Impact of Ventricular Assist Device Complications on Posttransplant Survival: An Analysis of the United Network of Organ Sharing Database

Impact of Heart Transplant Allocation Change on Waitlist Mortality and Posttransplant Mortality in Patients With Left Ventricular Assist Devices

BACKGROUND

In October 2018, the US heart transplant (HT) allocation system was revised giving patients with left ventricular assist device (LVAD) intermediate priority status. Few studies have examined the impact of this policy change on outcomes among patients with LVAD. We sought to determine how the allocation change impacted waitlist and posttransplant mortality in patients with LVAD.

METHODS

We retrospectively assessed the United Network for Organ Sharing registry for patients with LVAD who were listed for or underwent HT between October 2016 and October 2021. We evaluated waitlist mortality using competing risks analysis and a multivariable Fine-Gray model, and posttransplant mortality using Kaplan-Meier survival analysis and a multivariate proportional hazards model.

RESULTS

We analyzed data from 3835 patients with LVAD listed for HT and 3486 patients with LVAD who underwent HT during the study period. Listing for HT preallocation change was significantly associated with an increased risk of waitlist mortality (Gray P=0.0058) compared with postallocation change. After adjustment for covariates, mortality differences by listing era were attenuated, but LVAD brand was significantly associated with waitlist mortality (HM3 versus HMII; hazard ratio, 0.38 [95% CI, 0.21-0.69]; P=0.002; HVAD versus HMII; hazard ratio, 0.79 [95% CI, 0.48-1.30]; P=0.36; overall P=0.004). In contrast, HT postallocation change was associated with increased posttransplant mortality (log-rank P=0.0172) compared with preallocation change. In a multivariable analysis, the association with posttransplant mortality between transplant eras was attenuated, but ischemic time (hazard ratio, 1.16 [95% CI, 1.07-1.26]; P<0.001) and status at time of HT (Status 1-3 versus 4; hazard ratio, 1.29 [95% CI, 1.04-1.61]; P=0.02) were significantly associated with posttransplant mortality.

CONCLUSIONS

Among patients with LVAD, lower waitlist mortality postallocation change was likely driven by improved LVAD technology. Higher posttransplant mortality following the allocation change was largely attributable to longer ischemic times and patient acuity.

Pre-operative risk factors for driveline infection in left ventricular-assist device patients

AIMS

Implantation of left ventricular-assist devices (LVAD) to treat end-stage heart failure is of increasing relevance due to donor shortage. Infections of the driveline are common adverse events. LVAD infections can lead to high urgency listings for transplantation. However, transplantation in patients with infection leads to worse post-transplantation outcomes. This study aims to evaluate specific risk factors for driveline infections at the time of implantation.

METHODS AND RESULTS

Four hundred forty-one patients receiving either Heartmate II or Heartware system from August 2009 to October 2013 were assessed. An expert committee sorted patients into four different groups concerning the likeliness of infection. Twenty-eight (6%) of discussed infection cases were judged as secured, 33 (7%) as likely, 18 (4%) as possible, and 20 (4%) as unlikely. The remaining 342 (78%) subjects showed either no signs of infection at all times (329 [75%]) or developed signs of infection in a second observation period within 1 year after ending of the first observation period (13 [3%]). For a better discriminatory power, cases of secured and likely infections were tested against the group with no infection at all times in a Cox proportional hazard model. Among all variables tested by univariate analysis (significance level P < 0.15), only age (P = 0.07), LVAD-type (P = 0.12), need for another thoracic operation (P = 0.02), and serum creatinine value (P = 0.02) reached statistical significance. These were subsequently subjected to multivariate analysis to calculate the cumulative risk of developing a drive infection. The multivariate analysis showed that of all the potential risk factors tested, only the necessity of re-thoracotomy or secondary thoracic closure had a significant, protective effect (hazard ratio [95% CI] = 0.45 [0.21-0.95]; P = 0.04).

CONCLUSION

This single-centre cohort study shows that driveline infections are common adverse events. The duration of support represents the major risk factor for LVAD driveline infections.

Relation of Left Ventricular Assist Device Infections With Cardiac Transplant Outcomes

Left ventricular assist device (LVAD)-specific infections (LSIs) are common in patients on LVAD support awaiting heart transplant (HT), yet their impact on post-HT outcomes is not completely understood. We hypothesized that LSIs would result in vasoplegia and negatively affect post-HT 30-day and 1-year outcomes. LSI was defined as driveline, pump, or pocket infection. The short-term outcome was a composite of acute renal failure, allograft rejection, and mortality at 30 days after HT. The long-term outcome was a composite of allograft rejection and death within 1 year after HT. We performed a retrospective analysis of 111 HT recipients bridged with durable LVAD support at our institution from May 2012 to August 2019. Of these, 63 patients had LSIs, with 94% of the infections being driveline infections. Vasoplegia was more prevalent in the LSI group but not significantly (7 vs 2 persons, p = 0.3). There was no difference in the composite end point of acute renal failure, rejection, or death at 30 days (30% vs 25%, p = 0.55) or 1-year end point of rejection and death (38% vs 40%, p = 0.87) in patients with LSI versus those without LSI. In conclusion, LSIs were common in patients on LVAD who underwent HT in our single-center contemporary cohort. However, LSI was not associated with adverse outcomes at 30 days or at 1 year after HT.

