Noninvasive Physiologic Assessment of Cardiac Allograft Vasculopathy Is Prognostic for Post-Transplant Events.

BACKGROUND: Cardiac allograft vasculopathy (CAV) causes impaired blood flow in both epicardial coronary arteries and the microvasculature. A leading cause of post-transplant mortality, CAV affects 50% of heart transplant recipients within 10 years of heart transplant. OBJECTIVES: This analysis examined the outcomes of heart transplant recipients with reduced myocardial blood flow reserve (MBFR) and microvascular CAV detected by 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging. METHODS: A total of 181 heart transplant recipients who underwent PET to assess for CAV were included with a median follow-up of 4.7 years. Patients were classified into 2 groups according to the total MBFR: >2.0 and ≤2.0. Microvascular CAV was defined as no epicardial CAV detected by PET and/or coronary angiography, but with an MBFR ≤2.0 by PET. RESULTS: In total, 71 (39%) patients had an MBFR ≤2.0. Patients with an MBFR ≤2.0 experienced an increased risk for all outcomes: 7-fold increase in death or retransplantation (HR: 7.05; 95% CI: 3.2-15.6; P < 0.0001), 12-fold increase in cardiovascular death (HR: 12.0; 95% CI: 2.64-54.12; P = 0.001), and 10-fold increase in cardiovascular hospitalization (HR: 10.1; 95% CI: 3.43-29.9; P < 0.0001). The 5-year mean survival was 302 days less than those with an MBFR >2.0 (95% CI: 260.2-345.4 days; P < 0.0001). Microvascular CAV (adjusted HR: 3.86; 95% CI: 1.58-9.40; P = 0.003) was independently associated with an increased risk of death or retransplantation. CONCLUSIONS: Abnormal myocardial blood flow reserve, even in the absence of epicardial CAV, identifies patients at a high risk of death or retransplantation. Measures of myocardial blood flow provide prognostic information in addition to traditional CAV assessment.

Evolving Characteristics of Heart Transplantation Donors and Recipients: JACC Focus Seminar.

Although the burden of end-stage heart failure continues to increase, the number of available organs for heart transplantation (HT) remains inadequate. The HT community has been challenged to find ways to expand the number of donor hearts available. Recent advances include use of hearts from donors infected with hepatitis C virus as well as other previously underutilized donors, including those with left ventricular dysfunction, of older age, and with a history of cocaine use. Concurrently, emerging trends in HT surgery include donation after circulatory death, ex vivo normothermic heart perfusion, and controlled hypothermic preservation, which may enable procurement of organs from farther distances and prevent early allograft dysfunction. Contemporary HT recipients have also evolved in light of the 2018 revision to the U.S. heart allocation policy. This focus seminar discusses recent trends in donor and recipient phenotypes and management strategies for successful HT, as well as evolving areas and future directions.

Outcomes of COVID-19 in solid organ transplant recipients: A matched cohort study.

Whether solid organ transplant (SOT) recipients are at increased risk of poor outcomes due to COVID-19 in comparison to the general population remains uncertain. In this study, we compared outcomes of SOT recipients and non-SOT patients hospitalized with COVID-19 in a propensity score matched analysis based on age, race, ethnicity, BMI, diabetes, and hypertension. After propensity matching, 117 SOT recipients and 350 non-SOT patients were evaluated. The median age of SOT recipients was 61 years, with a median time from transplant of 5.68 years. The most common transplanted organs were kidney (48%), followed by lung (21%), heart (19%), and liver (10%). Overall, SOT recipients were more likely to receive COVID-19 specific therapies and to require ICU admission. However, mortality (23.08% in SOT recipients vs. 23.14% in controls, P = .21) and highest level of supplemental oxygen (P = .32) required during hospitalization did not significantly differ between groups. In this propensity matched cohort study, SOT recipients hospitalized with COVID-19 had similar overall outcomes as non-SOT recipients, suggesting that chronic immunosuppression may not be an independent risk factor for poor outcomes in COVID-19.

Prevalence and predictors of SARS-CoV-2 antibodies among solid organ transplant recipients with confirmed infection.

