Factors associated with acute limb ischemia in cardiogenic shock and downstream clinical outcomes: Insights from the Cardiogenic Shock Working Group

BACKGROUND

There are limited data depicting the prevalence and ramifications of acute limb ischemia (ALI) among cardiogenic shock (CS) patients.

METHODS

We employed data from the Cardiogenic Shock Working Group (CSWG), a consortium including 33 sites. We constructed a multi-variable logistic regression to examine the association between clinical factors and ALI, we generated another logistic regression model to ascertain the association of ALI with mortality.

RESULTS

There were 7,070 patients with CS and 399 (5.6%) developed ALI. Patients with ALI were more likely to be female (40.4% vs 29.4%) and have peripheral arterial disease (13.8% vs 8.3%). Stratified by maximum society for cardiovascular angiography & intervention (SCAI) shock stage, the rates of ALI were stage B 0.0%, stage C 1.8%, stage D 4.1%, and stage E 10.3%. Factors associated with higher risk for ALI included: peripheral vascular disease OR 2.24 (95% CI: 1.53-3.23; p < 0.01) and ≥2 mechanical circulatory support (MCS) devices OR 1.66 (95% CI: 1.24-2.21, p < 0.01). ALI was highest for venous-arterial extracorporeal membrane oxygenation (VA-ECMO) patients (11.6%) or VA-ECMO+ intra-aortic balloon pump (IABP)/Impella CP (16.6%) yet use of distal perfusion catheters was less than 50%. Mortality was 38.0% for CS patients without ALI but 57.4% for CS patients with ALI. ALI was significantly associated with mortality, adjusted OR 1.40 (95% CI 1.01-1.95, p < 0.01).

CONCLUSIONS

The rate of ALI was 6% among CS patients. Factors most associated with ALI include peripheral vascular disease and multiple MCS devices. The downstream ramifications of ALI were dire with a considerably higher risk of mortality.

Sexual Quality of Life in Left Ventricular Assist Device Patients and Their Partners

BACKGROUND

Living with a left ventricular assist device (LVAD) comes with potentially burdensome aspects posed by, for example, battery packs and device drivelines. We aim to describe the impact of living with a durable LVAD on sexual quality of life (QOL), depression, and anxiety in patients and their partners.

METHODS AND RESULTS

In this single-center, prospective, observational study, patients ≥4 months after LVAD implantation and their partners completed the Sexual Activities in Left Ventricular Assist Device Patients or Partners questionnaire to assess their sexual QOL, the 8-item Patient Health Questionnaire (PHQ-8) to assess symptoms of depression and the 7-item Generalized Anxiety Disorder (GAD-7) to assess symptoms of anxiety. Sixty patients and 60 partners completed the questionnaires 2.3 ± 1.9 years after implantation. Eighty-seven percent of the patients and 13% of partners were male. The mean age of patients was 57.4 ± 13.3 years, with 90% living with their partner. Ten percent of patients and 18% of partners had a current diagnosis of a psychological condition, most frequently depression and/or anxiety. Overall, 49% of participants indicated the LVAD influenced their sexual activity (patients 53% vs partners 45%; P = .33). Disturbances from the driveline were the most common problem indicated. Twenty-four percent of participants had scored in the mild to moderate depression range on the PHQ-8 and 28% scored in the mild to severe anxiety range on the GAD-7. The median total GAD-7 (1 [interquartile range (IQR) 0-4.25] vs 2.5 [IQR 0-5]; P = .06) were comparable between patients and partners; whereas patients had a higher total PHQ-8 score (3 [IQR 0-5.25] vs 1 [IQR 0-3.25]; P = .02). A preference to receive information regarding sexuality while on LVAD support was indicated by 54% of participants and did not differ between patients and partners (P > .99). Written resources were the most commonly preferred source of information.

CONCLUSIONS

LVADs severely affect the sexual QOL for patients and their partners. The presence of a driveline is a major cause for concern. Patients prefer receiving written information on how to improve their sexual QOL.

Three-year outcomes of de novo tacrolimus extended-release tablets (LCPT) compared to twice-daily tacrolimus in adult heart transplantation

BACKGROUND

Extended-release tacrolimus for prophylaxis of allograft rejection in heart transplant (HT) recipients is currently not FDA-approved. One such extended-release formulation of tacrolimus known as LCPT allows once-daily dosing and improves bioavailability compared to immediate-release (IR-) tacrolimus. We compared long-term efficacy and safety of LCPT to IR-tacrolimus applied de novo in adult OHT recipients.