Posttransplant Long-Term Outcomes for Patients with Ventricular Assist Devices on the Heart Transplant Waitlist

Ventricular assist devices (LVADs) are commonly used in end-stage heart failure for mechanical circulatory support as a bridge to heart transplantation. However, LVADs' long-term effects on posttransplant survival are unknown. We sought to compare long-term mortality after transplantation for patients with and without LVADs. Using the Organ Procurement and Transplantation Network database, we investigated LVADs' impact on long-term (3 month, 1 year, 2 years, 5 years, and 8 years) posttransplant mortality risk for all heart transplant recipients between 2010 and 2019. Time-to-event regression analysis quantified mortality risk by LVAD status in both unconditional and conditional survival analyses. Of 20,113 transplant recipients, 8,999 (45%) had a LVAD while on the waitlist. Among those who died after transplantation, patients with LVADs on average died sooner (1.8 years) than patients without LVADs (3.0 years; p < 0.01). On multivariable analysis, patients with LVADs had a 44% higher mortality risk within the first 3 months posttransplant (HR = 1.44, p = 0.03). There was no significant difference in mortality risk between patients who did and did not have pretransplant LVADs after 1, 2, and 5 years of posttransplant conditional survival. While LVAD patients have a survival disadvantage in the first year posttransplant, conditional survival analysis demonstrated no difference in mortality risk between patients with and without LVADs beyond 1 year of follow up. Of the patients who died posttransplant, patients with LVADs on average died sooner than patients without LVADs.

Impact of Ventricular Assist Device-Specific Infections on Post-Heart Transplant Infections: A Retrospective Single-Center Study

BACKGROUND

Patients with a ventricular assist device (VAD) who are awaiting heart transplant (HTx) are susceptible to infections. Such infections, especially at the site of the VAD, may increase the risk of severe post-transplant infections and mortality. Information on the characteristics of VAD-specific infections and outcomes in HTx recipients after prolonged periods of LVAD therapy is scarce.

PURPOSE

We aimed to assess the impact of active VAD-specific infections on the incidence of early post-transplant infections and patient survival.

METHODS

We conducted a retrospective review of adult HTx cases at our center between April 2011 and October 2020. Informed consent was waived due to study design. A total of 86 patients were included in this study, among whom 94.2% (n = 81) were bridged with a VAD, and the median VAD support period was 1089 days.

RESULTS

Patients with active VAD-specific infections were significantly more likely to develop severe acute mediastinitis [odds ratio (OR) 14.8, 95% confidence interval (CI) 4.83-45.4, P < .01]. Active VAD infections were significantly related to increased length of intensive care unit stay (22.1 days vs 13.0 days, P = .016) and longer mechanical ventilation periods (324.7 hours vs 113.2 hours, P = .03). The 30-day survival rates for patients with and without post-transplant infections were 100% and 97.1%, respectively.

CONCLUSION

Compared to other risk factors, the presence of active VAD-specific infections increases the risk of early post-heart transplant infections and morbidity, without affecting mortality.

Association between continuous-flow left ventricular assist device infections requiring long-term antibiotic use and post-heart transplant morbidity and mortality

BACKGROUND AND AIM OF STUDY

There exists controversy regarding the impact of infection in patients with a left ventricular assist device (LVAD) on post-heart transplant outcomes. This study evaluated the association between infections during LVAD support and the risk of early and late post-heart transplant infection, rejection, and mortality in transplant recipients bridged with an LVAD.

METHODS

This is a single-center retrospective observational cohort study of consecutive adults supported with a continuous flow LVAD undergoing heart transplant between 2006 and 2019 at the Toronto General Hospital. The grade of LVAD infection was classified as per International Society of Heart and Lung Transplantation guidelines. Patients were divided into three groups: (1) patients with LVAD-specific infection confirmed with positive cultures requiring long-term antibiotic use until the time of transplant; (2) patients with any type of infection in whom antibiotics were stopped at least 1 month before transplant; (3) patients without any infections between LVAD implant and transplant. Logistic regression and Cox proportional hazard models were used to evaluate early- and late-post transplant outcomes, respectively.

RESULTS

We included 75 LVAD recipients: 16 (21%) patients had a chronic LVAD-related infection on suppressive antibiotics, 30 (40%) had a resolved infection, and 29 (39%) had no infections. During a median post-transplant follow-up time of 4 (2 to 7) years, 65 (87%) patients developed infections, 43 (64%) rejections, and 17 (23%) deaths. Both short- and long-term risks of infection, rejection, and mortality did not differ significantly among the groups.

