Impact of carfilzomib-based desensitization on heart transplantation of sensitized candidates.

BACKGROUND: Allosensitization in heart transplant candidates is associated with longer transplant wait times and post-transplant complications. We summarize our experience with desensitization using carfilzomib, an irreversible proteasome inhibitor that causes plasma cell apoptosis. METHODS: One cycle of desensitization consisted of plasmapheresis and carfilzomib 20 mg/m2 on days 1, 2, 8, 9, 15, and 16 with intravenous immune globulin 2 g/kg after carfilzomib on day 16. Patients underwent repeat cycles as indicated. We compare calculated panel-reactive antibody (cPRA) for neat combined Class I and II IgG and C1q pre- and post-treatment using a cutoff for cPRA entry of ≥ 4000 and 500 MFI, respectively. RESULTS: From June 2013 to October 2019, 9 patients underwent 20 cycles of carfilzomib-based desensitization. Each cycle resulted in an average cPRA decrease of 24% (95% CI: 6-42) for IgG and 36% (95% CI: 17-55) for C1q. From treatment start to finish, mean cPRA fell from 76% to 40% (p = 0.01) for IgG and 56% to 4% (p = 0.017) for C1q. Six of 9 patients have been transplanted with 5 of the transplanted hearts crossing preoperative donor-specific antibodies. During a median follow-up of 35.1 months, all transplanted patients have survived with only 1 occurrence of treated rejection. Side effects of desensitization included acute kidney injury (67%) and thrombocytopenia (33%) with all episodes self-resolving. CONCLUSIONS: A carfilzomib-based desensitization strategy among heart transplant candidates reduces the level of HLA antibodies and complement binding, facilitates successful transplantation, and is associated with excellent outcomes at 3 years.

Ethical considerations regarding heart and lung transplantation and mechanical circulatory support during the COVID-19 pandemic: an ISHLT COVID-19 Task Force statement.

To understand the challenges for thoracic transplantation and mechanical circulatory support during the current coronavirus disease 2019 pandemic, we propose separating the effects of the pandemic into 5 distinct stages from a healthcare system perspective. We discuss how the classical ethical principles of utility, justice, and efficiency may need to be adapted, and we give specific recommendations for thoracic transplantation and mechanical circulatory support centers to balance their clinical decisions and strategies for advanced heart and lung disease during the current pandemic.

Gene expression profiling and racial disparities in outcomes after heart transplantation.

BACKGROUND: African Americans (AAs) have lower survival rates after heart transplantation (HTx) than Caucasians. The aim of this analysis was to evaluate racial differences in gene expression and their associations with survival and the composite outcome of death, retransplant, rejection with hemodynamic compromise, and graft dysfunction in the Outcomes AlloMap Registry. METHODS: Registry participants included low-risk Caucasian and AA heart transplant recipients with a baseline and at least 1 follow-up gene expression test (AlloMap(C)) within the first year after HTx. The Kaplan-Meier method with delayed entry was used to describe differences in outcomes. Multivariable Cox hazard regression was used to evaluate the associations of overall gene expression profiling score, MARCH8 and FLT3 expression, and tacrolimus levels with each outcome, and stratified Cox models were developed to quantify race-specific associations. RESULTS: Among 933 eligible recipients, 737 (79%) were Caucasian and 196 (21%) were AA. Compared with Caucasians, AAs were significantly younger (55 vs 59 years, p < 0.001), with higher rates of non-ischemic cardiomyopathy (68% vs 50%, p < 0.001), sensitization (>10% panel reactive antibody, 16% vs 9.1%, p = 0.009), and human leukocyte antigen mismatches (7 vs 7, p = 0.01), but less frequent primary cytomegalovirus serostatus mismatch (14.31% vs 27.3%, p < 0.001). Overall, AAs had an increased adjusted mortality risk (hazard ratio [HR] 4.13, p = 0.007). Higher tacrolimus levels were associated with decreased mortality in AAs (HR 0.62, p = 0.009). Overall gene expression profiling score was associated with increased mortality among Caucasians (HR 1.21, p = 0.048). In Caucasians, but not AAs, overexpression of MARCH8 was associated with increased mortality (HR 2.90, p = 0.001). FLT3 upregulation was associated with increased mortality (HR 2.42, p = 0.033) in AAs. There was an inverse relationship between FLT3 expression and tacrolimus levels (-0.029 and -0.176, respectively) in Caucasians and AAs. CONCLUSIONS: AAs have a significantly higher mortality risk after HTx than Caucasians, even in the low-risk Outcomes AlloMap Registry population. AAs and Caucasians had differential outcomes based upon the varying expression of MARCH8 and FLT3 genes following HTx.