METHODS

25 prospective recipients on LCPT at our center from 2017 to 2019 were matched 1:2 with historical control recipients treated with IR-tacrolimus based on age, gender, and baseline creatinine. The primary composite outcome of death, acute cellular rejection, and/or new graft dysfunction within 3 years following transplant was compared between groups using non-inferiority analysis.

RESULTS

LCPT demonstrated non-inferiority to IR-tacrolimus, with a primary outcome risk reduction of 16% (90%CI, -37%, -1%, non-inferiority p = 0.002) up to 3 years following heart transplant. Up to 3-years post-transplant, 14 patients remained on once-daily LCPT and 10 patients were switched to IR-tacrolimus due to lack of insurance coverage. There were no significant differences in the rate of chronic kidney disease requiring dialysis, cytomegalovirus requiring treatment, cardiac allograft vasculopathy, and malignancy within 3 years following transplant.

CONCLUSION

LCPT is non-inferior in efficacy to IR-tacrolimus in heart transplantation with a similar safety profile. Narrowly-constrained FDA labels specific to kidney transplant remain a barrier to consistent access to many immunosuppressant medications for recipients of non-kidney solid organs. We recommend the FDA consider developing facile pathways for expanding the approved label of extended-release tacrolimus formulations to heart transplant recipients.

Molecular states associated with dysfunction and graft loss in heart transplants

BACKGROUND

We explored the changes in gene expression correlating with dysfunction and graft failure in endomyocardial biopsies.

METHODS

Genome-wide microarrays (19,462 genes) were used to define mRNA changes correlating with dysfunction (left ventricular ejection fraction [LVEF] ≤ 55) and risk of graft loss within 3 years postbiopsy. LVEF data was available for 1,013 biopsies and survival data for 779 patients (74 losses). Molecular classifiers were built for predicting dysfunction (LVEF ≤ 55) and postbiopsy 3-year survival.

RESULTS

Dysfunction is correlated with dedifferentiation-decreased expression of normal heart transcripts, for example, solute carriers, along with increased expression of inflammation genes. Many genes with reduced expression in dysfunction were matrix genes such as fibulin 1 and decorin. Gene ontology (GO) categories suggested matrix remodeling and inflammation, not rejection. Genes associated with the risk of failure postbiopsy overlapped dysfunction genes but also included genes affecting microcirculation, for example, arginase 2, which reduces NO production, and endothelin 1. GO terms also reflected increased glycolysis and response to hypoxia, but decreased VEGF and angiogenesis pathways. T cell-mediated rejection was associated with reduced survival and antibody-mediated rejection with relatively good survival, but the main determinants of survival were features of parenchymal injury. Both dysfunction and graft loss were correlated with increased biopsy expression of BNP (gene NPPB). Survival probability classifiers divided hearts into risk quintiles, with actuarial 3-year postbiopsy survival >95% for the highest versus 50% for the lowest.

CONCLUSIONS

Dysfunction in transplanted hearts reflects dedifferentiation, decreased matrix genes, injury, and inflammation. The risk of short-term loss includes these changes but is also associated with microcirculation abnormalities, glycolysis, and response to hypoxia.

The impact of active cytomegalovirus infection on donor-derived cell-free DNA testing in heart transplant recipients

BACKGROUND

Little is known about the relationship between cytomegalovirus (CMV) infections and donor-derived cell-free DNA (dd-cfDNA) in heart transplant recipients.

METHODS

In our study, CMV and dd-cfDNA results were prospectively collected on single-organ heart transplant recipients. If the CMV study was positive, a CMV study with dd-cfDNA was repeated 1-3 months later. The primary aim was to compare dd-cfDNA between patients with positive and negative CMV results.

RESULTS

Of 44 patients enrolled between August 2022 and April 2023, 12 tested positive for CMV infections, 25 were included as controls, and seven patients with a viral infection without CMV were excluded. Baseline characteristics did not differ significantly between CMV-positive and CMV-negative patients with the exception of a later median time post-transplant in the CMV-positive group (253 days vs. 120 days, p = .03). Dd-cfDNA levels were significantly higher in patients with CMV infections compared to those without (p < .001) with more patients in the CMV positive group showing dd-cfDNA results ≥.12% (75% vs. 8%, p < .001) and ≥.20% (58% vs. 8%, p = .002). Each 1 log10 copy/ml reduction in CMV viral load from visit 1 to visit 2 was associated with a.23% reduction in log10 dd-cfDNA (p = .002).