CONCLUSION

LVAD patients with infections did not have a significantly higher risk of infection, rejection, or mortality at any time point after transplant.

Contemporary Management Strategies in VAD Infection

PURPOSE OF REVIEW

The use of durable ventricular assist devices (VAD) to manage end-stage heart failure is increasing, but infection remains a leading cause of morbidity and mortality among patients with VAD. In this review, we synthesize recent data pertaining to the epidemiology, diagnosis, management, and prevention of VAD infections, discuss transplant considerations in patients with VAD infections, and highlight remaining knowledge gaps. We also present a conceptual framework for treating clinicians to approach these infections that draws on the same principles that guide the treatment of analogous infections that occur in patients without VAD.

RECENT FINDINGS

Despite advances in device design, surgical techniques, and preventative interventions, more than a third of VAD recipients still experience infection as an adverse outcome. Positron emission tomography has emerged as a promising modality for identifying and characterizing VAD infections. High-quality data to support many of the routine therapeutic strategies currently used for VAD infections-including suppressive antibiotic therapy, surgical debridement/device exchange, and novel antimicrobials for emerging multidrug-resistant organisms-remain limited. Although pre-transplant VAD infection may impact some early transplant outcomes, transplantation remains a viable option for patients with most types of VAD infection. Standardized definitions of VAD infection applied to large registry datasets have yielded key insights into the epidemiology of infectious complications among VAD recipients, but more prospective studies are needed to evaluate the effectiveness of existing and novel diagnostic and therapeutic strategies.

Complications of left ventricular assist devices causing high urgency status on waiting list: impact on outcome after heart transplantation

Aims

Heart transplantation (HTx) represents optimal care for advanced heart failure. Left ventricular assist devices (LVADs) are often needed as a bridge‐to‐transplant (BTT) therapy to support patients during the wait for a donor organ. Prolonged support increases the risk for LVAD complications that may affect the outcome after HTx.

Methods and results

A total of 342 patients undergoing HTx after LVAD as BTT in a 10‐year period in two German high‐volume HTx centres were retrospectively analysed. While 73 patients were transplanted without LVAD complications and with regular waiting list status (T, n = 73), the remaining 269 patients were transplanted with high urgency status (HU) and further divided with regard to the observed leading LVAD complications (infection: HU1, n = 91; thrombosis: HU2, n = 32; stroke: HU3, n = 38; right heart failure: HU4, n = 41; arrhythmia: HU5, n = 23; bleeding: HU6, n = 18; device malfunction: HU7, n = 26). Postoperative hospitalization was prolonged in patients with LVAD complications. Analyses of perioperative morbidity revealed no differences regarding primary graft dysfunction, renal failure, and neurological events except postoperative infections. Short‐term survival, as well as Kaplan–Meier survival analysis, indicated comparable results between the different study groups without disadvantages for patients with LVAD complications.

Conclusions

Left ventricular assist device therapy can impair the outcome after HTx. However, the occurrence of LVAD complications may not impact on outcome after HTx. Thus, we cannot support the prioritization or discrimination of HTx candidates according to distinct mechanical circulatory support‐associated complications. Future allocation strategies have to respect that device‐related complications may define urgency but do not impact on the outcome after HTx.

An Analysis of Waitlist Inactivity Among Patients With Ventricular Assist Devices

BACKGROUND

Ventricular assist devices (VADs) are commonly used mechanical circulatory support for bridge to transplant therapy in end-stage heart failure; however, it is not understood how VADs influence incidence of waitlist inactive status. We sought to characterize and compare waitlist inactivity among patients with and without VADs.

METHODS

Using the Organ Procurement and Transplantation Network database, we investigated the VAD's impact on incidence and length of inactive periods for heart transplant candidates from 2005 through 2018. We compared median length of inactivity between patients with and without VADs and investigated inactivity risk with time-to-event regression models.

RESULTS

Among 46,441 heart transplant candidates, 32% (n = 14,636) had a VAD. Thirty-eight percent (n = 17,873) of all patients experienced inactivity, of which 42% (7538/17,873) had a VAD. Median inactivity length was 31 d for patients without VADs and 62 d for VAD patients (P < 0.0005). Multivariable analysis showed no significant difference in risk of inactivity for deteriorating conditions between patients with and without VADs after controlling for demographic and baseline clinical variables. A larger proportion of patients without VADs were inactive for deteriorating conditions than VAD patients (54%, n = 8242/15,221 versus 32%, n = 3583/11,086, P < 0.001). Ten percent (1155/11,086) of VAD patients' inactive periods were for VAD-related complications.

