Apixaban as an alternative to warfarin for patients with a left ventricular assist device

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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.

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.

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.

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.

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.

Elevated tacrolimus levels associated with intravenous azithromycin and ceftriaxone: a case report

Drug interactions are a common occurrence with calcineurin inhibitors. We describe the case of a heart transplant recipient who developed increased tacrolimus blood levels after the administration of intravenous azithromycin and ceftriaxone. Tacrolimus levels decreased after the discontinuation of ceftriaxone and switch from intravenous to oral azithromycin. Transplant recipients who receive intravenous azithromycin and/or ceftriaxone concomitantly with tacrolimus therapy should be monitored closely for the duration of the antibiotic administration.

Alemtuzumab induction prior to cardiac transplantation with lower intensity maintenance immunosuppression: one-year outcomes

Induction therapy with alemtuzumab (C-1H) prior to cardiac transplantation (CTX) may allow for lower intensity maintenance immunosuppression. This is a retrospective study of patients who underwent CTX at a single institution from January 2001 until April 2009 and received no induction versus induction with C-1H on a background of tacrolimus and mycophenolate. Those with C-1H received dose-reduced calcineurin inhibitor and no steroids. A total of 220 patients were included, 110 received C-1H and 110 received no induction. Recipient baseline characteristics, donor age and gender were not different between the two groups. Mean tacrolimus levels (ng/mL) for C-1H versus no induction: months 1-3 (8.5 vs. 12.9), month 4-6 (10.2 vs. 13.0), month 7-9 (10.2 vs. 11.9) and month 10-12 (9.9 vs. 11.3) were all significantly lower for the C-1H group, p < 0.001. There were no differences between the C-1H and no induction groups at 12 months for overall survival 85.1% versus 93.6% p = 0.09, but freedom from significant rejection was significantly higher for the C-1H group, 84.5% versus 51.6%, p < 0.0001. In conclusion, induction therapy after CTX with C-1H results in a similar 12 month survival, but a greater freedom from rejection despite lower calcineurin levels and without the use of steroids.

Tacrolimus and Lopinavir/Ritonavir Interaction in Liver Transplantation

OBJECTIVE

To report an interaction between tacrolimus and the protease inhibitor combination lopinavir/ritonavir in a liver transplant patient.

CASE SUMMARY

A 48-year-old white male liver transplant recipient receiving tacrolimus 5 mg twice daily for immunosuppression started highly active antiretroviral therapy for his HIV-positive status. Three days after initiation of lopinavir/ritonavir, the tacrolimus concentration rose sharply to toxic levels. Subsequent tacrolimus doses were withheld until tacrolimus concentrations normalized over 15 days. The tacrolimus dose was reestablished at a much lower dose, 0.5 mg once weekly. An objective causality assessment revealed that the adverse event was highly probable.

DISCUSSION

Tacrolimus is metabolized in the liver via CYP3A4. Protease inhibitors are known to inhibit CYP3A4 and have been documented to increase tacrolimus concentrations, putting the patient at risk of developing nephrotoxic and/or neurotoxic symptoms. In this case, concomitant use of lopinavir/ritonavir caused tacrolimus concentrations to rise more dramatically than had been previously reported in the literature for other protease inhibitors.

CONCLUSIONS

Extreme caution must be used when administering tacrolimus concomitantly with lopinavir/ritonavir. Therapeutic concentrations of tacrolimus can be maintained with tacrolimus doses that are far below standard dosages.

Limited tolerability of levofloxacin and pyrazinamide for multidrug-resistant tuberculosis prophylaxis in a solid organ transplant population

STUDY OBJECTIVE

To determine the long-term tolerability of prophylactic administration of pyrazinamide and levofloxacin in patients possibly exposed to multidrug-resistant tuberculosis (MDRTB) after undergoing solid organ transplantation.

DESIGN

Retrospective analysis.

SETTING

Community outpatient clinic.

PATIENTS

Forty-eight recipients of solid organ transplants beginning prophylaxis for MDRTB during August 1999 after possible exposure to a single index case of multidrug-resistant Mycobacterium tuberculosis within our community

INTERVENTION

Prophylaxis consisted of pyrazinamide 30 mg/kg/day plus levofloxacin 500 mg/day, administered for 1 year.

MEASUREMENTS AND MAIN RESULTS

Thirteen (27.1%) of the 48 patients completed therapy; 27 (56.3%) discontinued therapy within 4 months due to adverse drug events. Gastrointestinal intolerance was the major adverse event resulting in early discontinuation.

CONCLUSION

Prophylaxis of MDRTB with levofloxacin and pyrazinamide was associated with limited tolerability due to the high frequency of adverse events. While we search for a better tolerated prophylactic regimen, close monitoring for adverse reactions is recommended.

Hemorrhagic complications of enoxaparin and aspirin in patients with kidney transplants

STUDY OBJECTIVE

To evaluate the frequency of early posttransplant hemorrhagic complications in patients with kidney and kidney-pancreas transplants who received thromboprophylaxis with enoxaparin and aspirin.

DESIGN

Retrospective chart review.

SETTING

University-based tertiary care center.

PATIENTS

Thirteen patients who had received enoxaparin within 10 days of kidney or kidney-pancreas transplantation.

INTERVENTION

Medical records were reviewed, and data from patients who had received low-dose aspirin 81 mg once/day and enoxaparin within 10 days of transplantation were collected.

MEASUREMENTS AND MAIN RESULTS

Major bleeding events were defined as intracranial or retroperitoneal bleeding, or a decrease in hemoglobin of greater than 2 g/dl that was confirmed on repeat evaluation. Nine (69%) of the 13 patients had confirmed major bleeding events and required blood transfusions. Six of the nine patients had elevated serum creatinine levels.

CONCLUSION

The combination of enoxaparin and low-dose aspirin early after kidney or kidney-pancreas transplantation was associated with a high frequency of hemorrhagic events. Further evaluation is needed to determine the safety of enoxaparin in combination with aspirin after transplantation.