Infectious complications after heart transplantation in patients screened with gene expression profiling.

BACKGROUND: The risk of infection after heart transplantation is highest within the first year and represents the leading cause of early mortality. In this cohort of patients enrolled in the Outcomes AlloMap Registry (OAR), we sought to describe infection episodes (IEp) resulting in hospitalization, in the early (<1 year) and late (≥1 year) post-transplant period and determine the impact of immunosuppression on incidence of infection. METHODS: The primary aim was to assess the incidence and nature of IEp. The secondary aim was to evaluate the effect of potential risk factors, such as recipient age; sex; body mass index; panel-reactive antibodies; cytomegalovirus (CMV) primary mismatch; prednisone, tacrolimus, and sirolimus levels; and gene expression profile (GEP) score, in the development of IEp. RESULTS: The OAR comprises 1,504 patients, of whom 220 patients (14.6%) had an IEp during a median follow-up period of 382 days (interquartile range [IQR] 230 to 579 days). The cause-specific 5-year hazard ratio for any infection was 2.029 (p = 0.12). The pattern of early infection was consistent with nosocomial and opportunistic causes, whereas later infection was consistent with late-onset opportunistic and community-acquired etiologies. Sixty-two percent of the infections occurred early. In the time-dependent analysis, higher prednisone dose (log prednisone, hazard ratio [HR] 1.30, p = 0.022) was the most significant risk factor for all IEp. CONCLUSIONS: In the OAR cohort, the majority of infections occurred within 1 year after transplantation. Clinicians may consider more aggressive prednisone withdrawal in low-risk patients to reduce IEp.

Risk evaluation using gene expression screening to monitor for acute cellular rejection in heart transplant recipients.

BACKGROUND: Gene expression profiling (GEP) was developed for non-invasive surveillance of acute cellular rejection. Despite its widespread use, there has been a paucity in outcome data for patients managed with GEP outside of clinical trials. METHODS: The Outcomes AlloMap Registry (OAR) is an observational, prospective, multicenter study including patients aged ≥ 15 years and ≥ 55 days post-cardiac transplant. Primary outcome was death and a composite outcome of hemodynamically significant rejection, graft dysfunction, retransplantation, or death. Secondary outcomes included readmission rates and development of coronary allograft vasculopathy and malignancies. RESULTS: The study included 1,504 patients, who were predominantly Caucasian (69%), male (74%), and aged 54.1 ± 12.9 years. The prevalence of moderate to severe acute cellular rejection (≥2R) was 2.0% from 2 to 6 months and 2.2% after 6 months. In the OAR there was no association between higher GEP scores and coronary allograft vasculopathy (p = 0.25), cancer (p = 0.16), or non-cytomegalovirus infection (p = 0.10). Survival at 1, 2, and 5 years post-transplant was 99%, 98%, and 94%, respectively. The composite outcome occurred in 103 patients during the follow-up period. GEP scores in dual-organ recipients (heart-kidney and heart-liver) were comparable to heart-alone recipients. CONCLUSIONS: This registry comprises the largest contemporary cohort of patients undergoing GEP for surveillance. Among patients selected for GEP surveillance, survival is excellent, and rates of acute rejection, graft dysfunction, readmission, and death are low.

Substantial Reduction in Driveline Infection Rates With the Modification of Driveline Dressing Protocol.