CONCLUSIONS

Although VAD patients were inactive longer and had an overall increased risk of any-cause inactivity, their risk of inactivity for deteriorating condition was not significantly different from patients without VADs. Furthermore, VAD patients had a smaller proportion of inactivity periods due to deteriorating conditions. Thus, VADs are protective from morbidity for waitlist patients.

The Impact of Left Ventricular Assist Device Infections on Postcardiac Transplant Outcomes: A Systematic Review and Meta-Analysis

Left ventricular assist devices (LVADs) are associated with numerous short- and long-term complications, including infection. The impact LVAD infections have on clinical outcomes after transplantation is not well established. We sought to determine whether the presence of infection while on LVAD support negatively influences outcomes after cardiac transplantation. We searched electronic databases and bibliographies for full text studies that identified LVAD infections during support and also reported on posttransplant outcomes. A meta-analysis of posttransplant survival was conducted using a random effects model. Of 2,373 records, 13 bridge to transplant (BTT) cohort studies were selected (n = 6,631, 82% male, mean age 50.7 ± 2.7 years). A total of 6,067 records (91.5%) received transplant. There were 3,718 (56.1%) continuous-flow LVADs (CF-LVADs), 1,752 (26.4%) pulsatile LVADs, and 1,161 (17.5%) unknown type records. A total of 2,586 records (39.0%) developed LVAD infections. Patients with LVAD infections were younger (50.5 ± 1.5 vs. 51.3 ± 1.5, p = 0.02), had higher body mass indeices (BMIs) (28.4 ± 0.7 vs. 26.8 ± 0.4, p < 0.01), and longer LVAD support times (347.0 ± 157.6 days vs. 180.2 ± 106.0 days, p < 0.01). Meta-analysis demonstrated increased posttransplant mortality in those patients who had an LVAD infection (hazard ratio [HR] 1.30, 95% CI: 1.16-1.46, p < 0.001). Subgroup meta-analyses by continuous-flow and pulsatile device type demonstrated significant increased risk of death for both types of devices (HR 1.47, 95% CI: 1.22-1.76, p < 0.001 and 1.71, 95% CI: 1.19-2.45, p = 0.004, respectively). Patients who develop LVAD infections are younger, have higher BMIs and longer LVAD support times. Our data suggests that LVAD-related infections result in a 30% increase in postcardiac transplantation mortality. Strategies to prevent LVAD infections should be implemented to improve posttransplant outcomes in this high-risk population.

In Full Flow: Left Ventricular Assist Device Infections in the Modern Era

With the rising prevalence of heart disease in the United States, there is increasing reliance on durable mechanical circulatory support (MCS) to treat patients with end-stage heart failure. Left ventricular assist devices (LVADs), the most common form of durable MCS, are implanted mechanical pumps that connect to an external power source through a transcutaneous driveline. First-generation LVADs were bulky, pulsatile pumps that were frequently complicated by infection. Second-generation LVADs have an improved design, though infection remains a common and serious complication due to the inherent nature of implanted MCS. Infections can affect any component of the LVAD, with driveline infections being the most common. LVAD infections carry significant morbidity and mortality for LVAD patients. Therefore, it is paramount for the multidisciplinary team of clinicians caring for these patients to be familiar with this complication. We review the epidemiology, prevention, diagnosis, treatment, and outcomes of LVAD infections.

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.

Effects of Systemic and Device-Related Complications in Patients Bridged to Transplantation With Left Ventricular Assist Devices

BACKGROUND

The use of left ventricular assist devices (LVADs) as a bridge to heart transplantation has increased rapidly over the last 2 decades. We aim to explore the effect of pretransplant systemic and device-related complications on posttransplant survival for patients bridged with LVADs.

MATERIALS AND METHODS

The United Network of Organ Sharing (Organ Procurement and Transplantation Network) database was queried for all adult heart transplant recipients (aged ≥ 18 y) transplanted from April 1, 2015, to June 31, 2018. Device-related complications included thrombosis, device infection, device malfunction, life-threatening arrhythmia, and other device complications. Systemic complications included a new dialysis need or ventilator dependence between the time of listing and transplantation, transfusion, or systemic infection requiring treatment with intravenous antibiotics within 2 wk of transplantation.

RESULTS

A total of 2131 patients were identified as requiring LVAD support before transplantation. LVAD patients had high rates of preoperative systemic complications (53%) and high rates of device-related complications (42.7% experienced at least one device-related complication). Kaplan-Meier analysis revealed a significantly decreased 1-y survival for LVAD patients bridged to transplantation who experienced a pretransplant systemic complication (P = 0.041). Interestingly, preoperative device-related complications had no effect on 1-y posttransplantation survival (P = 0.93). Multivariate Cox modeling revealed that systemic complications were associated with a significantly increased risk of posttransplant mortality for LVAD patients (hazard ratio 1.45; P = 0.033).

