How does successful bridging with ventricular assist device affect cardiac transplantation outcome?

Clinical Outcomes of Early Extubation Strategy in Patients Undergoing Extracorporeal Membrane Oxygenation as a Bridge to Heart Transplantation

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) might be considered a bridge therapy in patients who are expected to have short waiting times for heart transplantation. We investigated the clinical outcomes of patients who underwent VA-ECMO as a bridge to heart transplantation and whether the deployment of an early extubation ECMO strategy is beneficial.

METHODS

Between November 2006 and December 2018, we studied 102 patients who received VA-ECMO as a bridge to heart transplantation. We classified these patients into an early extubation ECMO group (n = 24) and a deferred extubation ECMO group (n = 78) based on the length of the intubated period on VA-ECMO (≤ 48 hours or > 48 hours). The primary outcome was in-hospital mortality.

RESULTS

The median duration of early extubation VA-ECMO was 10.0 (4.3-17.3) days. The most common cause for patients to be put on ECMO was dilated cardiomyopathy (65.7%) followed by ischemic cardiomyopathy (11.8%). In-hospital mortality rates for the deferred extubation and early extubation groups, respectively, were 24.4% and 8.3% (P = 0.147). During the study period, in the deferred extubation group, 60 (76.9%) underwent transplantation, while 22 (91.7%) underwent transplantation in the early extubation group. Delirium occurred in 83.3% and 33.3% of patients from the deferred extubation and early extubation groups (P < 0.001) and microbiologically confirmed infection was identified in 64.1% and 41.7% of patients from the two groups (P = 0.051), respectively.

CONCLUSION

VA-ECMO as a bridge therapy seems to be feasible for deployment in patients with a short waiting time for heart transplantation. Deployment of the early extubation ECMO strategy was associated with reductions in delirium and infection in this population.

Readmission and resource utilization after orthotopic heart transplant versus ventricular assist device in the National Readmissions Database, 2010-2014

BACKGROUND

As the technology of ventricular assist devices continues to improve, the morbidity and mortality for patients with a ventricular assist device is expected to approach that of orthotopic heart transplantation. The present study was performed to compare perioperative outcomes, readmission, and resource utilization between ventricular assist device implantation and orthotopic heart transplantation, using a national cohort.

METHODS

Patients who underwent either orthotopic heart transplantation or ventricular assist device implantation from 2010 to 2014 in the National Readmission Database were selected.

RESULTS

Of the 12,111 patients identified during the study period, 5,440 (45%) received orthotopic heart transplantation, while 6,671 (55%) received ventricular assist devices. Readmissions occurred frequently after ventricular assist device implantation and orthotopic heart transplantation, with greater rates at 30 days (29% versus 24%, P=.005) and 6 months (62% versus 46%, P < .001) for the ventricular assist device cohort. Cost of readmission was greater among ventricular assist device patients at 30 days ($29,115 versus $21,586, P=.0002) and 6 months ($34,878 versus $20,144, P = .0106).

CONCLUSION

Readmission rates and costs for patients with a ventricular assist device remain greater than their orthotopic heart transplantation counterparts. Given the projected increases in ventricular assist device utilization and limited transplant donor pool, further emphasis on cost containment and decreased readmissions for patients undergoing a ventricular assist device is essential to the viability of such therapy in the era of value-based health care delivery.

Clinical outcomes of temporary mechanical circulatory support as a direct bridge to heart transplantation: a nationwide Spanish registry

BACKGROUND

In Spain, listing for high-urgent heart transplantation is allowed for critically ill candidates not weanable from temporary mechanical circulatory support (T-MCS). We sought to analyse the clinical outcomes of this strategy.