BACKGROUND: Driveline infection (DLI) is a cause of morbidity and mortality in patients with continuous-flow left ventricular assist devices (CF-LVADs). We hypothesized that an alternate dressing protocol would decrease the rate of DLIs. METHODS AND RESULTS: A retrospective review of CF-LVAD implants at a single institution from January 2010 to October 2015 was conducted. Patients were divided into implants before (group 1) and after (group 2) the introduction of the new protocol on September 1, 2012. Patients were followed until death, transplantation, change in dressing type, or 2 years. 153 patients were included: 61 in group 1 and 92 in group 2. Group 1 had fewer HVADs than group 2 (27.9% vs 71.7%; P < .001) and more destination therapy, although the latter was not statistically significant (50.8% vs 34.8%; P = .118). At 24 months, the freedom from DLI was 53% in group 1 and 89% in group 2 (P = .01). Group 1 had a significantly greater risk of DLI than group 2 (incident rate ratio 3.18, 95% confidence interval 1.23-8.18; P = .016). CONCLUSIONS: Dramatic improvement in freedom from DLI at 2 years was achieved with a new driveline dressing protocol. This demonstrates that DLI rates can be improved with alternate percutaneous site care techniques in CF-LVAD patients.

Effects of Isavuconazole on the Plasma Concentrations of Tacrolimus among Solid-Organ Transplant Patients.

We evaluated the interaction between isavuconazole and tacrolimus among 55 organ transplant recipients. After isavuconazole discontinuation, the tacrolimus concentration/dose ratio normalized by weight (C/D) was reduced by 16%. Liver transplant recipients experienced the largest C/D reduction. A 1.3-fold decrease in tacrolimus daily dose was required to maintain desired tacrolimus levels. There was considerable interpatient variability in the magnitude of the drug interaction. Tacrolimus doses should not be adjusted uniformly but, rather, be guided by therapeutic drug monitoring.

Low vitamin D exposure is associated with higher risk of infection in renal transplant recipients.

BACKGROUND: Vitamin D is a steroid hormone with multiple vital roles within the immune system. Various studies evaluated the influence of vitamin D on infections postrenal transplantation and found contrasting results. This study aimed to assess the relationship between vitamin D status and the incidence of infection in renal transplant recipients. METHODS: This is a retrospective cohort study of adult renal transplant recipients at the University of Pittsburgh Medical Center between 2005 and 2012. Patients were grouped as vitamin D sufficient (≥30 ng/mL) or deficient (<30 ng/mL) based on total serum 25-hydroxyvitamin D concentrations. The association between vitamin D levels collected at any point post-transplantation and incidence of infection within ±90 days of the vitamin D levels were assessed using logistic and Poisson's regression models. RESULTS: Vitamin D sufficiency at any point post-transplantation was significantly associated with a 66% lower odds (OR: 0.34; 95% CI: 0.22-0.52; P<.001) and 43% lower rate of infections (incident rate ratio (IRR): 0.57; 95% CI: 0.46-0.71; P<.001) within ±90 days of the vitamin D level. Baseline vitamin D level was also associated with lower incidence and risk for infections within the first year post-transplantation. CONCLUSION: Adequate levels of vitamin D in kidney transplant recipients are associated with lower infection risk in the first year and at any time post-transplantation.

Evaluation of Direct Oral Anticoagulation Therapy in Heart and Lung Transplant Recipients.

CONTEXT: Anticoagulation therapy is common in thoracic transplant recipients. Direct oral anticoagulants (DOACs) are alternatives to warfarin therapy, but characterization of their use in solid organ transplant is absent. OBJECTIVE: The primary objective of this study was to describe a thoracic transplant patient population initiated on DOAC therapy. Secondary objectives were to assess adverse reactions, venous thromboembolism (VTE) recurrence, and drug-drug interactions during DOAC therapy. STUDY DESIGN: Single-center retrospective cohort study. SETTING: A tertiary care medical center including inpatient hospitalization and outpatient transplant clinic visits. PATIENTS: Thoracic transplant recipients who were initiated on DOACs between May 1, 2011, and March 1, 2015, at the University of Pittsburgh Medical Center were included. RESULTS: A total of 37 patients were included in the analysis. A majority of the patients were lung transplant recipients (86.4%) with a median age of 60.7 years. Twenty-eight patients had a history of VTE. The primary indication for DOAC initiation was VTE (86.5%). Rivaroxaban (78.4%) was the most commonly utilized agent. Dose reductions for major drug interactions (37.8%), renal insufficiency (10.8%), or both (8.1%) occurred within the study. Two patients had breakthrough VTE during DOAC therapy. Eight bleeding events were reported in the cohort, one of which was considered a major bleed. There was no difference in the incidence of bleeding in patients with drug-drug interactions and without drug-drug interactions during DOAC therapy (26.0% vs 7.1%, P = .154). CONCLUSION: Direct oral anticoagulant therapy was well tolerated by thoracic transplant recipients. Drug interactions and renal dose adjustments were common.