CONCLUSIONS

Recipients who suffered a systemic complication while awaiting heart transplantation experienced higher short-term mortality rates. Device-related complications do not appear to impact posttransplantation outcomes.

The impact of infection among left ventricular assist device recipients on post-transplantation outcomes: A retrospective review

INTRODUCTION

Left ventricular assist device (LVAD) infections are common, and the consequences of LVAD infections on orthotopic heart transplantation (OHT) outcomes are not well described.

AIMS

The aim of this study was to describe clinical characteristics and evaluate risk factors for developing LVAD infections, and examine outcomes of LVAD-specific infections (VSI) after OHT.

METHODS

We retrospectively investigated the records of 74 consecutive patients at two institutions who had undergone LVAD placement and subsequent OHT between January 2007 and December 2012.

RESULTS

Forty-six of 74 (62%) LVAD recipients who underwent OHT had pre-transplant infections, and 18 (24%) had LVAD-specific infection (VSI), of which 71% were caused by gram-negative organisms. Of pre-transplant non-LVAD infections, Clostridium difficile infection (CDI) was the most common (26%) followed by urinary tract infection (UTI, 16%) and pneumonia (PNA 15%). Univariate analysis comparing subjects with VSI to those without VSI showed a significant association with time spent outside the hospital prior to transplantation (median 231.8 days vs 142.2 days, P < 0.03) and total time between VAD placement and OHT (244.0 days and 150.5 days, P < 0.002). Logistic regression was performed and significant predictors for VAD-related infection were age and the presence of diabetes, with type of device as an effect modifier. Six months post-OHT survival was not significantly affected by the presence of VSI prior to transplant. There was a trend toward an association between the presence of any infection and post-transplant rejection (P < 0.09). There were 10 post-transplant deaths by 6 months. Of these deaths, 4/10 (40%) were cardiopulmonary and 6/10 (60%) were related to infections.

CONCLUSIONS

Advanced age and presence of diabetes were predictors of VSI, as well as type of VAD device, although device choice is likely affected by many clinical factors including age and comorbidities, as well as institution-specific preferences. VSI was not associated with a decrease in 6-month post-OHT survival. However, infections remain the major causes of death by 6 months post-transplant. Certain infections are associated with an increased risk of rejection, which merits further investigation.

The value of fluorine-18 deoxyglucose positron emission tomography scans in patients with ventricular assist device specific infections†

BACKGROUND

Infections are major complications in patients with ventricular assist devices (VAD). Positron emission tomography with deoxyglucose marked by fluorine-18 ( 18 F-FDG PET/CT) is a diagnostic tool to scan for tissue with high metabolism as present in infections. The specificity of 18 F-FDG PET/CT to discriminate between infection and an aseptic reaction of the implanted device is not defined and its evaluation is the aim of this retrospective analysis.

METHODS

Until September 2015 a total of 100 patients underwent VAD implantations in our institution. Twenty-one patients (mean age 53.7 ± 14.3 years) had 29 PET-CT examinations for a suspected infection. All radiology reports were compared to clinical and intraoperative parameters. Infections were reported according to the guidelines of the International Society of Heart and Lung Transplantation. Follow-up was 222 days (range 107-484 days) after PET-CT scans and was complete in all patients.

RESULTS

In 7 patients PET-CT scan ruled out any VAD associated infection. Sixteen patients had a VAD specific infection. Two patients had false negative PET-CT scan results. The sensitivity of VAD-specific infections was 87.5%, the specificity 100%, the positive predictive value was 100% and the negative predictive value 86.7%. Seven patients had more than one PET-CT scans at different time points.

CONCLUSIONS

PET-CT scan findings showed a high specificity and positive predictive value for VAD-specific infections. Therefore, it may have the potential to guide the clinician in handling patients with infectious complications after VAD implantation.

Epidemiology and management of healthcare-associated bloodstream infections in non-neutropenic immunosuppressed patients: a review of the literature

Advancements in medicine have led to a considerable increase in the proportion of patients living with severe chronic diseases, malignancies, and HIV infections. Most of these conditions are associated with acquired immune-deficient states and treatment-related immunosuppression. Although infections as a result of neutropenia have long been recognized and strategies for management were developed, non-neutropenic immunosuppression has been overlooked. Recently, community-acquired infections in patients with frequent, significant exposure to healthcare settings and procedures have been classified as 'healthcare-associated infections' since they are more similar to hospital-acquired infections. Most of the non-neutropenic immunosuppressed patients have frequent contact with the healthcare system due to their chronic and severe diseases. In this review, we focus on the healthcare-associated bloodstream infections in the most common non-neutropenic immunosuppressive states and provide an update of the recent evidence for the management of these infections.

