Improved Survival After Heart Transplantation in Patients With Bridge to Transplant in the Recent Era: A 17-year Single-center Experience

Body mass Index does not impact long-term survival of patients with idiopathic pulmonary fibrosis undergoing lung transplantation

Objective

We investigated the impact of body mass index (BMI) on post-operative outcomes and survival of patients with interstitial pulmonary fibrosis (IPF) undergoing lung transplantation.

Methods

We retrospectively reviewed 222 patients with IPF that underwent lung transplant (LT) at our institution from 2005 to 2019. Recipients were divided in 4 groups: group-1 consisted of underweight patients (BMI ≤18.5 kg/m2), group-2 of normal weight patients (BMI 18.5-25 kg/m2), group-3 of over-weight patients (BMI 25-29.9 kg/m2) and group-4 of obese patients (BMI ≥30 kg/m2).

Results

Group-1 consisted of 13 (6%) patients, group-2 of 67 (30%) patients, group-3 of 79 (36%) patients, group-4 consisted of 63 (28%) patients. Median BMI for group-1 was 17 [interquartile range (IQR): 17, 18], for group-2 was 23 (22, 24), for group-3 was 29 (28, 29.5) and group-4 was 32 (31, 33). Patients in group-1 were significantly younger (p < 0.01). Single LT comprised the majority of operation type in group-2 to group-4 and it was significantly higher than group 1 (p < 0.01). Median follow-up time was 39 months (13-76). A total of 79 (35.5%) patients died by the end of study. Overall, five deaths occurred in group-1, 17 in group-2, 33 in group-3, and 24 in group-4. Kaplan-Meier analysis showed that mortality was not statistically significant between the groups (p = 0.24). Cox-regression analysis was used to assess other possible risk factors that could influence the effect of BMI on mortality, including transplant type (single, double), lung allocation score, and age, diabetes and creatinine levels at surgery. None of these factors were shown to affect patient mortality (p > 0.05). Overall reasons for death included graft failure (24%), infection (23%), respiratory failure (14%), and malignancy (13%).

Conclusions

Body mass index does not impact long-term survival of patients with IPF undergoing lung transplantation.

Thirty-Year Trends in Graft Survival After Heart Transplant: Modeled Analyses of a Transplant Registry

BACKGROUND

Heart failure is an epidemic in the United States, and transplantation remains the most definitive therapy. We describe multidecade trends in posttransplant graft survival, adjusted for concurrent changes in the population, over the 30 years antecedent to the most recent heart allocation policy change.

METHODS

Scientific Registry of Transplant Recipients data were used to identify all primary adult heart recipients from 1989 to 2017. We described temporal changes in population characteristics (recipient and donor demographics and comorbidities, pretransplant interventions, clinical transplant measures, and providers). The primary outcome was graft survival, defined as freedom from all-cause death and graft failure, within 6 months posttransplant. Modified Poisson logistic regression estimated relative changes in risk of outcomes compared with 1989, with and without adjustment for changing population characteristics. We identified risk factors, quantified by associated risk ratios.

RESULTS

Among 56,488 primary adult heart recipients, we observed 5529 (9.8%) all-cause deaths and 1933 (3.4%) graft failure events within 6 months posttransplant. Prevalence of known recipient risk factors increased over time. Unadjusted modeling demonstrated a significant 30-year improvement in graft survival, averaging 2.6% per year (95% confidence interval, 2.4-2.9; P for trend < .001). After adjusting for population changes the 30-year trend remained significant and graft survival improved on average 3.0% per year (95% confidence interval, 2.6-3.3). Regression modeling identified multiple predictors of graft survival. Modeling 2 additional outcomes of 6-month mortality and 6-month graft failure produced similar results.

CONCLUSIONS

Short-term graft survival after heart transplantation has improved significantly leading up to the 2018 heart allocation policy change, despite concurrent increase in prevalence of higher risk population characteristics.

Ventricular assist devices and middle age reduce heart transplantation rates for waitlist candidates

BACKGROUND

Ventricular assist devices (VADs) are commonly employed as a bridge to transplantation for heart failure. The full effects of VADs on transplantation rates are not fully understood. We sought to compare transplantation rates stratified by age and VAD status.

