Outcomes of patients with infection related to a ventricular assist device after heart transplantation

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Infections in Patients With Left Ventricular Assist Devices: Current State and Future Perspectives

Mechanical circulatory support is increasingly being used as bridge-to-transplant and destination therapy in patients with advanced heart failure. Technologic improvements have led to increased patient survival and quality of life, but infection remains one of the leading adverse events following ventricular assist device (VAD) implantation. Infections can be classified as VAD-specific, VAD-related, and non-VAD infections. Risk of VAD-specific infections, such as driveline, pump pocket, and pump infections, remains for the duration of implantation. While adverse events are typically most common early (within 90 days of implantation), device-specific infection (primarily driveline) is a notable exception. No diminishment over time is seen, with event rates of 0.16 events per patient-year in both the early and late periods postimplantation. Management of VAD-specific infections requires aggressive treatment and chronic suppressive antimicrobial therapy is indicated when there is concern for seeding of the device. While surgical intervention/hardware removal is often necessary in prosthesis-related infections, this is not so easily accomplished with VADs. This review outlines the current state of infections in patients supported with VAD therapy and discusses future directions, including possibilities with fully implantable devices and novel approaches to treatment.

Daptomycin Pharmacokinetics in Blood and Wound Fluid in Critical Ill Patients with Left Ventricle Assist Devices

Daptomycin is a cyclic lipopeptide antibiotic with bactericidal effects against multidrug-resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). For critically ill patients, especially in the presence of implants, daptomycin is an important therapeutic option. Left ventricle assist devices (LVADs) can be utilized for intensive care patients with end-stage heart failure as a bridge to transplant. We conducted a single-center prospective trial with critically ill adults with LVAD who received prophylactic anti-infective therapy with daptomycin. Our study aimed to evaluate the pharmacokinetics of daptomycin in the blood serum and wound fluids after LVAD implantation. Daptomycin concentration were assessed over three days using high-performance liquid chromatography (HPLC). We detected a high correlation between blood serum and wound fluid daptomycin concentration at 12 h (IC95%: 0.64 to 0.95; r = 0.86; p < 0.001) and 24 h (IC95%: -0.38 to 0.92; r = 0.76; p < 0.001) after antibiotic administration. Our pilot clinical study provides new insights into the pharmacokinetics of daptomycin from the blood into wound fluids of critically ill patients with LVADs.

Durable mechanical circulatory support as bridge to heart transplantation

PURPOSE OF REVIEW

Durable mechanical circulatory support (MCS) technology has changed over time as devices have evolved from pulsatile to continuous flow support. In this review, we discuss recent data and substantial changes to current practice as it pertains to the subject of current era durable left ventricular assist devices (LVADs) as a bridge to heart transplantation.

RECENT FINDINGS

The results of heart transplantation in patients bridged with durable LVAD support are satisfactory even after prolonged duration of support. Reports of recent experience with LVAD related infection suggest that this complication has limited impact on post-transplant outcomes. Important sex-related disparities continue to exist following durable LVAD implantation. Recent changes in the United Network for Organ Sharing donor heart allocation policy have resulted in a drastic decline in the use of durable LVAD support for Bridge to Transplant in the United States.

SUMMARY

Durable MCS in the form of LVAD as a BTT strategy continues to evolve over time. Optimization of its role in the treatment of end-stage heart failure, particularly in females will need to be the focus of future research.

IgM-enriched immunoglobulin as adjuvant therapy for heart transplant after infection of left ventricular assist devices

Patients undergoing heart transplantation (HTx) with active infection of left ventricular assist devices (LVAD) are at high risk for postoperative infections. Between 2021 and 2022, five (P1-P5) of a total of n = 44 patients underwent HTx in our department while suffering from LVAD infection. Postoperatively, patients received adjuvant IgM-enriched human intravenous immunoglobulin (IGM-IVIG), consisting of 76% IgG, 12% IgM, and 12% IgA as a novel approach to prevent infective complications. While in P1, P2, and P4, LVAD driveline infection was known before HTx; in P3 and P5, abscess of device pocket was found incidentally during HTx. After a single dose of IGM-IVIG, all patients showed adequate rise in serum immunoglobulins. In the postoperative course, no patient developed infective complications. All patients were successfully discharged and in good condition at the last follow-up. Therefore, IGM-IVIG seems to be an effective adjuvant treatment for patients undergoing HTx with LVAD infections.