CONCLUSION

Our findings suggest that active CMV infections may raise dd-cfDNA levels in patients following heart transplantation. Larger studies are needed to validate these preliminary findings.

Early elevated donor-derived cell-free DNA levels in heart transplant recipients following precision-controlled cardiac transport system or ice-cooled organ transport

BACKGROUND

Recent innovations in temperature-controlled cardiac transportation allow for static hypothermic preservation of transplant organs during transportation. We assessed differences in donor-derived cell-free DNA (dd-cfDNA) using the SherpaPak cardiac transport system (SCTS) and traditional ice transportation.

METHODS

Single-organ heart transplant recipients between January 2020 and January 2022 were included if they had dd-cfDNA measures ≤6 weeks post-transplant along with the baseline biopsy at 6 weeks as part of the surveillance protocol and no biopsy-confirmed rejection ≤90 days. Elevated dd-cfDNA ≥.20% were compared between groups using logistic regression including a subject effect.

RESULTS

Of 65 hearts transplanted, 30 were transported with SCTS and 35 on ice. Recipient characteristics were similar between groups. Donors in the SCTS group were older (34 vs. 40 years, p = .04) with a longer total ischemic time (171 vs. 212 min, p = .002). Recipients in the SCTS group had a greater risk of elevated dd-cfDNA unadjusted and adjusted for donor age, and prolonged ischemic times > 3.5 h (Unadjusted odds ratio: 4.9, 95%-CI: 1.08-22.5, p = .039 and Adjusted odds ratio: 5.5, 95%-CI: 1.03-29.6, p = .046). Primary graft dysfunction rates and 1-year mortality were comparable between groups.

CONCLUSION

Elevated dd-cfDNA in patients procured with SCTS may indicate that graft injury was not negated relative to ice transport. However, there were no clinical differences noted in short or long-term outcomes including mortality despite a longer ischemic time in the SCTS group.

Concurrent valvular procedures during left ventricular assist device implantation and outcomes: A comprehensive analysis of the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 trial portfolio

BACKGROUND

Correction of valvular disease is often undertaken during left ventricular assist device (LVAD) implantation with uncertain benefit. We analyzed clinical outcomes with HeartMate 3 (HM3; Abbott) LVAD implantation in those with various concurrent valve procedures (HM3+VP) with those with an isolated LVAD implant (HM3 alone).

METHODS

The study included 2200 patients with HM3 implanted within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial portfolio who underwent 820 concurrent procedures among which 466 (21.8%) were HM3+VP. VPs included 101 aortic, 61 mitral, 163 tricuspid; 85 patients had multiple VPs. Perioperative complications, major adverse events, and survival were analyzed.

RESULTS

Patients who underwent HM3+VP had higher-acuity Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles (1-2: 41% vs 31%) compared with no VPs (P < .05). The cardiopulmonary bypass time (124 vs 76 minutes; P < .0001) and hospital length of stay (20 vs 18 days; P < .0001) were longer in HM3+VP. A higher incidence of stroke (4.9% vs 2.4%), bleeding (33.9% vs 23.8%), and right heart failure (41.5% vs 29.6%) was noted in HM3+VP at 0 to 30 days (P < .01), with no difference in 30-day mortality (3.9% vs 3.3%) or 2-year survival (81.7% vs 80.8%). Analysis of individual VP showed no differences in survival compared to HM3 alone. No differences were noted among patients with either significant mitral (moderate or worse) or tricuspid (moderate or worse) regurgitation with or without corrective surgery.

CONCLUSIONS

Concurrent VPs, commonly performed during LVAD implantation, are associated with increased morbidity during the index hospitalization, with no effect on short- and long-term survival. There is sufficient equipoise to consider a randomized trial on the benefit of commonly performed VPs (such as mitral or tricuspid regurgitation correction), during LVAD implantation.

Challenges with the current United Network for Organ Sharing heart allocation system

PURPOSE OF REVIEW

The revised United States heart organ allocation system was launched in October 2018. In this review, we summarize this United Network for Organ Sharing (UNOS) policy and describe intended and unintended consequences.