METHODS

Using the Organ Procurement and Transplantation Network (OPTN) database, we investigated the impact of age and VAD status on heart allocation rates among all transplant-eligible patients from January 2005 to September 2018. Patients were grouped based on the presence (+) or absence (-) of a VAD as well as age (<45, 45-65, and >65 years). Demographics were compared with a multivariate competing risk analysis that yielded risk-adjusted subdistribution hazard ratios (SHR).

RESULTS

Among the 50 602 total waitlist candidates, 18 271 patients with a VAD had higher rates of diabetes and cerebrovascular disease at waitlist entry. Multivariate analysis found statistically significant lower rates of transplantation for all (+)VAD groups compared with age-matched (-)VAD counterparts, with the 45- to 65-year-old (+)VAD group having the lowest transplantation rate (SHR = 0.62; P < .0005). Among (-)VAD patients, transplantation rates increased with increase in age.

CONCLUSIONS

There is a statistically significant reduced rate of transplantation for patients with a VAD compared with those without a VAD, with the lowest rate among those of ages 45 to 65 years with a VAD. The increasing prevalence of this demographic and the deprioritization of VADs in the new heart allocation criteria have the potential to further exacerbate this difference.

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.

New role of ventricular assist devices as bridge to transplantation: European perspective

PURPOSE OF REVIEW

Progress of ventricular assist devices (VAD) technology led to improved survival and apparently low morbidity. However, from the European perspective, updated analysis of EUROMACS reveals a somewhat less impressive picture with respect to mortality and morbidity.

RECENT FINDINGS

We describe the great demand of cardiac allografts versus the lack of donors, which is larger in Europe than in the United States. Technical progress of VADs made it possible to work out a modern algorithm of bridge-to-transplant, which is tailored to the need of the particular patient. We analyze the burden of patients undergoing bridge-to-transplant therapy. They are condemned to an intermediate step, coupled with additional major surgery and potential adverse events during heart transplantation.

SUMMARY

Based on current registry data, we do have to question the increasingly popular opinion, that the concept of heart transplantation is futureless, which seems to be for someone who treats and compares both patients (VAD and heart transplantation) in daily practice, questionable. Up to now, left ventricular assist device therapy remains a bridge to a better future, which means a bridge to technical innovations or to overcome the dramatic lack of donors in Europe.

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.

Medium-term outcome of recipients of marginal donor hearts selected with new stress-echocardiographic techniques over standard criteria

BACKGROUND

Heart transplantation is limited by severe donor organ shortage. Regardless of the changes made in the acceptance of marginal donors, any such mechanism cannot be considered successful unless recipient graft survival rates remain acceptable. A stress echo-driven selection of donors has proven successful in older donors with normal left ventricular resting function and in standard donors with reversible resting left ventricular dysfunction acutely improving during stress, or slowly improving (over hours) during intensive hormonal treatment. Aim of this study is to assess the medium-term outcome of recipients of marginal donor hearts selected with new echocardiographic techniques over standard criteria.

METHODS AND RESULTS

We enrolled 43 recipients of marginal donor hearts: age > 55 years, or < 55 years but with concomitant risk factors, n = 32; acutely improving during stress, n = 3; or slowly improving during hormonal treatment, n = 8. At follow-up (median, 30 months; interquartile range, 21-52 months), 37 of the recipients were still alive. One-year survival was 93%.

CONCLUSION

The strict use of new stress-echocardiographic techniques over standard criteria of marginal donor management, together with comprehensive monitoring of the donor, has the potential to substantially increase the number of donor hearts without adverse effects on recipient medium-term outcome.

Regional differences in recipient waitlist time and pre- and post-transplant mortality after the 2006 United Network for Organ Sharing policy changes in the donor heart allocation algorithm

OBJECTIVES

This study examined the impact of the United Network for Organ Sharing (UNOS) policy changes for regional differences in waitlist time and mortality before and after heart transplantation.

BACKGROUND

The 2006 UNOS thoracic organ allocation policy change was implemented to allow for greater regional sharing of organs for heart transplantation.

METHODS

We analyzed 36,789 patients who were listed for heart transplantation from January 1999 through April 2012. These patients were separated into 2 eras centered on the July 12, 2006 UNOS policy change. Pre- and post-transplantation characteristics were compared by UNOS regions.