Use of Durable Continuous-Flow Ventricular Assist Devices in Patients on Immunosuppression

Durable ventricular assist device (VAD) therapy remains an important treatment for end-stage heart failure. Despite advancements in device design, postimplant infectious complications continue to plague this population. In this study, we aim to evaluate the use of durable VAD therapy in patients on active immunosuppression. All patients undergoing durable, continuous-flow VAD placement on active immunosuppression at our center from 2004 to 2012 were included in the analysis (group immunosuppressed [IS]; n = 13). Demographic data, comorbidities, device details, immunosuppression details including indication, postimplant infections, and outcomes were collected and compared with patients without immunosuppression (group non-IS; n = 259). Mean age in the IS group was 56.3 ± 12.4 years, and 12 patients (92.3%) were male. Twelve patients (92.3%) were implanted as a bridge to transplant. Incidence of any postimplant infection and device-related infection was 1.15 infections/patient × year and 0.38 infections/patient × year, respectively. Survival to discharge was 84.6% and 93.1% (p = 0.25), and 1 year survival was 75.0% and 83.1% (p = 0.47) in the IS and non-IS group, respectively. Mean duration of support was 384 ± 466 days, and mean follow-up was 2.1 ± 1.5 years. Active immunosuppression may lead to a modest increase in postimplant infection rate in durable VAD patients than in non-IS patients undergoing the same treatment; however, late on-device survival is not affected. Immunosuppression should not be considered an absolute contraindication to device implant.

Transplantation in a patient on extracorporeal membrane oxygenation with infective endocarditis, pericarditis and heparin-induced thrombocytopenia

Heart failure patients with pacemaker or defibrillator-associated endocarditis in cardiogenic shock have few treatment options. We present a case of an INTERMACS I patient who developed device infection, sepsis, bacterial pericarditis and heparin-induced thrombocytopenia. The patient was stabilized with extracorporeal membrane oxygenation and successfully transplanted.

Impact of Socioeconomic Status on Patients Supported With a Left Ventricular Assist Device: An Analysis of the UNOS Database (United Network for Organ Sharing)

BACKGROUND

Low socioeconomic status (SES) is a known risk factor for heart failure, mortality among those with heart failure, and poor post heart transplant (HT) outcomes. This study sought to determine whether SES is associated with decreased waitlist survival while on left ventricular assist device (LVADs) support and after HT.

METHODS AND RESULTS

A total of 3361 adult patients bridged to primary HT with an LVAD between May 2004 and April 2014 were identified in the UNOS database (United Network for Organ Sharing). SES was measured using the Agency for Healthcare Research and Quality SES index using data from the 2014 American Community Survey. In the study cohort, SES did not have an association with the combined end point of death or delisting on LVAD support (P=0.30). In a cause-specific unadjusted model, those in the top (hazard ratio, 1.55; 95% confidence interval, 1.14-2.11; P=0.005) and second greatest SES quartile (hazard ratio 1.50; 95% confidence interval, 1.10-2.04; P=0.01) had an increased risk of death on device support compared with the lowest SES quartile. Adjusting for clinical risk factors mitigated the increased risk. There was no association between SES and complications. Post-HT survival, both crude and adjusted, was decreased for patients in the lowest quartile of SES index compared with all other SES quartiles.

CONCLUSIONS

Freedom from waitlist death or delisting was not affected by SES. Patients with a higher SES had an increased unadjusted risk of waitlist mortality during LVAD support, which was mitigated by adjusting for increased comorbid conditions. Low SES was associated with worse post-HT outcomes. Further study is needed to confirm and understand a differential effect of SES on post-transplant outcomes that was not seen during LVAD support before HT.

The Impact of Obesity on Patients Bridged to Transplantation With Continuous-Flow Left Ventricular Assist Devices

OBJECTIVES

This study sought to determine if obese patients had worse post-left ventricular assist device (LVAD) implantation outcomes and if the implantation of an LVAD allowed for weight loss.

BACKGROUND

Obesity is a risk factor for cardiovascular disease including heart failure. Obese heart failure patients have better outcomes than those with normal weight; however, obese patients have worse outcomes after heart transplantation.

METHODS

Patients were identified in the United Network for Organ Sharing (UNOS) database that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. Patients were grouped according to body mass index (BMI) based on the World Health Organization classification.

RESULTS

Among 3,856 patients, the risk of death or delisting was not significantly different between BMI groups (p = 0.347). There was no increased risk of death (p = 0.234) or delisting (p = 0.918). The risk of complication requiring UNOS status upgrade was increased for those with class II obesity or greater (hazard ratio: 1.48; p = 0.004), driven by increased infection and thromboembolism. Obese patients had worse post-transplantation outcomes. Weight loss substantial enough to decrease BMI group was achieved by a small proportion of patients listed with class I obesity or greater (9.6% to 15.5%).

CONCLUSIONS

Patients with obesity had similar freedom from death or delisting while on LVAD support. However, class II obese or greater patients had an increased risk of complications requiring UNOS status upgrade compared with those with normal BMI during LVAD support and decreased post-transplantation survival. Weight loss on device therapy was possible, but uncommon. Careful consideration is needed when a bridge to weight loss strategy is proposed.

