Cardiac replacement therapies: outcomes and costs for heart transplantation versus circulatory assist

Veno-arterial ECMO ventricular assistance as a direct bridge to heart transplant: A single center experience in a low-middle income country

INTRODUCTION

The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as a direct bridge to heart transplantation (BTT) is not common in adults worldwide. BTT with ECMO is associated with increased early/mid-term mortality compared with other interventions. In low- and middle-income countries (LMIC), where no other type of short-term mechanical circulatory support is available, its use is widespread and increasingly used as rescue therapy in patients with cardiogenic shock (CS) as a direct bridge to heart transplantation (HT).

OBJECTIVE

To assess the outcomes of adult patients using VA-ECMO as a direct BTT in an LMIC and compare them with international registries.

METHODS

We conducted a single-center study analyzing consecutive adult patients requiring VA-ECMO as BTT due to refractory CS or cardiac arrest (CA) in a cardiovascular center in Argentina between January 2014 and December 2022. Survival and adverse clinical events after VA-ECMO implantation were evaluated.

RESULTS

Of 86 VA-ECMO, 22 (25.5%) were implanted as initial BTT strategy, and 52.1% of them underwent HT. Mean age was 46 years (SD 12); 59% were male. ECMO was indicated in 81% for CS, and the most common underlying condition was coronary artery disease (31.8%). Overall, in-hospital mortality for VA-ECMO as BTT was 50%. Survival to discharge was 83% in those who underwent HT and 10% in those who did not, p < .001. In those who did not undergo HT, the main cause of death was hemorrhagic complications (44%), followed by thrombotic complications (33%). The median duration of VA-ECMO was 6 days (IQR 3-16). There were no differences in the number of days on ECMO between those who received a transplant and those who did not. In the Spanish registry, in-hospital survival after HT was 66.7%; the United Network of Organ Sharing registry estimated post-transplant survival at 73.1% ± 4.4%, and in the French national registry 1-year posttransplant survival was 70% in the VA-ECMO group.

CONCLUSIONS

In adult patients with cardiogenic shock, VA-ECMO as a direct BTT allowed successful HT in half of the patients. HT provided a survival benefit in listed patients on VA-ECMO. We present a single center experience with results comparable to those of international registries.

Incremental cost-effectiveness of extracorporeal membranous oxygenation as a bridge to cardiac transplant or left ventricular assist device placement in patients with refractory cardiogenic shock

Objective

Emerging literature has described using venoarterial extracorporeal membranous oxygenation (ECMO) as a bridge to transplant or left ventricular assist device (LVAD) placement. We sought to identify the incremental cost-effectiveness ratio (ICER) of ECMO used as a bridge to cardiac transplant or LVAD.

Methods

Patients with refractory cardiogenic shock who received venoarterial ECMO and were bridged to either cardiac transplant (n = 7) or a HeartMate 3 LVAD (n = 6) placement were included. Markov modeling was used, comparing ECMO bridging with non–ECMO-bridged patients. Cohorts entered the model alive and at every 1-year cycle, were exposed to risk of death, and ran forward for 20 years after transplant or LVAD.

Results

Patients bridged with ECMO to cardiac transplant were stratified as group 1 whereas those bridged with ECMO to LVAD were stratified as group 2. The average ECMO run was 3 days in group 1 versus 11 days in group 2. Among group 1 patients, the ICER was $246,629 but was paired with a longer life expectancy. The ICER of group 2 patients was –$107,088 and was not paired with a longer life expectancy. The average inpatient cost for group 1 was found to be $636,023 versus $769,471 for group 2 patients. The average inpatient costs for patients not bridged to ECMO who received cardiac transplant or LVAD was $538,928 and $325,242, respectively.

Conclusions

Using ECMO to bridge to transplant or LVAD placement is not cost effective. However, patients bridged to transplant are paired with longer life expectancy in contrast to patients bridged to LVAD.

Extracorporeal membrane oxygenation as a bridge to durable mechanical circulatory support or heart transplantation

BACKGROUND

Patients with cardiogenic shock may require extracorporeal membrane oxygenation (ECMO) prior to durable mechanical circulatory support (dMCS) or heart transplantation (HTx).

METHODS

We investigated the clinical characteristics and outcomes of adult patients with ECMO support as bridge to dMCS or HTx between 1/1/13 and 12/31/20.

RESULTS

Of 57 patients who underwent bridging ECMO, 41 (72%) received dMCS (approximately half with biventricular support) and 16 (28%) underwent HTx, 13 (81%) after the 2018 UNOS allocation system change. ECMO → HTx patients had shorter ventilatory time (3.5 vs 7.5 days; p = 0.018), ICU stay (6 vs 18 days; p = 0.001), and less need for inpatient rehabilitation (18.8% vs 57.5%; p = 0.016). The 1-year survival post HTx was 81.3% in the ECMO → HTx group and 86.4% in the ECMO → dMCS group (p = 0.11). For those patients in the ECMO → dMCS group who did not undergo HTx, 1-year survival was significantly lower, 31.6% (p = 0.001).