RESULTS

Waitlist mortality decreased nationally (up to 180 days: 13.3% vs. 7.9% after the UNOS policy change, p < 0.001) and within each region. Similarly, 2-year post-transplant mortality decreased nationally (2-year mortality: 17.3% vs. 14.6%; p < 0.001) as well as regionally. Waitlist time for UNOS status 1A and 1B candidates increased nationally 17.8 days on average (p < 0.001) with variability between the regions. The greatest increases were in Region 9 (59.2-day increase, p < 0.001) and Region 4 (41.2-day increase, p < 0.001). Although the use of mechanical circulatory support increased nearly 2.3-fold nationally in Era 2, significant differences were present on a regional basis. In Regions 6, 7, and 10, nearly 40% of those transplanted required left ventricular assist device bridging, whereas only 19.6%, 22.3%, and 15.5% required a left ventricular assist device in regions 3, 4, and 5, respectively.

CONCLUSIONS

The 2006 UNOS policy change has resulted in significant regional heterogeneity with respect to waitlist time and reliance on mechanical circulatory support as a bridge to transplantation, although overall both waitlist mortality and post-transplant survival are improved.

Impact of long term left ventricular assist device therapy on donor allocation in cardiac transplantation

BACKGROUND

Left Ventricular Assist Devices (LVAD) are increasingly used as a bridge to transplant (BTT) for patients with advanced congestive heart failure (CHF) and are assigned United Network for Organ Sharing (UNOS) high priority status (1B or 1A).

METHODS

The purpose of our study was asses the effect of organ allocation in the era of continuous flow pumps. A retrospective chart review was performed of all patients transplanted between 1/2001-1/2011 at Columbia University Medical Center.

RESULTS

Seven hundred twenty six adult heart transplantations were performed. Two hundred seventy four BTT patients were implanted with LVAD; of which 227 patients were transplanted. Sixty three patients were transplanted as UNOS-1B, while 164 were transplanted as UNOS-1A (72%). Of these 164 patients, 65 were transplanted during their 30-day 1A period (43%) and 96 after upgrading to UNOS-1A for device complication (56%). For 452 non-device patients 139 (31%) were transplanted as UNOS-1A, 233 as UNOS-1B (52%), and 80 as UNOS-2 (17%). The percentage of patients bridged with LVAD increased from 19% in 2001 to 64% in 2010 while the number transplanted during their 30 day 1A grace period declined from 57% in 2005 to 16% in 2011; i.e. 84% of BTT patients in 2011 needed more than 30 days 1A time to be transplanted. Most LVAD patients are now transplanted while suffering device complication. There was no difference in post transplant survival between LVAD patients transplanted as UNOS 1B, 1A grace period or for a device complication

CONCLUSIONS

As wait time for cardiac transplantation increased the percentage of patients being bridged to transplant with an LVAD has increased with the majority of them transplanted in the setting of device complication.

Should patients 60 years and older undergo bridge to transplantation with continuous-flow left ventricular assist devices?

BACKGROUND

Although left ventricular assist devices (LVADs) are now commonly used as a bridge to orthotopic heart transplantation (OHT), the upper patient age limit for this therapy has not been defined. Smaller studies have suggested that advanced age should not be a contraindication to bridge to transplantation (BTT) LVAD placement. The purpose of this study was to examine outcomes in patients 60 years and older undergoing BTT with continuous-flow LVADs.

METHODS

The United Network for Organ Sharing (UNOS) database was reviewed to identify first-time OHT recipients 60 years of age and older (2005-2010). Patients were stratified by preoperative support: continuous-flow LVAD, intravenous inotropic agents, and direct transplantation. Survival after OHT was modeled using the Kaplan-Meier method. All-cause mortality was examined using multivariable Cox proportional hazard regression.

RESULTS

Of 2,554 patients, 1,142 (44.7%) underwent direct transplantation, 264 (10.3%) had LVAD BTT, and 1,148 (45.0%) had BTT with inotropic agents. The mean age was 64±3 years, and 460 (18.0%) patients were women. Mean follow-up was 29±19 months. Survival differed significantly among the 3 groups. Patients with LVAD BTT had significantly lower survival after OHT compared with the other groups at 30 days and 1 year. This survival difference was no longer significant at 2 years after OHT or when deaths in the first 30 days were censored. LVAD BTT increased the hazard of death at 1 year by 50% (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.05-2.15; p=0.03), compared with patients who underwent direct transplantation.