Ventricular assist devices as bridge to heart transplantation: impact on post-transplant infections

Background

Ventricular assist devices (VAD) are valuable options for patients with heart failure awaiting cardiac transplantation. We assessed the impact of pre-transplant VAD implantation on the incidence of post-transplant infections in a nationwide cohort of heart transplant recipients.

Methods

Heart transplant recipients included in the Swiss Transplant Cohort Study between May 2008 and December 2012 were analyzed. Cumulative incidence curves were used to calculate the incidence of bacterial or Candida infections (primary endpoint) and of other infections (secondary endpoint) after transplant. Cox regression models treating death as a competing risk were used to identify risk factors for the development of infection after transplant.

Results

Overall, 119 patients were included in the study, 35 with a VAD and 84 without VAD. Cumulative incidences of post-transplant bacterial or Candida infections were 37.7 % in VAD patients and 40.4 % in non-VAD patients. In multivariate analysis, the use of cotrimoxazole prophylaxis was the only variable associated with bacterial/Candida infections after transplant (HR 0.29 [95 % CI 0.15-0.57], p < 0.001), but presence of a VAD was not (HR 0.94, [95 % CI 0.38-2.32], p = 0.89, for continuous-flow devices, and HR 0.45 [0.15 – 1.34], p = 0.15, for other devices). Risk for post-transplant viral and all fungal infections was not increased in patients with VAD. One-year survival was 82.9 % (29/35) in the VAD group and 82.1 % (69/84) in the non-VAD group. All 6 patients in the VAD group that died after transplant had a history of pre-transplant VAD infection.

Conclusion

In this nationwide cohort of heart transplant recipients, the presence of VAD at the time of transplant had no influence on the development of post-transplant infections.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1658-0) contains supplementary material, which is available to authorized users.

Bloodstream infections after solid-organ transplantation

Solid-organ transplantation (SOT) has become the preferred strategy to treat a number of end-stage organ disease, because a continuous improvement in survival and quality of life. While preventive strategies has decreased the risk for classical opportunistic infections (such as viral, fungal and parasite infections), bacterial infections, and particularly bloodstream infections (BSIs) remain the most common and life-threatening complications in SOT recipients. The source of BSI after transplant depends on the type of transplantation, being urinary tract infection, pneumonia, and intraabdominal infections the most common infections occurring after kidney, lung and liver transplantation, respectively. The risk for candidemia is higher in abdominal-organ than in thoracic-organ transplantation. Currently, the increasing prevalence of multi-drug resistant (MDR) Gram-negative pathogens, such as extended-spectrum betalactamase-producing Enterobacteriaciae and carbapenem-resistant Klebsiella pneumoniae, is causing particular concerns in SOT recipients, a population which presents several risk factors for developing infections due to MDR organisms. The application of strict preventive policies to reduce the incidence of post transplant BSIs and to control the spread of MDR organisms, including the implementation of specific stewardship programs to avoid the overuse of antibiotics and antifungal drugs, are essential steps to reduce the impact of post transplant infections on allograft and patient outcomes.

Predictors of 30-day post-transplant mortality in patients bridged to transplantation with continuous-flow left ventricular assist devices--An analysis of the International Society for Heart and Lung Transplantation Transplant Registry

BACKGROUND

Continuous-flow (CF) left ventricular assist devices (LVADs) are standard of care for bridging patients to cardiac transplantation. However, existing data about preoperative factors influencing early post-transplant survival in these patients are limited. We sought to determine risk factors for mortality using a large international database.

METHODS

All patients in the International Society for Heart and Lung Transplantation Transplant Registry who were bridged to transplantation with CF LVADs between June 2008 and June 2012 were included. Risk factors for mortality within 30 days of transplant were identified. Statistical analysis included multivariable analysis and Kaplan-Meier survival analysis.

RESULTS

During the study period, 2,152 patients with CF LVADs underwent heart transplantation. Post-transplant survival was 95.5% at 30 days. Risk factors for mortality during this window included ventilator support at transplant (hazard ratio [HR] = 5.00, 95% confidence interval [CI] = 1.51-16.58), female recipient/male donor (compared with all other combinations, HR = 3.29, 95% CI = 1.90-5.72), history of hemodialysis (HR = 2.51, 95% CI = 1.14-5.51), and history of coronary bypass grafting (HR = 1.89, 95% CI = 1.19-3.00). Increasing recipient age (p = 0.002), body mass index (p = 0.002), creatinine (p = 0.004), and total bilirubin (p < 0.001) also were associated with an increase in mortality.