CONCLUSION

Patients on ECMO who undergo HTx, with or without dMCS bridge, have acceptable post-HTx survival. These findings suggest that HTx from ECMO is a viable option for carefully selected patients deemed acceptable to proceed with definitive advanced therapies, especially in the era of the new UNOS allocation system.

Veno-arterial Extracorporeal Membrane Oxygenation as Bridge to Heart Transplantation: The Way Forward

Advanced heart failure (HF) represents a public health priority due to the increase of affected patients and the meaningful mortality. Durable mechanical circulatory support (MCS) and heart transplantation (HTx) are unique therapies for end-stage HF (ESHF), with positive early and long-term outcomes. The patients who underwent HTx have a 1-y survival of 91% and a median survival of 12-13 y, whereas the median survival of ESHF is <12 mo. Short-term MCS with veno-arterial extracorporeal membrane oxygenation (VA ECMO) can be used as a bridge to transplantation strategy. Patients bridged with VA ECMO have significantly lower survival in comparison with non-MCS bridged and left ventricular assist device-bridged patients. VA ECMO represents an effective, and sometimes unique, system to obtain rapid hemodynamic stabilization, but possible negative effects on patients' outcomes after HTx must be considered. Here, we discuss the use of VA ECMO as bridge to transplantation.

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.

Costs Before and After Left Ventricular Assist Device Implant and Preceding Heart Transplant: A Cohort Study

BACKGROUND

Up to 50% of heart transplant candidates require bridging with left ventricular assist devices (VAD). This study describes hospital activity and cost 1 year preceding and 1 year following VAD implant (pre-VAD) and for the year before transplant (pre-HTX). The sample comprises an Australian cohort and is the first study to investigate costs using both institutional and linked administrative data.

METHODS

Institutional activity was established for 77 consecutive patients actively listed for transplant between 2009 and 2012. Costs were sourced from the institution or Australian refined diagnosis groups (arDRGs) and the National Efficient Price for admissions to other public and private institutions. Data from 25/77 VAD recipients were analysed and compared with data from 52/77 pre-transplant patients. Total and per day at risk costs were assessed, as well as totals per resource.

RESULTS

Fifty per cent (50%) of the hospital costs in the pre-VAD year occurred during admission of VAD implant. Sixty-four per cent (64%) of costs in the pre-HTX and 38% in the pre-VAD period occurred outside the implanting centre. Costs in the year prior to VAD, $97,565 (IQR $86,907-$153,916), were significantly higher than costs accrued in the year prior to transplant, $40,250 ($13,493-$81,260), p < 0.0001. Once discharged, costs per day at risk for post-VAD patients approximated those from the pre-admission period, p = 0.16 and in the more clinically stable pre-HTX cohort, p = 0.08.

CONCLUSION

Compared with the year prior, VAD implant stabilised hospital cost in patients discharged home. A high proportion of the hospital costs in the pre-implant year occur outside the implanting centre and should be considered in economic models assessing the impact of VAD implant.

What are the results of venoarterial extracorporeal membrane oxygenation bridging to heart transplantation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether heart transplantation is a viable treatment option in patients in refractory cardiogenic shock who could not be weaned off venoarterial extracorporeal membrane oxygenation (VA ECMO). Altogether, 373 papers were found using the reported search, of which 7 papers represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Evidence is derived from 3 papers based on registry analysis, 1 multi-institutional study and 3 single-institution reviews. Early post-transplant mortality of ECMO-bridged recipients ranges from 18.7% to 33.3% and 1-year survival from 44.6% to 72.0%. High acuity of recipient illness reflected by poor renal function, mechanical ventilation, advanced age, elevated serum lactate predict inferior outcome. We conclude that heart transplantation results in patients bridged with VA ECMO are inferior when compared to published outcome of non-bridged recipients. In the era of severe organ shortage and intense public and regulatory scrutiny of the results, the decision to transplant a patient directly of VA ECMO needs to be made on a case-by-case basis. Potential gain in decreasing the waiting list mortality of these critically ill patients needs to be weighed against poorer post-transplantation mortality rates and mid- and long-term outcomes.

Utilizing the index for mortality prediction after cardiac transplantation risk score to predict hospital resource consumption

OBJECTIVE

The index for mortality prediction after cardiac transplantation (IMPACT) risk score incorporates 12 preoperative recipient-specific variables, and has been validated as an accurate predictor of short- and long-term mortality after orthotopic heart transplantation (OHTx). We believe it can also be used to predict hospital costs, and we hypothesize that higher preoperative IMPACT risk scores are associated with increased hospital resource consumption.

METHODS

All OHTx patients ≥18 years of age at our institution were reviewed from 1 January 2000 to 31 December 2014. Total index hospitalization costs post-transplant were extracted and presented in 2014 consumer price index inflation-adjusted US dollars. Patients were stratified into quartiles (Q) according to IMPACT risk scores. Logarithmic transformation normalized cost data, and linear regression assessed for correlation. A comparison of cost between Q of IMPACT risk score was performed using rank-sum and Kruskal-Wallis tests. Survival was estimated using the Kaplan-Meier method.