METHODS AND RESULTS

We conducted a case-by-case, retrospective review of clinical records of 291 adult patients listed for high-urgent heart transplantation under temporary devices from 2010 to 2015 in 16 Spanish institutions. Survival after listing and adverse clinical events were studied. At the time of listing, 169 (58%) patients were supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO), 70 (24%) on temporary left ventricular assist devices (T-LVAD) and 52 (18%) on temporary biventricular assist devices (T-BiVAD). Seven patients transitioned from VA-ECMO to temporary ventricular assist devices while on the waiting list. Mean time on T-MCS was 13.1 ± 12.6 days. Mean time from listing to transplantation was 7.6 ± 8.5 days. Overall, 230 (79%) patients were transplanted and 54 (18.6%) died during MCS. In-hospital postoperative mortality after transplantation was 33.3%, 11.9% and 26.2% for patients bridged on VA-ECMO, T-LVAD and T-BiVAD, respectively (P = 0.008). Overall survival from listing to hospital discharge was 54.4%, 78.6% and 55.8%, respectively (P = 0.002). T-LVAD support was independently associated with a lower risk of death over the first year after listing (hazard ratio 0.52, 95% confidence interval 0.30-0.92). Patients treated with VA-ECMO showed the highest incidence rate of adverse clinical events associated with T-MCS.

CONCLUSION

Temporary devices may be used to bridge critically ill candidates directly to heart transplantation in a setting of short waiting list times, as is the case of Spain. In our series, bridging with T-LVAD was associated with more favourable outcomes than bridging with T-BiVAD or VA-ECMO.

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.

Pediatric and congenital heart transplant: twenty-year experience in a tertiary Brazilian hospital

INTRODUCTION

Cardiac transplantation remains the gold standard for end-stage cardiomyopathies and congenital heart defects in pediatric patients.

OBJECTIVE

This study aims to report on 20 years of experience since the first case and evaluate our results.

METHODS

We conducted a retrospective analysis of the database and outpatient follow-up. Between October 1992 and April 2012, 109 patients underwent 114 transplants. 51.8% of them being female. The age of patients ranged from 12 days to 21 years with a mean of 8.8±5.7 years and a median of 5.2 years. The underlying diagnosis was dilated cardiomyopathy in 61.5%, congenital heart disease in 26.6% and restrictive cardiomyopathy in 11.9%. All patients above 17 years old had congenital heart disease.

RESULTS

Survival rate at 30 days, 1, 5, 10, 15, and 20 years were 90.4%, 81.3%, 70.9%, 60.5%, 44.4% and 26.7%, respectively. Mean cold ischemic time was 187.9 minutes and it did not correlate with mortality (P>0.05). Infectious complications and rejection episodes were the most common complications (P<0.0001), occurring, respectively, in 66% and 57.4% of the survivors after 10 years. There was no incidence of graft vascular disease and lymphoproliferative disease at year one, but they affected, respectively, 7.4% and 11% of patients within 10 years.

CONCLUSION

Twenty-year pediatric heart transplant results at our institution were quite satisfactory and complication rates were acceptable.

Ventricular assist devices and increased blood product utilization for cardiac transplantation

BACKGROUND AND AIM OF STUDY

The purpose of this study was to examine whether blood product utilization, one-year cell-mediated rejection rates, and mid-term survival significantly differ for ventricular assist device (VAD patients compared to non-VAD (NVAD) patients following cardiac transplantation.

METHODS

From July 2004 to August 2011, 79 patients underwent cardiac transplantation at a single institution. Following exclusion of patients bridged to transplantation with VADs other than the HeartMate II® LVAD (n = 10), patients were stratified by VAD presence at transplantation: VAD patients (n = 35, age: 54.0 [48.0-59.0] years) vs. NVAD patients (n = 34, age: 52.5 [42.8-59.3] years). The primary outcomes of interest were blood product transfusion requirements, one-year cell-mediated rejection rates, and mid-term survival post-transplantation.

RESULTS

Preoperative patient characteristics were similar for VAD and NVAD patients. NVAD patients presented with higher median preoperative creatinine levels compared to VAD patients (1.3 [1.1-1.6] vs. 1.1 [0.9-1.4], p = 0.004). VAD patients accrued higher intraoperative transfusion of all blood products (all p ≤ 0.001) compared to NVAD patients. The incidence of clinically significant cell-mediated rejection within the first posttransplant year was higher in VAD compared to NVAD patients (66.7% vs. 33.3%, p = 0.02). During a median follow-up period of 3.2 (2.0, 6.3) years, VAD patients demonstrated an increased postoperative mortality that did not reach statistical significance (20.0% vs. 8.8%, p = 0.20).