RECENT FINDINGS

Although early studies published after the change suggested postheart transplant survival declined at 6 months and 1 year, recent publications with longer follow-up time have confirmed comparable posttransplant survival in adjusted models and several patient cohorts. Moreover, the new allocation decreased overall waitlist time from 112 to 39 days ( P  < 0.001). Mean ischemic time increased because of greater distances traveled to acquire donor hearts under broader sharing. Despite the intention to decrease exception requests by expanding the number of priority tiers to provide more granular risk stratification, ∼30% of patients remain waitlisted under exception status. Left-ventricular assist device (LVAD) implants are declining and the number of LVAD patients on the transplant list has decreased dramatically after the allocation system change.

SUMMARY

As the next allocation system is developed, it is imperative to curtail the use of temporary mechanical support as a strategy solely for listing purposes, identify attributes that more clearly stratify the severity of illness, provide greater oversight of exception requests, and address concerns regarding patients with durable LVADs.

Predictors of 5-Year Mortality in Patients Managed With a Magnetically Levitated Left Ventricular Assist Device

BACKGROUND

In advanced heart failure patients implanted with a fully magnetically levitated HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD), it is unknown how preimplant factors and postimplant index hospitalization events influence 5-year mortality in those able to be discharged.

OBJECTIVES

The goal was to identify risk predictors of mortality through 5 years among HM3 LVAD recipients conditional on discharge from index hospitalization in the MOMENTUM 3 pivotal trial.

METHODS

This analysis evaluated 485 of 515 (94%) patients discharged after implantation of the HM3 LVAD. Preimplant (baseline), implant surgery, and index hospitalization characteristics were analyzed individually, and as multivariable predictors for mortality risk through 5 years.

RESULTS

Cumulative 5-year mortality in the cohort (median age: 62 years, 80% male, 65% White, 61% destination therapy due to transplant ineligibility) was 38%. Two preimplant characteristics (elevated blood urea nitrogen and prior coronary artery bypass graft or valve procedure) and 3 postimplant characteristics (hemocompatibility-related adverse events, ventricular arrhythmias, and estimated glomerular filtration rate <60 mL/min/1.73 m2 at discharge) were predictors of 5-year mortality. In 171 of 485 patients (35.3%) without any risk predictors, 5-year mortality was reduced to 22.6% (95% CI: 15.4%-32.7%). Even among those with 1 or more predictors, mortality was <50% at 5 years (45.7% [95% CI: 39.0%-52.8%]).

CONCLUSIONS

Long-term survival in successfully discharged HM3 LVAD recipients is largely influenced by clinical events experienced during the index surgical hospitalization in tandem with baseline factors, with mortality of <50% at 5 years. In patients without identified predictors of risk, long-term 5-year mortality is low and rivals that achieved with heart transplantation, even though most were implanted with destination therapy intent. (MOMENTUM 3 IDE Clinical Study Protocol, NCT02224755; MOMENTUM 3 Pivotal Cohort Extended Follow-up PAS, NCT03982979).

Safety and efficacy of ProtekDuo right ventricular assist device: A systemic review

BACKGROUND

Right ventricular failure is associated with increased morbidity and mortality. The ProtekDuo (Livanova, Uk) is a dual-lumen cannula that allows for percutaneous right ventricular support and may be connected to a centrifugal blood pump such as the TandemHeart or LifeSparc (Livanova, UK). This systematic review aims to evaluate the safety and efficacy of ProtekDuo right ventricular support and evaluate potential clinical variables that can influence outcomes.

METHODS

PubMed, MEDLINE, SCOPUS, EMBASE, and the Cochrane Library were systematically searched. Studies meeting inclusion criteria, where ProtekDuo was used as the right ventricular assist device with reported numerical death counts for mortality as outcome measures. The primary endpoints were in-hospital 30-day and 1-year mortality rates. Secondary endpoints included ICU length of stay, conversion rates to surgical RVADs, ProtekDuo wean rates, duration of use of ProtekDuo, and adverse event rates.

RESULTS

Of 49 studies reviewed, 7 met inclusion criteria with study periods between October 2014 and November 2019. ProtekDuo was utilized due to RV failure post-LVAD insertion in 64.8% (68/105) of patients. In-hospital mortality, 30-day mortality, and 1-year mortality ranged between 9%-46%, 15%-40%, and 19%-40%, respectively. Weaning from ProtekDuo and conversion to surgical RVAD ranged between 24%-91% and 11%-35%, respectively. The ICU stay average ranged from 15.8 to 36 days and ProtekDuo mean support duration ranged from 10.5 to 58 days.