It remains uncertain whether immunocompromised patients including solid organ transplant (SOT) recipients will have a robust antibody response to SARS-CoV-2 infection. We enrolled all adult SOT recipients at our center with confirmed SARS-CoV-2 infection who underwent antibody testing with a single commercially available anti-nucleocapsid antibody test at least 7 days after diagnosis in a retrospective cohort. Seventy SOT recipients were studied (56% kidney, 19% lung, 14% liver ± kidney, and 11% heart ± kidney recipients). Thirty-six (51%) had positive anti-nucleocapsid antibody testing, and 34 (49%) were negative. Recipients of a kidney allograft were less likely to have positive antibody testing compared to those who did not receive a kidney (p = .04). In the final multivariable model, the years from transplant to diagnosis (OR 1.26, p = .002) and baseline immunosuppression with more than two agents (OR 0.26, p = .03) were significantly associated with the antibody test result, controlling for kidney transplantation. In conclusion, among SOT recipients with confirmed infection, only 51% of patients had detectable anti-nucleocapsid antibodies, and transplant-related variables including the level and nature of immunosuppression were important predictors. These findings raise the concern that SOT recipients with COVID-19 may be less likely to form SARS-CoV-2 antibodies.

Tocilizumab for severe COVID-19 in solid organ transplant recipients: a matched cohort study.

The safety and efficacy of tocilizumab for the treatment of severe respiratory symptoms due to COVID-19 remain uncertain, in particular among solid organ transplant (SOT) recipients. Thus, we evaluated the clinical characteristics and outcomes of 29 hospitalized SOT recipients who received tocilizumab for severe COVID-19, compared to a matched control group who did not. Among a total of 117 total SOT recipients hospitalized with COVID-19, 29 (24.8%) received tocilizumab. The 90-day mortality was significantly higher among patients who received tocilizumab (41%) compared to those who did not (20%, P = .03). When compared to control patients matched by age, hypertension, chronic kidney disease, and administration of high dose corticosteroids, there was no significant difference in mortality (41% vs 28%, P = .27), hospital discharge (52% vs 72%, P = .26), or secondary infections (34% vs 24%, P = .55). Among patients who received tocilizumab, there was also no difference in mortality based on the level of oxygen support (intubated vs not intubated) at the time of tocilizumab initiation. In this matched cohort study, tocilizumab appeared to be safe but was not associated with decreased 90-day mortality. Larger randomized studies are needed to identify whether there are subsets of SOT recipients who may benefit from tocilizumab for treatment of COVID-19.

Transition of a Large Tertiary Heart Failure Program in Response to the COVID-19 Pandemic: Changes That Will Endure.

The coronavirus disease 2019 (COVID-19) pandemic imposed severe restrictions on traditional methods of patient care. During the pandemic, the heart failure program at New York-Presbyterian Hospital in New York, NY rapidly and comprehensively transitioned its care delivery model and administrative organization to conform to a new healthcare environment while still providing high-quality care to a large cohort of patients with heart failure, heart transplantation, and left ventricular assist device. In addition to the widespread adoption of telehealth, our program restructured outpatient care, initiating a shared clinic model and introducing a comprehensive remote monitoring program to manage patients with heart failure and heart transplant. All conferences, including administrative meetings, support groups, and educational seminars were converted to teleconferencing platforms. Following the peak of COVID-19, many of the new changes have been maintained, and the program structure will be permanently altered as a lasting effect of this pandemic. In this article, we review the details of our program's transition in the face of COVID-19 and highlight the programmatic changes that will endure.

Trends in US Heart Transplant Waitlist Activity and Volume During the Coronavirus Disease 2019 (COVID-19) Pandemic.

IMPORTANCE: Solid organ transplants have declined significantly during the coronavirus disease (COVID-19) pandemic in the US. Limited data exist regarding changes in heart transplant (HT). OBJECTIVE: To describe national and regional trends in waitlist inactivations, waitlist additions, donor recovery, and HT volume during COVID-19. DESIGN, SETTING, AND PARTICIPANTS: This descriptive cross-sectional study used publicly available data from the United Network for Organ Sharing and US Centers for Disease Control and Prevention, using 8 prespecified United Network for Organ Sharing regions. Adult (18 years or older) HT candidates listed and deceased donors recovered between January 19 to May 9, 2020. EXPOSURES: COVID-19 pandemic. MAIN OUTCOMES AND MEASURES: Changes in waitlist inactivations, waitlist additions, deceased donor recovery, and transplant volumes from the pre-COVID-19 (January 19-March 15, 2020) to the COVID-19 era (March 15-May 9, 2020). Density mapping and linear regression with interrupted time series analysis were used to characterize changes over time and changes by region. RESULTS: During the COVID-19 era, there were 600 waitlist inactivations compared with 343 during the pre-COVID era (75% increase). Waitlist additions decreased from 637 to 395 (37% reduction). These changes were most profound in the Northeast and Great Lakes regions with high rates of COVID-19. Deceased donor recovery decreased by 26% from 1878 to 1395; the most significant decrease occurred in the North Midwest despite low COVID-19 prevalence. Heart transplant volumes were significantly reduced across all regions except the Northwest. The largest decrease was seen in the Northeast where COVID-19 case rates were highest. From the pre-COVID-19 era to the COVID-19 era, there was significant regional variation in waitlist additions (eg, 69% decrease in the Northeast vs 8.5% increase in the South Midwest; P < .001) and deceased donor recovery (eg, 41% decrease in North Midwest vs 16% decrease in South Midwest; P = .02). CONCLUSIONS AND RELEVANCE: Heart transplant volumes have been significantly reduced in recent months, even in regions with a lower prevalence of COVID-19 cases. This has been accompanied by increased waitlist inactivations, decreased waitlist additions, and decreased donor recovery. Future studies are needed to determine if the COVID-19 pandemic is associated with changes in waitlist mortality.

