lower albumin (3.8 ± 0.60 g/dL vs 4.1 ± 0.46 g/dL, p = 0.0019) at the time of transplantation compared with patients who did not develop RHF. In-hospital mortality was significantly higher in patients with late RHF during LVAD support (29% vs 6.7%, p = 0.002). Overall post-transplant survival rates were 87% at 1 year, 83% at 3 years, and 77% at 5 years. The 5-year post-transplant survival was significantly worse in patients who developed late RHF during LVAD support compared with survival in patients who did not develop RHF (26% vs 87%, p < 0.0001).

CONCLUSIONS

Late RHF during LVAD support adversely affects post-transplant survival.

Outcome of cardiac transplantation in patients requiring prolonged continuous-flow left ventricular assist device support

OBJECTIVE

This study assessed the early and late outcomes after cardiac transplantation in patients receiving long-term continuous-flow left ventricular assist device (CF-LVAD) support.

METHODS

Between April 2004 and September 2013, 192 patients underwent HeartMate II (Thoratec, Pleasanton, CA) CF-LVAD placement as a bridge to transplant at our center. Of these, 122 (63%) successfully bridged patients were retrospectively reviewed. Patients were stratified into 2 groups according to their waiting time with CF-LVAD support of <1 year or ≥1 year.

RESULTS

The study cohort was a mean age of 54 ± 13 years, 79% were male, and 35% had an ischemic etiology. The mean duration of CF-LVAD support before transplantation was 296 days (range, 27-1,413 days). The overall 30-day mortality was 4.1%. Overall post-transplant survival was 88%, 84%, 78% at 1, 3, and 5 years, respectively. The 32 patients (26%) with ≥1 year of CF-LVAD support (mean, 635 days) were more likely to have blood type O, a larger body size, and to have been readmitted due to recurrent heart failure and device failure requiring exchange than those with <1 year of CF-LVAD support. Patients who required prolonged support time also had worse in-hospital mortality (16% vs 6.7%, p = 0.12) and significantly lower survival at 3 years after transplantation (68% vs 88%, p = 0.049).

CONCLUSIONS

The overall short-term and long-term cardiac transplant outcomes of patients supported with CF-LVAD are satisfactory. However, patients who require prolonged CF-LVAD support may have diminished post-transplant survival due to adverse events occurring during device support.

Does renal dysfunction and method of bridging support influence heart transplant graft survival?

BACKGROUND

Renal insufficiency is common in status 1B patients supported with inotropes or a continuous flow left ventricular device (CF-LVAD) as a bridge to heart transplantation. We evaluated the association of renal function and inotrope versus CF-LVAD support on posttransplant graft survival in status 1B patients.

METHODS

The Scientific Registry for Transplant Recipients database was analyzed for posttransplant survival in status 1B patients bridged with inotropes or CF-LVAD who underwent transplantation between 2003 and 2012. Pretransplant renal function was measured by estimating glomerular filtration rate (GFR) and was stratified as less than 45 mL · min(-1) · 1.73 m(-2), 45 to 59, and 60 or greater. Univariate Kaplan-Meier and multivariate Cox regression models were used to evaluate the main effects of GFR strata and inotropes versus CF-LVAD, and the interaction effect of GFR strata by CF-LVAD, on graft survival.

RESULTS

This study included 4,158 status 1B patients (74% male, aged 53 ± 12 years). Of those, 659 patients had a CF-LVAD (HeartMate-II [Thoratec, Pleasanton, CA], n = 638; HVAD [HeartWare, Framingham, MA], n = 21), and 3,530 were receiving inotropes (31 CF-LVAD patients were also receiving inotropes). Kaplan-Meier analyses demonstrated reduced graft survival (p = 0.022) in patients with pretransplant GFR less than 45 versus GFR 45 to 59 (p = 0.062) and versus GFR 60 or greater (p = 0.007), and no effect of inotrope versus CF-LVAD support on graft survival (p = 0.402). Multivariate analysis demonstrated that, after adjusting for the main effects of GFR stratum, CF-LVAD, and inotropes, status 1B patients bridged with a CF-LVAD and GFR in the lowest stratum had reduced graft survival (interaction effect p = 0.040).

CONCLUSIONS

Pretransplant renal insufficiency was associated with reduced posttransplant graft survival in status 1B patients. This risk is increased for patients bridged with a CF-LVAD (versus inotropes) who have GFR in the lowest stratum.