CONCLUSIONS

During the initial era as a bridge to transplantation, the HeartMate II® LVAD significantly increased blood product utilization and one-year cell-mediated rejection rates for cardiac transplantation. Further study is warranted to optimize anticoagulation strategies and to define causal relationships between these factors for the current era of cardiac transplantation.

Ventricular assistance devices as bridge to transplantation

The authors herein review the rationale and indications for the use of ventricular assistance devices as a bridge to heart transplantation and discuss the current evidence on the subject. The potential effects of device implantation on posttransplant outcomes and the therapeutic strategies in acute and elective cases are revised and illustrated.

Hospital costs fell as numbers of LVADs were increasing: experiences from Oslo University Hospital

Background

The current study was undertaken to examine total hospital costs per patient of a consecutive implantation series of two 3^rd generation Left Ventricle Assist Devices (LVAD). Further we analyzed if increased clinical experience would reduce total hospital costs and the gap between costs and the diagnosis related grouped (DRG)-reimbursement.

Method

Cost data of 20 LVAD implantations (VentrAssist™) from 2005-2009 (period 1) were analyzed together with costs from nine patients using another LVAD (HeartWare™) from 2009-June 2011 (period 2). For each patient, total costs were calculated for three phases - the pre-LVAD implantation phase, the LVAD implantation phase and the post LVAD implant phase. Patient specific costs were obtained prospectively from patient records and included personnel resources, medication, blood products, blood chemistry and microbiology, imaging and procedure costs including operating room costs. Overhead costs were registered retrospectively and allocated to the specific patient by predefined allocation keys. Finally, patient specific costs and overhead costs were aggregated into total hospital costs for each patient. All costs were calculated in 2011-prices. We used regression analyses to analyze cost variations over time and between the different devices.

Results

The average total hospital cost per patient for the pre-LVAD, LVAD and post-LVAD for period 1 was $ 585, 513 (range 132, 640- 1 247, 299), and the corresponding DRG- reimbursement (2009) was $ 143, 192 . The mean LOS was 54 days (range 12- 127). For period 2 the total hospital cost per patient was $ 413, 185 (range 314, 540- 622, 664) and the corresponding DRG- reimbursement (2010) was $ 136, 963. The mean LOS was 49 days (range 31- 93).

The estimates from the regression analysis showed that the total hospital costs, excluding device costs, per patient were falling as the number of treated patients increased. The estimate from the trend variable was -14, 096 US$ (CI -3, 842 to -24, 349, p < 0.01).

Conclusion

There were significant reductions in total hospital costs per patient as the numbers of patients were increasing. This can possibly be explained by a learning effect including better logistics, selection and management of patients.

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.

Risk factors for early death in patients bridged to transplant with continuous-flow left ventricular assist devices

BACKGROUND

Recent evidence suggests patients bridged to heart transplant (BTT) have equivalent outcomes as those undergoing conventional orthotopic heart transplantation (OHT). However, data on risk factors for early death in BTT patients are limited.

METHODS

We retrospectively reviewed the United Network for Organ Sharing database of all patients bridged to OHT with a HeartMate II from January 2005 to December 2010. The primary outcome was all-cause 90-day mortality. Additional postoperative outcomes were cerebrovascular accident and need for renal replacement therapy. Kaplan-Meier analysis assessed survival. Preoperative variables associated with 90-day death on univariate analysis (p<0.2) were included in a multivariable Cox proportional hazards regression.

RESULTS

A HeartMate II was used to bridge 1,312 patients (average age, 52±12 years) to OHT, most commonly for idiopathic cardiomyopathy (50.7%). During the study, 171 patients (13.0%) died. The unadjusted 90-day survival was 92.3%. The highest annual average center volume in this cohort, examining for BTT recipients only, was 28 BTT procedures yearly. Postoperative cerebrovascular accident occurred in 29 patients (2.2%), and 106 (8.3%) required renal replacement therapy. Cox regression revealed age, glomerular filtration rate, African American race, human leukocyte antigen mismatch, serum bilirubin, need for mechanical ventilation, donor age, and prolonged ischemia time were associated with 90-day death. Early survival was improved for patients who underwent OHT at high-volume centers (p=0.01).

CONCLUSIONS

This study examining risk factors for early death in patients bridged to OHT using HeartMate II mechanical assistance will aid in identifying patients best suited to benefit from this technology.