CONCLUSIONS

In patients supported with CF LVADs, risk factors for early mortality can be identified before transplant, including ventilator support, female recipient/male donor, increasing recipient age, and body mass index. Despite the inherent complexities of a reoperative surgery, patients bridged to transplant with CF LVADs have excellent peri-operative 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.

Left ventricular assist devices as a bridge to cardiac transplantation

Heart failure remains a significant cause of morbidity and mortality, affecting over five million patients in the United States. Continuous-flow left ventricular assist devices (LVAD) have become the standard of care for patients with end stage heart failure. This review highlights the current state of LVAD as a bridge to transplant (BTT) in patients requiring mechanical circulatory support (MCS).

Comparative Survival and Cost-Effectiveness of Advanced Therapies for End-Stage Heart Failure

Background—

Treatment options for end-stage heart failure include inotrope-dependent medical therapy, orthotopic heart transplantation (OHT), left ventricular assist device (LVAD) as destination therapy or bridge to transplant.

Methods and Results—

We developed a state-transition model to simulate 4 treatment options and associated morbidity and mortality. Transition probabilities, costs, and utilities were estimated from published sources. Calculated outcomes included survival, quality-adjusted life-years, and incremental cost-effectiveness. Sensitivity analyses were performed on model parameters to test robustness. Average life expectancy for OHT-eligible patients is estimated at 1.1 years, with 39% surviving to 1 year. OHT with a median wait time of 5.6 months is estimated to increase life expectancy to 8.5 years, and costs <$100 000/quality-adjusted life-year gained, relative to inotrope-dependent medical therapy. Bridge to transplant-LVAD followed by OHT further is estimated to increase life expectancy to 12.3 years, for $226 000/quality-adjusted life-year gained versus OHT. Among OHT-ineligible patients, mean life expectancy with inotrope-dependent medical therapy is estimated at 9.4 months, with 26% surviving to 1 year. Patients who instead received destination therapy-LVAD are estimated to live 4.4 years on average from extrapolation of recent constant hazard rates beyond the first year. This strategy costs $202 000/quality-adjusted life-year gained, relative to inotrope-dependent medical therapy. Patient’s age, time on wait list, and costs associated with care influence outcomes.

Conclusions—

Under most scenarios, OHT prolongs life and is cost effective in eligible patients. Bridge to transplant-LVAD is estimated to offer >3.8 additional life-years for patients waiting ≥6 months, but does not meet conventional cost-effectiveness thresholds. Destination therapy-LVAD significantly improves life expectancy in OHT-ineligible patients. However, further reductions in adverse events or improved quality of life are needed for destination therapy-LVAD to be cost effective.

Ventricular assist devices or inotropic agents in status 1A patients? Survival analysis of the United Network of Organ Sharing database

BACKGROUND

Improved outcomes as well as lack of donor hearts have increased the use of ventricular assist devices (VADs), rather than inotropic support, for bridging to transplantation. Recognizing that organ allocation in the highest status patients remains controversial, we sought to compare outcomes of patients with VADs and those receiving advanced medical therapy.

METHODS

The United Network of Organ Sharing (UNOS) database was used to compare survival on the waiting list and posttransplantation survival in status 1A heart transplantation patients receiving VADs or high-dose/dual inotropic therapy or an intraaortic balloon pump( IABP), or both. Adjusted survival was calculated using Cox's proportional hazard model.

RESULTS

Adjusted 1-year posttransplantation mortality was higher among patients with VADs compared with patients receiving inotropic agents alone (hazard ratio [HR], 1.48; p<0.05). Survival remained better for patients receiving inotropic agents alone in the post-2008 era (HR, 1.36; p=0.03) and among those with isolated left-sided support (HR, 1.33; p=0.008). When patients who received IABPs were added and analyzed after 2008, the left ventricular assist device (LVAD) group had similar survival (HR, 1.2; p=0.3). Survival on the waiting list, however, was superior among patients with LVADs (HR, 0.56; p<0.05). In a therapy transition analysis, failure of inotropic agents and the need for LVAD support was a consistent marker for significantly worse mortality (HR, 1.7; p<0.05).

CONCLUSIONS

Although posttransplantation survival is better for patients who are bridged to transplantation with inotropic treatment only, the cost of failure of inotropic agents is significant, with a nearly doubled mortality for those who later require VAD support. Survival on the waiting list appears to be improved among patients receiving VAD support. Careful selection of the appropriate bridging strategy continues to be a significant clinical challenge.

Infectious Complications of Mechanical Circulatory Support (MCS) Devices

Left-ventricular assist devices and other forms of mechanical circulatory support are increasingly important in the routine therapy of patients with end-stage congestive heart failure. Technology may help to decrease the rate of infections associated with these devices, but with larger numbers of implants being utilized across the globe, infections overall are becoming more commonplace. Becoming familiar with appropriate techniques for prevention and with the ideal approach to diagnostic and therapeutic strategies is key to managing mechanical circulatory support infections in this unique, but growing, patient population.