Characteristics and Outcomes of Recipients of Heart Transplant With Coronavirus Disease 2019.

Importance: Recipients of heart transplant (HT) may be at increased risk of adverse outcomes attributable to infection with coronavirus disease 2019 (COVID-19) because of multiple comorbidities and clinically significant immunosuppression. Objective: To describe the characteristics, treatment, and outcomes of recipients of HT with COVID-19. Design, Setting, and Participants: This case series from a single large academic heart transplant program in New York, New York, incorporates data from between March 1, 2020, and April 24, 2020. All recipients of HT followed up by this center who were infected with COVID-19 were included. Interventions: Heart transplant and a confirmed diagnosis of COVID-19. Main Outcomes and Measures: The primary measure was vital status at end of study follow-up. Secondary measures included patient characteristics, laboratory analyses, changes to immunosuppression, and treatment administered for COVID-19. Results: Twenty-eight patients with HT received a confirmed diagnosis of COVID-19. The median age was 64.0 (interquartile range [IQR], 53.5-70.5) years, 22 (79%) were men, and the median time from HT was 8.6 (IQR, 4.2-14.5) years. Comorbid conditions included hypertension in 20 patients (71%), diabetes in 17 patients (61%), and cardiac allograft vasculopathy in 16 patients (57%). Twenty-two participants (79%) were admitted for treatment, and 7 (25%) required mechanical ventilation. Most (13 of 17 [76%]) had evidence of myocardial injury (median high-sensitivity troponin T, 0.055 [IQR, 0.0205-0.1345] ng/mL) and elevated inflammatory biomarkers (median peak high-sensitivity C-reactive protein, 11.83 [IQR, 7.44-19.26] mg/dL; median peak interleukin 6, 105 [IQR, 38-296] pg/mL). Among patients managed at the study institution, mycophenolate mofetil was discontinued in 16 patients (70%), and 6 (26%) had a reduction in the dose of their calcineurin inhibitor. Treatment of COVID-19 included hydroxychloroquine (18 patients [78%]), high-dose corticosteroids (8 patients [47%]), and interleukin 6 receptor antagonists (6 patients [26%]). Overall, 7 patients (25%) died. Among 22 patients (79%) who were admitted, 11 (50%) were discharged home, 4 (18%) remain hospitalized at the end of the study, and 7 (32%) died during hospitalization. Conclusions and Relevance: In this single-center case series, COVID-19 infection was associated with a case fatality rate of 25% in recipients of HT. Immunosuppression was reduced in most of this group of patients. Further study is required to evaluate the optimal approach to management of COVID-19 infection in the HT population.

COVID-19 in solid organ transplant recipients: Initial report from the US epicenter.

Solid organ transplant recipients may be at a high risk for SARS-CoV-2 infection and poor associated outcomes. We herein report our initial experience with solid organ transplant recipients with SARS-CoV-2 infection at two centers during the first 3 weeks of the outbreak in New York City. Baseline characteristics, clinical presentation, antiviral and immunosuppressive management were compared between patients with mild/moderate and severe disease (defined as ICU admission, intubation or death). Ninety patients were analyzed with a median age of 57 years. Forty-six were kidney recipients, 17 lung, 13 liver, 9 heart, and 5 dual-organ transplants. The most common presenting symptoms were fever (70%), cough (59%), and dyspnea (43%). Twenty-two (24%) had mild, 41 (46%) moderate, and 27 (30%) severe disease. Among the 68 hospitalized patients, 12% required non-rebreather and 35% required intubation. 91% received hydroxychloroquine, 66% azithromycin, 3% remdesivir, 21% tocilizumab, and 24% bolus steroids. Sixteen patients died (18% overall, 24% of hospitalized, 52% of ICU) and 37 (54%) were discharged. In this initial cohort, transplant recipients with COVID-19 appear to have more severe outcomes, although testing limitations likely led to undercounting of mild/asymptomatic cases. As this outbreak unfolds, COVID-19 has the potential to severely impact solid organ transplant recipients.