RESULTS

Three hundred fifty-six (n = 356) OHTx were performed during the study period. The median IMPACT score for the cohort was five (interquartile range [IQR] 3-6). Eight (2.2%) patients died within 30-days and 1-year Kaplan-Meier survival was 88.3%. The median length of stay (LOS) was 16 (IQR 14-24) days. The median hospital cost for index admission was $222 200 (IQR:$169 200-$313 700). Median LOS was longer in Q4 vs Q1 (18 days vs 15 days, P = .01) and index hospital costs in Q4 were significantly higher compared to Q1 patients ($280 400 vs $205 000, P < .01). There was a significant positive correlation between IMPACT risk score and cost (regression coefficient .04, P < .01).

CONCLUSION

This is the first study in adult cardiac transplantation to identify a positive correlation between hospital cost and recipient risk using the IMPACT risk score. Cost and resource consumption for the index admission after OHTx were significantly higher in the highest IMPACT risk Q compared with patients in the lowest Q.

Cost and Factors Associated With the Hospitalization of Patients Undergoing Heart Transplantation

OBJECTIVES

The aim of the study was to describe the cost and factors associated with the hospitalization of patients undergoing heart transplantation.

METHODS

A cross-sectional, descriptive study with a quantitative approach developed at an important heart transplant center in southern Brazil. Twenty patients who had undergone transplantation during the period 2007 to 2016 were included in the study. Central tendency measures and values presented as mean ± SD or median and quartiles were calculated. Multiple linear regression was performed to verify the variables that interfered with the cost.

RESULTS

The cost of hospitalization of patients undergoing heart transplantation was $522,997.26 in Brazilian reals ($220,002.58 in US dollars). The Brazilian public health system was responsible for paying the hospital bill of all patients. Female sex, patients up to 40 years of age, and length of stay in the hospital units were variables that were related to the highest values for the hospital service. Clinical complications of the patients during the hospitalization period were also factors that were related to the greater length of stay in the hospitalization units, reflecting higher expenses for the health institution.

CONCLUSIONS

There is a need for health managers to implement strategies that will minimize complications, such as health care-related infections, that can be prevented during hospitalization and to stimulate the allocation of resources in order to improve care and reduce hospital expenses.

COMBINING INSTITUTIONAL AND ADMINISTRATIVE DATA TO ASSESS HOSPITAL COSTS FOR PATIENTS RECEIVING VENTRICULAR ASSIST DEVICES

OBJECTIVES

The aim of this study was to describe patient level costing methods and develop a database of healthcare resource use and cost in patients with AHF receiving ventricular assist device (VAD) therapy.

METHODS

Patient level micro-costing was used to identify documented activity in the years preceding and following VAD implantation, and preceding heart transplant for a cohort of seventy-seven consecutive patients listed for heart transplantation (2009-12). Clinician interviews verified activity, established time resource required for each activity, and added additional undocumented activities. Costs were sourced from the general ledger, salary, stock price, pharmacy formulary data, and from national medical benefits and prostheses lists. Linked administrative data analyses of activity external to the implanting institution, used National Weighted Activity Units (NWAU), 2014 efficient price, and admission complexity cost weights and were compared with micro-costed data for the implanting admission.

RESULTS

The database produced includes patient level activity and costs associated with the seventy-seven patients across thirteen resource areas including hospital activity external to the implanting center. The median cost of the implanting admission using linked administrative data was $246,839 (interquartile range [IQR] $246,839-$271,743), versus $270,716 (IQR $211,740-$378,482) for the institutional micro-costing (p = .08).

CONCLUSIONS

Linked administrative data provides a useful alternative for imputing costs external to the implanting center, and combined with institutional data can illuminate both the pathways to transplant referral and the hospital activity generated by patients experiencing the terminal phases of heart failure in the year before transplant, cf-VAD implant, or death.

Heart transplantation versus left ventricular assist devices as destination therapy or bridge to transplantation for 1-year mortality: a systematic review and meta-analysis

Background

The optimal treatment for advanced heart failure (HF) patients with regards to mortality remains unknown. Heart transplantation (HTx) and left ventricular assist devices (LVAD) used either as a bridge to transplant (BTT) or destination therapy (DT) have been compared in a number of studies, without definite conclusions with regards to mortality benefit. We sought to systematically review the pertinent literature and perform a meta-analysis of all the available studies presenting head-to-head comparisons between HTx and LVAD BTT or LVAD DT for late (>6 months) all-cause mortality.

Methods

We performed a systematic search of Medline and Cochrane Central databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a meta-analysis of late mortality comparing HTx vs. BTT LVAD and HTx vs. DT LVAD using a random effects model.

Results

Eight studies were included in our meta-analysis, reporting data on 7,957 patients in total. Although the available studies are of high quality [8 stars in Newcastle-Ottawa Scale (NOS) on average], there is paucity of mortality data. Specifically, seven studies compared HTx with BTT and five studies compared HTx with DT for 1-year mortality. Our pooled estimates showed that there was no difference in late mortality among these strategies.

Conclusions

Our meta-analysis highlights the small number and the heterogeneity of available studies referring to the optimal invasive management of advanced HF, and shows that there are no differences between HTx and LVAD for these patients with regards to late mortality.