Assessing Anticoagulation Practice Patterns in Patients on Durable Mechanical Circulatory Support Devices: An International Survey.

Anticoagulation in mechanical circulatory support (MCS) patients dictated by local practice, and therefore uniform standards for management are lacking. To characterize the worldwide variance in anticoagulation and antiplatelet therapy in patients with MCS devices, a 42 item survey was created and distributed electronically in August 2014. The survey assessed the center-perceived thromboembolic risk (minimal, low, moderate, or high) and characterized the antiplatelet and anticoagulant strategies for the Thoratec HeartMate II (HMII) and HeartWare HVAD (HVAD). A total of 83/214 centers (39%) responded: North America (60/152), Europe (18/50), Australia (2/4), and Asia (3/8). Although the most common target international normalized ratio (INR) was 2-3 for both devices, significant variability exists. Anticoagulation intensity tended to be lower with the HMII, with more centers targeting INR values of less than 2.5. Aspirin monotherapy was the most common antiplatelet regimen; however, the HVAD patients were more likely to be on daily aspirin doses over 100 mg. In addition, parenteral bridging was more frequent with the HVAD device. While 43.8% of respondents indicated an increase in the perceived risk of HMII device thrombosis in 2014, intensification of anticoagulation (22%) or antiplatelet (11%) therapy was infrequent. Our findings verify the wide variety of anticoagulation practice patterns between MCS centers.

Cost-effectiveness of routine surveillance endomyocardial biopsy after 12 months post-heart transplantation.

BACKGROUND: Despite low risk of late rejection after heart transplant (HT), surveillance endomyocardial biopsies (EMBs) are often continued for years. We assessed the cost-effectiveness of routine EMB after 12 months post-HT. METHODS AND RESULTS: Markov model compared the following surveillance EMB strategies to baseline strategy of stopping EMB 12 months post-HT: (1) every 4 months during year 2 post-HT, (2) every 6 months during year 2, (3) every 4 months for years 2 to 3, and (4) every 6 months for years 2 to 3. Patients entered the model 12 months post-HT and were followed until 36 months. In all strategies, patients had EMB with symptoms; in biopsy strategies after 12 months, EMB was also performed as scheduled regardless of symptoms. One-way and Monte Carlo sensitivity analyses were performed. Stopping EMB at 12 months was dominant (more effective, less costly), saving $2884 per patient compared with the next best strategy (every 6 months for year 2) and gaining 0.0011 quality-adjusted life-years. Increasing the annual risk of asymptomatic rejection in years 2 to 3 from previously reported 2.5% to 8.5% resulted in the biopsy every 6 months for year 2 strategy gaining 0.0006 quality-adjusted life-years, but cost $4 913 599 per quality-adjusted life-year gained. EMB for 12 months was also no longer dominant when mortality risk from untreated asymptomatic rejection approached 11%; competing strategies still cost >$200 000 per quality-adjusted life-year as that risk approached 99%. CONCLUSIONS: Surveillance EMB for 12 months post-HT is more effective and less costly than EMB performed after 12 months, unless risks of asymptomatic cellular rejection and its mortality are strikingly higher than previously observed.

Blood pressure control in continuous flow left ventricular assist devices: efficacy and impact on adverse events.