CONCLUSIONS

This study represents the largest modern cohort in which survival after OHT has been evaluated in patients 60 years or older who received BTT. Older patients have lower short-term survival after OHT when BTT is carried out with a continuous-flow LVAD compared with inotropic agents or direct transplantation.

The pharmacotherapy implications of ventricular assist device in the patient with end-stage heart failure

Advances in mechanical circulatory support, such as the use of ventricular assist devices (VADs), have become a means for prolonging survival in end-stage heart failure (HF). VADs decrease the symptoms of HF and improve quality of life by replacing some of the work of a failing heart. They unload the ventricle to provide improved cardiac output and end-organ perfusion, resulting in improvement in cardiorenal syndromes and New York Heart Association functional class rating. VADs are currently used asa bridge to heart transplantation, a bridge to recovery of cardiac function, or as destination therapy. Complications of VAD include bleeding, infections, arrhythmias, multiple organ failure, right ventricular failure, and neurological dysfunction. Patients with VAD have unique pharmacotherapeutic requirements in terms of anticoagulation, appropriate antibiotic selection, and continuation of HF medications. Pharmacists in acute care and community settings are well prepared to care for the patient with VAD. These patients require thorough counseling and follow-up with regard to prevention and treatment of infections, appropriate levels of anticoagulation, and maintenance of fluid balance. A basic understanding of this unique therapy can assist pharmacists in attending to the needs of patients with VAD.

Effective ventricular unloading by left ventricular assist device varies with stage of heart failure: cardiac simulator study

Although the use of left ventricular assist devices (LVADs) as a bridge-to-recovery (BTR) has shown promise, clinical success has been limited due to the lack of understanding the timing of implantation, acute/chronic device setting, and explantation. This study investigated the effective ventricular unloading at different heart conditions by using a mock circulatory system (MCS) to provide a tool for pump parameter adjustments. We tested the hypothesis that effective unloading by LVAD at a given speed varies with the stage of heart failure. By using a MCS, systematic depression of cardiac performance was obtained. Five different stages of heart failure from control were achieved by adjusting the pneumatic systolic/diastolic pressure, filling pressure, and systemic resistance. The Heart Mate II® (Thoratec Corp., Pleasanton, CA) was used for volumetric and pressure unloading at different heart conditions over a given LVAD speed. The effective unloading at a given LVAD speed was greater in more depressed heart condition. The rate of unloading over LVAD speed was also greater in more depressed heart condition. In conclusion, to get continuous and optimal cardiac recovery, timely increase in LVAD speed over a period of support is needed while avoiding the akinesis of aortic valve.

Favorable short-term outcome of transplanted hearts selected from marginal donors by pharmacological stress echocardiography

BACKGROUND

Because of the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Abnormal results on pharmacologic stress echocardiography are associated with significant coronary artery disease and/or occult cardiomyopathy on verification by cardiac autopsy. The aim of this study was to establish the feasibility of an approach based on pharmacologic stress echocardiography as a gatekeeper for extended heart donor criteria.

METHODS

From April 2005 to April 2010, 39 "marginal" candidate donors (mean age, 56 ± 6 years; 21 men) were initially enrolled. After legal declaration of brain death, marginal donors underwent rest echocardiography, and if the results were normal, dipyridamole (0.84 mg/kg over 6 min, n = 25) or dobutamine (up to 40 μg/kg/min, n = 3) stress echocardiography.

RESULTS

A total of 19 eligible hearts were found with normal findings. Of these, three were not transplanted because of the lack of a matching recipient, and verification by cardiac autopsy showed absence of significant coronary artery disease or cardiomyopathy abnormalities. The remaining 16 eligible hearts were uneventfully transplanted in marginal emergency recipients. All showed normal (n = 14) or nearly normal (minor single-vessel disease in two) angiographic, intravascular ultrasound, hemodynamic and ventriculographic findings at 1 month. At follow-up (median, 14 months; interquartile range, 4-31 months), 14 patients survived and two had died, one at 2 months from general sepsis and one at 32 months from allograft vasculopathy in recurrent multiple myeloma.

CONCLUSIONS

Pharmacologic stress echocardiography can safely be performed in candidate heart donors with brain death and shows potential for extending donor criteria in heart transplantation.