CONCLUSION

The ProtekDuo cannula is increasingly utilized as a right ventricular support device. Despite the sparse retrospective data available with variable patient characteristics and study design, percutaneous RV mechanical support via ProtekDuo cannula is a safe and feasible option.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

Heart transplant Recipients' perspectives on invasive versus Non-invasive graft failure surveillance Methods

BACKGROUND

Heart transplant recipients must regularly be assessed for graft rejection; however, endomyocardial biopsy (EMB), can be stressful, painful, and inconvenient. AlloMap® is the only commercially available non-invasive test for graft rejection. Current guidelines include AlloMap® testing in low-risk patients OBJECTIVES: To examine the patients' perspective, this study compared patients' experiences of AlloMap® and EMB surveillance at our center.

METHODS

We enrolled consecutive heart transplant recipients who were to undergo routine EMB and AlloMap® testing (on different visits) to quantify their anxiety on the GAD-7 scale and their pain level on the Polyclinic Pain Scale. We assessed paired differences of anxiety and pain within patients according to surveillance method.

RESULTS

We studied 43 participants (median age 60.5[54, 66] years; 35(81%) men; 27(63%) Caucasian). The median GAD-7 scores were 1[0, 4] and 2[0, 5] prior to EMB and AlloMap®, respectively (paired difference: 0[-1, 1],P = 0.323). The median pain scores were 1[0, 1] and 0[0, 0] for EMB and AlloMap®, respectively. Patients experienced less pain with AlloMap® testing compared to EMB (EMB-AlloMap;1[0, 1],P = 0.006). Seven (16%) participants experienced a total of 9 adverse events (pain, bruising, bleeding, swelling) from EMB vs 2(5%) participants who experienced a total of 3 adverse events (pain, bruising) from AlloMap®(P = 0.059).

CONCLUSION

Heart transplant recipients had less pain and fewer adverse events while undergoing graft rejection surveillance with AlloMap® testing compared to EMB. An additional benefit of AlloMap® testing is that it may be performed at home and reduce these high-risk patients' infectious exposures.

Donor heart selection: Evidence-based guidelines for providers

The proposed donor heart selection guidelines provide evidence-based and expert-consensus recommendations for the selection of donor hearts following brain death. These recommendations were compiled by an international panel of experts based on an extensive literature review.

North American Practice-Based Recommendations for Transjugular Intrahepatic Portosystemic Shunts in Portal Hypertension

Complications of portal hypertension, including ascites, gastrointestinal bleeding, hepatic hydrothorax, and hepatic encephalopathy, are associated with significant morbidity and mortality. Despite few high-quality randomized controlled trials to guide therapeutic decisions, transjugular intrahepatic portosystemic shunt (TIPS) creation has emerged as a crucial therapeutic option to treat complications of portal hypertension. In North America, the decision to perform TIPS involves gastroenterologists, hepatologists, and interventional radiologists, but TIPS creation is performed by interventional radiologists. This is in contrast to other parts of the world where TIPS creation is performed primarily by hepatologists. Thus, the successful use of TIPS in North America is dependent on a multidisciplinary approach and technical expertise, so as to optimize outcomes. Recently, new procedural techniques, TIPS stent technology, and indications for TIPS have emerged. As a result, practices and outcomes vary greatly across institutions and significant knowledge gaps exist. In this consensus statement, the Advancing Liver Therapeutic Approaches group critically reviews the application of TIPS in the management of portal hypertension. Advancing Liver Therapeutic Approaches convened a multidisciplinary group of North American experts from hepatology, interventional radiology, transplant surgery, nephrology, cardiology, pulmonology, and hematology to critically review existing literature and develop practice-based recommendations for the use of TIPS in patients with any cause of portal hypertension in terms of candidate selection, procedural best practices and, post-TIPS management; and to develop areas of consensus for TIPS indications and the prevention of complications. Finally, future research directions are identified related to TIPS for the management of portal hypertension.