BACKGROUND: Continuous flow (CF) left ventricular assist devices (LVAD) are afterload sensitive and therefore pump performance is affected by hypertension. In addition, poorly controlled hypertension may increase the risk of aortic insufficiency (AI) and stroke. Blood pressure regimens after CF LVAD have not been studied and their impact on rates of AI and stroke are unknown. METHODS: Patients who had CF LVAD at a single center and were supported greater than 30 days were included. Blood pressure was monitored at home by Doppler. Outpatient management of blood pressure was conducted according to a predefined institutional protocol (target mean arterial pressure ≤ 80 mm Hg). RESULTS: A total of 96 patients were included. At the end of follow-up, 25 patients were not on an antihypertensive drug, of these 9 died. Of the 74% receiving antihypertensives, 54% required 1 medication, 34% were on 2, 10% were on 3, and 3% were on 4 or more. Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (85% of patients on an antihypertensive) and beta blockers (30%) were the most commonly prescribed medications. There was a significantly higher neurologic event rate in those on no antihypertensives compared with those on antihypertensives (p = 0.009). Only 3% of patients with no or mild AI at baseline progressed to develop moderate or greater AI after a mean of 201 days of follow-up. CONCLUSIONS: Blood pressure control can be achieved in patients with CF LVADs, with the majority of patients requiring only 1 or 2 antihypertensives.

Optical coherence tomography for characterization of cardiac allograft vasculopathy after heart transplantation (OCTCAV study).

BACKGROUND: Optical coherence tomography (OCT) is a novel intravascular imaging modality with excellent spatial resolution. This study explored the utility of OCT in cardiac transplantation for the detection and characterization of early changes associated with coronary allograft vasculopathy (CAV). METHODS: Fifteen consecutive patients, 1 to 4 years after transplant with no angiographic evidence of CAV, underwent successful OCT imaging using the Fourier-domain OCT system (C7-XR, St. Jude Medical, St. Paul, MN) in the left anterior descending artery. Analysis included measurements of the lumen, intima, and media layers, and characterization of atherosclerotic plaques. Patients were stratified by intima-to-media (I/M) ratio and classified as normal (≤1) or abnormal (>1). RESULTS: Patients were a mean of 2.8 years after transplant, 58 years old, and 92% were men. OCT imaging revealed 8 of 15 patients had intimal hyperplasia with an I/M ratio >1. Comparing those with I/M ratio of ≤1 and >1, the median (interquartile range) intimal thickness was greater (75 [70-101] vs 206 [97-269]µm, p = 0.03), whereas the media thickness was no different (72 [70-103] vs 94 [73-113]µm, p = 0.53). In addition, 7 of 15 patients had lipid-rich or calcified atherosclerotic plaques. CONCLUSIONS: OCT provides high-resolution quantitative imaging of the coronary arteries and its use allows for detailed assessment of the coronary artery wall and early morphologic changes that occur after cardiac transplantation. The clinical predictive value of these OCT-derived measurements remains to be determined.

Alemtuzumab for cytolytic induction of immunosuppression in heart transplant recipients.

OBJECTIVE: To review available evidence about the safety and efficacy of alemtuzumab for induction of immunosuppression in heart transplant recipients. DATA SOURCES: Searches of MEDLINE, EMBASE, and Cochrane databases were conducted. Key search terms included alemtuzumab, Campath-1H, CD52, lymphocyte, cytolytic, induction, immunosuppression, rejection, and cardiac transplantation. Additional pertinent data were identified through a search of abstracts from major transplant meetings. STUDY SELECTION AND DATA EXTRACTION: All English-language articles and abstracts identified from the data sources were evaluated. All primary data were eligible for inclusion if they evaluated the safety or efficacy of alemtuzumab for induction of immunosuppression in heart transplant patients. One retrospective cohort, 1 case series, 1 case-control series, and 1 open-label trial were identified and included for review. DATA SYNTHESIS: Acute cellular rejection occurs in 40% to 70% of heart transplant recipients within the first 6 months after transplant and is associated with significant morbidity and mortality. Depleting and nondepleting antibodies have displayed positive outcomes in inducing immunosuppression; however, the ideal induction strategy that balances efficacy and toxicity remains elusive. Alemtuzumab, a cytolytic anti-CD52 antibody, has been used to induce immunosuppression in kidney, pancreas, liver, intestine, and lung transplant recipients, and its use in heart transplant has been investigated. Studies of use of alemtuzumab to induce immunosuppression in heart transplant patients have shown low rates of rejection; however, it has not been directly compared with other immunosuppression-inducing agents and safety data are limited. CONCLUSIONS: Although alemtuzumab may be a practical option for inducing immunosuppression, data are insufficient to recommend its routine use in deference to more established agents. Large, randomized clinical trials with extended durations of follow-up must be conducted to characterize its efficacy and safety further.