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.

The Predictive Value of Changes in Body Mass Index for the Incidence of Device-Specific Infections in Patients With Implantable Left Ventricular Assist Devices

BACKGROUND

Implantable left ventricular assist devices (LVAD) have improved quality of life and survival in patients with advanced heart failure. However, LVAD-specific infections and predicting which patients will develop infections remain challenging. This study investigated whether changes in body mass index (BMI) during hospitalization following LVAD implantation are associated with LVAD-specific infections within 1 year of implantation.

METHODS AND RESULTS

Patients (n=135) undergoing LVAD implantation were retrospectively divided into 2 groups based on changes in BMI from LVAD implantation to discharge: those with and without decreases in BMI. Each group was further subdivided according to baseline albumin concentrations (high [>3.7 g/dL] and low [≤3.7 g/dL]). Twenty patients developed LVAD-specific infections within 1 year. Receiver operating characteristic curve analysis resulted in a ∆BMI cut-off of less than -0.128 kg/m2. In multivariate analysis, younger patients and those with decreases in BMI had significantly higher rates of LVAD-specific infection (P=0.010 and P=0.035, respectively). LVAD-specific infection rates were significantly higher for patients with low albumin and decreases in BMI than for patients with low albumin but no decrease in BMI.

CONCLUSIONS

Decreases in BMI during hospitalization after LVAD implantation and younger age were independently associated with LVAD-specific infection within 1 year. Strict patient management may be needed to avoid decreases in BMI during hospitalization after LVAD implantation, particularly in patients with low baseline albumin concentrations.

Percutaneous mitral valve repair assisted by a catheter-based circulatory support device in a heart transplant patient

BACKGROUND

Systemic infections and chronic graft rejection represent common causes of mortality and morbidity in heart transplant patients. In severe cases, cardiogenic shock (CS) may occur and require hemodynamic stabilization with temporary mechanical circulatory support (tempMCS). Under these devastating circumstances, treatment of sequelae of left ventricular dysfunction, such as secondary mitral regurgitation (MR) is challenging, especially when surgical repair is deemed futile. In nontransplant patients, interventional mitral valve repair strategies such as the MitraClip system (Abbott Cardiovascular) have been used to successfully treat secondary MR and allow for weaning from tempMCS.

CASE SUMMARY

We report about the first patient in whom profound CS after heart transplantation was stabilized with tempMCS followed by interventional elimination of secondary MR.

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.

Management and Outcome of Left Ventricular Assist Device Infections in Patients Undergoing Cardiac Transplantation

Background

Postoperative management of patients undergoing cardiac transplantation with an infected left ventricular assist device (LVAD) is unclear.

Methods

We retrospectively screened all adults with an LVAD who underwent cardiac transplantation at our institution from 2010 through 2018. We selected all cases of LVAD-specific and LVAD-related infections who were receiving antimicrobial therapy as initial treatment course or chronic suppression at the time of cardiac transplantation. Non-LVAD infections, superficial driveline-infection, or concurrent use of right ventricular assist device or extracorporeal membrane oxygenation device were excluded.

Results

A total of 54 cases met study criteria with 18 of 54 (33.6%) classified as LVAD- specific or related infections and 36 of 54 (66.6%) as noninfected. cases of lvad infection had a higher median charlson comorbidity Index score at the time of transplantation compared with noninfected cases (P = .005). Of the 18 cases of infection, 13 of 18 (72.2%) were classified as LVAD-specific and 5 of 18 (27.8%) were classified as LVAD-related. Nine of 13 (69.2%) cases had proven LVAD-specific infections. Antimicrobial therapy was extended posttransplant to treat preceding LVAD-specific infection in all 9 cases (9 of 13, 69.2%) with a median duration of 14 days (interquartile range, 14–28). After LVAD removal, antimicrobial treatment was not continued for preceding LVAD-related infections.

Conclusions

Patients with an LVAD-specific infection were treated with 2 weeks of pathogen-directed therapy postheart transplant without any relapses. For those without LVAD-specific infection or uncomplicated LVAD-related bacteremia who had completed antimicrobial therapy pretransplant, antibiotics were discontinued after standard perioperative prophylaxis and no relapses were observed.