Special Considerations in the Care of Women With Advanced Heart Failure

Advanced heart failure (AHF) is associated with increased morbidity and mortality, and greater healthcare utilization. Recognition requires a thorough clinical assessment and appropriate risk stratification. There are persisting inequities in the allocation of AHF therapies. Women are less likely to be referred for evaluation of candidacy for heart transplantation or left ventricular assist device despite facing a higher risk of AHF-related mortality. Sex-specific risk factors influence progression to advanced disease and should be considered when evaluating women for advanced therapies. The purpose of this review is to discuss the role of sex hormones on the pathophysiology of AHF, describe the clinical presentation, diagnostic evaluation and definitive therapies of AHF in women with special attention to pregnancy, lactation, contraception and menopause. Future studies are needed to address areas of equipoise in the care of women with AHF.

Trends in Hospital Admissions for Systolic and Diastolic Heart Failure in the United States Between 2004 and 2017

Heart failure (HF) affects 6 million people in the United States and costs $30 billion annually. It is unclear whether improvements in length of stay and mortality over the last few decades hold true for both systolic and diastolic HF. To better assess the epidemiological and economic burden of HF, we assessed the trends in outcomes and costs for both systolic and diastolic HF. We identified hospitalizations for systolic and diastolic HF in the National Inpatient Sample database and evaluated trends over the period from 2004 to 2017, adjusting for demographics and co-morbidities. The proportion of patients admitted with an exacerbation of systolic HF increased from 42% to 63% over the study period. We found an overall decreasing trend between 2004 and 2011 in the length of stay for HF in general with a sharper decrease in diastolic than systolic HF. Inpatient mortality decreased between 2004 and 2007 and stabilized between 2008 and 2016. Systolic HF was associated with higher mortality than diastolic HF. The total inflation-adjusted cost did not change significantly over the study period, with systolic HF costing, on average, $3,036 more than diastolic HF per admission. In conclusion, systolic HF overtook diastolic HF, accounting for most HF hospitalizations in 2008. The higher hospitalization costs for systolic HF relative to diastolic HF may have resulted, in part, from greater use of advanced support devices in patients with systolic HF.

The “Right” Definition for Post–Left Ventricular Assist Device Right Heart Failure: The More We Learn, the Less We Know

Right heart failure is a major cause of morbidity and mortality following left ventricular assist device implantation. Over the past few decades, the definition proposed by the Interagency Registry of Mechanical Circulatory Support and Society of Thoracic Surgeons has continually evolved to better identify this complex pathology. We propose that the latest definition proposed by the Mechanical Circulatory Support Academic Research Consortium in 2020 will increase our recognition and understanding of this complex disease phenomenon.

Observed elevated donor-derived cell free DNA in orthotopic heart transplant recipients without clinical evidence of rejection

Donor‐derived cell free DNA (dd‐cfDNA) has rapidly become part of rejection surveillance following orthotopic heart transplantation. However, some patients show elevated dd‐cfDNA without clinical evidence of rejection. With the aim to provide a clinical description of this subpopulation, we retrospectively analyzed 35 cardiac transplant recipients at our center who experienced elevated (≥.20%) dd‐cfDNA in the absence of clinical rejection, out of a total 106 recipients who had dd‐cfDNA results available during the first year. The median time to first elevated dd‐cfDNA level was 46 days, and the highest dd‐cfDNA recorded within 1 year was .31% [inter‐quartile range, .23–.45]. Twenty‐two (63%) patients experienced infections (cytomegalovirus (CMV) or other), and 16 (46%) presented with de novo donor‐specific antibodies. Cluster analysis revealed four distinct groups characterized by (a) subclinical rejection with 50% CMV (n = 16), (b) non‐CMV infections and the longest time to first elevated dd‐cfDNA (187 days) (n = 8), (c) right ventricular dysfunction (n = 6), and (d) women who showed the youngest median age (45 years) and highest median dd‐cfDNA (.50%) (n = 5). Continued prospective analysis is needed to determine if these observations warrant changes in patient management to optimize the utilization of this vital non‐invasive graft surveillance tool.

Urinary Cell-Cycle Arrest Biomarkers as Early Predictors of Acute Kidney Injury After Ventricular Assist Device Implantation or Cardiac Transplantation

OBJECTIVES

Acute kidney injury (AKI) remains a leading source of morbidity and mortality after cardiothoracic surgery. Insulin-like growth factor-binding protein 7 (IGFBP7), and tissue inhibitor of metalloproteinases-2 (TIMP-2), are novel early-phase renal biomarkers that have been validated as sensitive predictors of AKI. Here the authors studied the efficacy of these biomarkers for predicting AKI after left ventricular assist device (LVAD) implantation and cardiac transplantation.