Invasive aspergillosis among heart transplant recipients is rare but causes rapid death due to septic shock and multiple organ dysfunction syndrome.

Between 2000 and 2011, proven or probable invasive aspergillosis (IA) was diagnosed in 1.7% (8/455) of heart transplant (HTx) recipients at our center, in the absence of antifungal prophylaxis. All patients had invasive pulmonary infections and 75% (6/8) were diagnosed during 2 separate 3-month periods. Cases were notable for their association with septic shock and multiple organ dysfunction syndrome (MODS) (75%, 6/8 each), non-specific clinical and radiographic findings, and rapid mortality despite mould-active antifungal therapy (88%, 7/8; occuring at a median 11 days after diagnosis). All patients had predisposing conditions known to be risk factors for IA. For patients with early IA (within 90 days of HTx), conditions included hemodialysis, thoracic re-operation, and the presence of another case in the institution within the preceding 3 months. For late-onset IA, conditions included hemodialysis and receipt of augmented immunosuppression. Clinicians should suspect IA in HTx recipients with risk factors who present with non-specific and unexplained respiratory syndromes, including those in septic shock and MODS, and institute prompt antifungal therapy without waiting for the results of cultures or other diagnostic tests.

Long-term effects on renal function of dose-reduced calcineurin inhibitor and sirolimus in cardiac transplant patients.

UNLABELLED: Calcineurin inhibitor (CNI)-associated renal insufficiency is common after cardiac transplantation (CTX); however, the addition of sirolimus allows for CNI dose reduction and this strategy may limit CNI renal toxicity. This study examines the long-term effects of such a strategy. METHODS: Patients from a single center who had CTX from 1990 to 2007 and who were converted to sirolimus and a dose-reduced CNI were compared to group-matched controls maintained on CNI and an antiproliferative agent. RESULTS: One hundred and fifty-five patients (79 sirolimus and 76 controls) were included and had similar baseline characteristics. Sirolimus was started a mean of 1429 d post-CTX and maintained for a mean of 823 d. Reason for conversion to sirolimus was renal insufficiency (34%), vasculopathy (29%), recurrent rejection (19%), and other (18%). The eGFR was not different between groups at baseline (44.7 mL/min/1.73 m(2) vs. 46.0, p = 0.64) or at any point during follow-up: 90 d, 180 d, 1 yr, 2 yr, and 3 yr. conclusion: Patients converted to a regimen of sirolimus and a dosed-reduced CNI have stable renal function over the following three yr, but do not have an improvement in renal outcomes compared to patients maintained on full dose CNI.

Generic maintenance immunosuppression in solid organ transplant recipients.

Survival after solid organ transplantation has increased in the era of tacrolimus and mycophenolate. This increased survival could be due in part to the broad clinical use of these potent and specific agents for maintenance immunosuppression. These drugs have enhanced specificity and potency for T and B lymphocytes compared with their predecessors, cyclosporine and azathioprine. Between 2008 and 2010, the United States Food and Drug Administration approved several generic formulations of both tacrolimus and mycophenolate mofetil. Deciding whether generic products can be safely substituted for the innovator product is a clinical dilemma similar to that which occurred when generic formulations of cyclosporine became available. We describe the concerns regarding generic immunosuppression use, summarize expert opinion and consensus statements in transplantation, analyze the potential impact of generic substitution, and provide estimates of populations affected based on generic drug market penetration. Formulary considerations such as cost, availability, and potential drug ordering and drug selection errors are described, and transplant coordinator and patient perspectives are reviewed. Finally, general recommendations about the use of generic maintenance immunosuppression in solid organ transplant recipients are provided. Although more research is needed to confirm clinical and therapeutic equivalence and pharmacoeconomic benefit, generic immunosuppressants can be safely substituted for innovator products as long as patients consistently receive the same product, patients and clinicians are aware of when substitutions occur, and enhanced therapeutic drug monitoring is provided during the transition.