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

A best evidence topic in cardiac surgery was written according to a structured protocol. The issue was to determine the impact of bridge-to-transplant ventricular assist device support on survival after cardiac transplantation. Altogether 428 papers were found using the reported search, of which 12 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. The treatment options for patients with advanced heart failure or those with deteriorating end-organ function on maximal medical therapy are limited to intravenous inotropes and mechanical assistance with intra-aortic balloon pump (IABP) or ventricular assist device (VAD). Studies exploring the effect of VADs on post-transplant mortality have yielded conflicting results. The Registry of the International Society for Heart and Lung Transplantation continues to identify mechanical support as a risk factor for decreased survival after transplantation. A limitation of this report is that the multivariable adjustment uses variables recorded not at the time of device implant but at the time of transplant. Some of the recipient characteristics thus may be altered by the device implant. Compared with the previous reports the latest data show improvement in post-transplant survival in the recent era. In addition, the excess risk appears to be limited to the early post-transplant period. Experienced centers consistently report outstanding post-transplant results with left ventricular assist device (LVAD) bridging. Of the 12 papers seven showed no difference in survival, and five showed a reduced survival. In the papers showing no difference, one year survival averaged from 85% in supported patients to 87% in non-supported patients. In papers reporting a difference in outcome, one year averaged survival was 74% in LVAD recipients compared to 90% in non-bridged patients. Decreased survival is associated with patients suffering from dilated cardiomyopathy, transplanted within two weeks of LVAD implantation and bridged to transplantation before 2003 as opposed to patients transplanted more recently. Based on the available evidence we conclude that in selected patients survival after heart transplantation in patients bridged with VAD is comparable to those who did not receive the device.

Heart transplantation in the United States, 1999-2008

This article features 1999-2008 trends in heart transplantation, as seen in data from the Organ Procurement and Transplantation Network (OPTN) and the Scientific Registry of Transplant Recipients (SRTR). Despite a 32% decline in actively listed candidates over the decade, there was a 20% increase from 2007 to 2008. There continues to be an increase in listed candidates diagnosed with congenital heart disease or retransplantation. The proportion of patients listed as Status 1A and 1B continues to increase, with a decrease in Status 2 listings. Waiting list mortality decreased from 2000 through 2007, but increased 18% from 2007 to 2008; despite the increase in waiting list death rates in 2008, waiting list mortality for Status 1A and Status 1B continues to decrease. Recipient numbers have varied by 10% over the past decade, with an increased proportion of transplants performed in infants and patients above 65 years of age. Despite the increase in Status 1A and Status 1B recipients at transplant, posttransplant survival has continued to improve. With the rise in infant candidates for transplantation and their high waiting list mortality, better means of supporting infants in need of transplant and allocation of organs to infant candidates is clearly needed.

[Pulmonary hypertension and heart failure: the role of pulmonary vasculature]

Left heart disease is the most common cause of pulmonary hypertension. Increased left-sided filling pressure leads to passive postcapillary venous hypertension. In some patients, pulmonary vasoconstriction and vascular remodeling may lead to a further increase in pulmonary pressure. When precapillary hypertension component is associated to left heart failure, the elevation of pulmonary pressure is out of proportion with left atrial pressure: transpulmonary gradient greater than 12 mmHg (mean pulmonary pressure -- mean capillary pressure) and pulmonary vascular resistance greater than three Wood units. Precapillary pulmonary hypertension is common in severe systolic heart failure. Before cardiac transplantation, increased pulmonary vascular resistance greater than 3,5 Wood units are reported in 19 to 35% of patients. In those patients vasoreactivity tests are performed with inotropic and/or systemic and/or pulmonary agents to determine the risk of right heart failure after transplantation. There is no pulmonary vascular resistance level above which transplantation is contraindicated. Cardiac assistance may be used before and after transplantation when pulmonary hypertension is severe and not reversible with conventional treatment and/or pulmonary vasodilators. The contribution of precapillary PH in diastolic heart failure is not known but can be significant and lead to disproportionate PH particularly in elderly. The precapillary component of pulmonary hypertension could be a therapeutic target for specific pulmonary vasodilators. Until now pharmacological trials has been disappointing and those medications can be dangerous because of increasing blood flow to the pulmonary capillaries with a risk of pulmonary edema when left sided pressure are still elevated.