DESIGN/SETTING/PARTICIPANTS/INTERVENTIONS

This was a prospective study of 73 patients undergoing LVAD implantation (n = 37) or heart transplant (n = 36) from 2016 to 2017 at the authors' center. TIMP-2 and IGFBP7 were measured with the NephroCheck Test on urine samples before surgery and one-to-six hours after surgery. NephroCheck scores were assessed as predictors of moderate/severe AKI (Kidney Disease International Global Outcomes 2/3 creatinine criteria) within 48 hours of surgery, and the association with survival to one year was investigated.

MEASUREMENTS AND MAIN RESULTS

The LVAD and transplant cohorts overall were similar in demographics and baseline creatinine (p > 0.05), with the exception of having more African-American patients in the LVAD arm (p = 0.003). Eleven (30%) LVAD and 16 (44%) transplant patients developed moderate/severe AKI. Overall, AKI was associated with postsurgery NephroCheck (odds ratio [95% confidence interval] for 0.1 mg/dL increase: 1.36 [1.04-1.79]; p = 0.03), but not with baseline NephroCheck (p = 0.92). When analyzed by cohort, this effect remained for LVAD (1.68 [1.05-2.71]; p = 0.03) but not for transplant (p = 0.15). Receiver operating characteristic analysis showed postoperative NephroCheck to be superior to baseline creatinine in LVAD (p = 0.046). Furthermore, an increase of 0.1 mg/dL in postoperative NephroCheck was associated with a 10% increase in the risk of mortality (adjusted hazard ratio: 1.11 [1.01-1.21]; p = 0.04) independent of age and body mass index.

CONCLUSION

Assessment of TIMP-2 and IGFBP7 within six hours after surgery appeared effective at predicting AKI in patients with LVADs. Larger studies are warranted to validate these findings.

De novo tacrolimus extended-release tablets (LCPT) versus twice-daily tacrolimus in adult heart transplantation: Results of a single-center non-inferiority matched control trial

Extended-release tacrolimus for prophylaxis of allograft rejection in orthotopic heart transplant (OHT) recipients is currently not FDA-approved. One such extended-release formulation of tacrolimus known as LCPT allows once-daily dosing and improves bioavailability compared to immediate-release tacrolimus (IR-tacrolimus). We compared the efficacy and safety of LCPT to IR-tacrolimus applied de novo in adult OHT recipients. Twenty-five prospective recipients on LCPT at our center from 2017 to 2019 were matched 1:2 with historical control recipients treated with IR-tacrolimus based on age, gender, and baseline creatinine. The primary composite outcome of death, acute cellular rejection, and/or new graft dysfunction within 1 year was compared using non-inferiority analysis. LCPT demonstrated non-inferiority to IR-tacrolimus, with a primary outcome risk reduction of 20% (90% CI: -40%, -.5%; non-inferiority P = .001). Tacrolimus trough levels peaked at 2-3 months and were higher in LCPT (median 14.5 vs. 12.7 ng/ml; P = .03) with similar dose levels (LCPT vs. IR-tacrolimus: .08 vs. .09 mg/kg/day; P = .33). Cardiovascular-related readmissions were reduced by 62% (P = .046) in LCPT patients. The complication rate per transplant admission and all-cause readmission rate did not differ significantly. These results suggest that LCPT is non-inferior in efficacy to IR-tacrolimus with a similar safety profile and improved bioavailability in OHT.

Impact of risk-stratified mycophenolate dosing in heart transplantation

Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid, is a highly effective immunosuppressive agent in heart transplant therapy. While the FDA approved dose is 1500 mg twice daily, dosing is often reduced due to dose-dependent adverse effects. However, empiric MMF dose reductions may lead to sub-therapeutic dosing and impair clinical outcomes. Our single center protocolized a risk-stratified approach based on age and weight to dose 500 mg twice daily or 1000 mg twice daily to patients after heart transplantation. This retrospective single-center study analyzed 140 consecutive heart transplant patients who were initiated on our risk-stratified MMF protocol post-transplant. The analysis revealed that the composite rate of biopsy-proven rejection, graft loss, or mortality at 1-year post-transplantation was similar between the two groups. Incidence of neutropenia, thrombocytopenia, infection, cardiac allograft vasculopathy, or acute kidney injury by 1-year also showed similar results between the two groups. Risk-stratification of MMF dosing appears to be a safe and effective strategy after heart transplantation.