Cardiac allograft vasculopathy and survival in pediatric heart transplant recipients transitioned to adult care.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is an important cause of mortality after pediatric heart transplantation (HT) but there is a paucity of data regarding its incidence and impact on survival in pediatric recipients transitioned to adult care. METHODS: We conducted a retrospective review of consecutive pediatric HT patients from 1989 to 2017 at the Hospital for Sick Children who transitioned to adult care at ≥18 years at Toronto General Hospital. We evaluated the incidence of International Society of Heart and Lung Transplantation CAV grade ≥1 using competing risk models. We assessed the association between all-cause mortality and CAV using Cox proportional hazards and used Kaplan Meier methods to evaluate all-cause mortality stratified by CAV and transplant era (1989-2001, 2002-2017). RESULTS: Ninety-six patients were transitioned to adult care by January 2022, of which 53 underwent repeat coronary angiography as adults. CAV was newly diagnosed in 49% patients after transition to adult care. The overall incidence of CAV was 3.9 cases per 100 person-years. There was no difference in the adjusted incidence of CAV according to transplant era (subdistribution hazard ratios = 1.17, 95% confidence interval (CI) 0.54-2.66). CAV was associated with a higher risk of death in the early era (hazard ratio (HR) 10.29, 95% CI 2.16-49.96), but not in the recent era (HR 1.61, 95% 0.35-7.47). CONCLUSIONS: There is a role for continued CAV surveillance after the transition to adult care. The implications of diagnosing CAV after the transition to adult care require further study, particularly because the risk of death in pediatric HT recipients diagnosed with CAV in the more recent era may be attenuated compared to the earlier HT era.

Predicted heart mass for size matching in obese heart transplant donors and recipients.

INTRODUCTION: Predicted heart mass (PHM) was neither derived nor evaluated in an obese population. Our objective was to evaluate size mismatch using actual body weight or ideal body weight (IBW)-adjusted PHM on mortality and risk assessment. METHODS: We conducted a retrospective cohort study of adult recipients with BMI ≥30 kg/m2 or recipients of donors with BMI≥30 kg/m2 from the ISHLT registry. We used multivariable Cox proportional hazard models to evaluate 30-day and 1-year mortality. The two models were compared using net reclassification index. RESULTS: 10,817 HT recipients, age 55 (IQR 46-62) years, 23% female, BMI 31 kg/m2 (IQR 28-33) were included. Donors were age 34 (IQR 24-44) years, 31% female, and BMI 31 kg/m2 (IQR 26-34). There was a significant nonlinear association between mortality and actual PHM but not IBW-adjusted PHM. Undersizing using actual PHM was associated with higher 30-day and 1-year mortality (p < .01), not seen with IBW-adjusted PHM. Actual PHM better risk classified .6% (95% CI .3-.8) patients compared to IBW-adjusted PHM. CONCLUSION: Actual PHM can be used for size matching when assessing mortality risk in obese recipients or recipients of obese donors. There is no advantage to re-calculating PHM using IBW to define candidate risk at the time of organ allocation.

Remote Mobile Outpatient Monitoring in Transplant (Reboot) 2.0: Protocol for a Randomized Controlled Trial.

BACKGROUND: The number of solid organ transplants in Canada has increased 33% over the past decade. Hospital readmissions are common within the first year after transplant and are linked to increased morbidity and mortality. Nearly half of these admissions to the hospital appear to be preventable. Mobile health (mHealth) technologies hold promise to reduce admission to the hospital and improve patient outcomes, as they allow real-time monitoring and timely clinical intervention. OBJECTIVE: This study aims to determine whether an innovative mHealth intervention can reduce hospital readmission and unscheduled visits to the emergency department or transplant clinic. Our second objective is to assess the use of clinical and continuous ambulatory physiologic data to develop machine learning algorithms to predict the risk of infection, organ rejection, and early mortality in adult heart, kidney, and liver transplant recipients. METHODS: Remote Mobile Outpatient Monitoring in Transplant (Reboot) 2.0 is a two-phased single-center study to be conducted at the University Health Network in Toronto, Canada. Phase one will consist of a 1-year concealed randomized controlled trial of 400 adult heart, kidney, and liver transplant recipients. Participants will be randomized to receive either personalized communication using an mHealth app in addition to standard of care phone communication (intervention group) or standard of care communication only (control group). In phase two, the prior collected data set will be used to develop machine learning algorithms to identify early markers of rejection, infection, and graft dysfunction posttransplantation. The primary outcome will be a composite of any unscheduled hospital admission, visits to the emergency department or transplant clinic, following discharge from the index admission. Secondary outcomes will include patient-reported outcomes using validated self-administered questionnaires, 1-year graft survival rate, 1-year patient survival rate, and the number of standard of care phone voice messages. RESULTS: At the time of this paper's completion, no results are available. CONCLUSIONS: Building from previous work, this project will aim to leverage an innovative mHealth app to improve outcomes and reduce hospital readmission in adult solid organ transplant recipients. Additionally, the development of machine learning algorithms to better predict adverse health outcomes will allow for personalized medicine to tailor clinician-patient interactions and mitigate the health care burden of a growing patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT04721288; https://www.clinicaltrials.gov/ct2/show/NCT04721288. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/26816.

Incidence and impact of primary graft dysfunction in adult heart transplant recipients: A systematic review and meta-analysis.

PURPOSE: Primary graft dysfunction (PGD) is a leading cause of early mortality after heart transplant (HTx). To identify PGD incidence and impact on mortality, and to elucidate risk factors for PGD, we systematically reviewed studies using the ISHLT 2014 Consensus Report definition and reporting the incidence of PGD in adult HTx recipients. METHODS: We conducted a systematic search in January 2020 including studies reporting the incidence of PGD in adult HTx recipients. We used a random effects model to pool the incidence of PGD among HTx recipients and, for each PGD severity, the mortality rate among those who developed PGD. For prognostic factors evaluated in ≥2 studies, we used random effects meta-analyses to pool the adjusted odds ratios for development of PGD. The GRADE framework informed our certainty in the evidence. RESULTS: Of 148 publications identified, 36 observational studies proved eligible. With moderate certainty, we observed pooled incidences of 3.5%, 6.6%, 7.7%, and 1.6% and 1-year mortality rates of 15%, 21%, 41%, and 35% for mild, moderate, severe and isolated right ventricular-PGD, respectively. Donor factors (female sex, and undersized), recipient factors (creatinine, and pre-HTx use of amiodarone, and temporary or durable mechanical support), and prolonged ischemic time proved associated with PGD post-HTx. CONCLUSION: Our review suggests that the incidence of PGD may be low but its risk of mortality high, increasing with PGD severity. Prognostic factors, including undersized donor, recipient use of amiodarone pre-HTx and recipient creatinine may guide future studies in exploring donor and/or recipient selection and risk mitigation strategies.

The Resilience of Cardiac Care Through Virtualized Services During the COVID-19 Pandemic: Case Study of a Heart Function Clinic.

BACKGROUND: Virtual care has historically faced barriers to widespread adoption. However, the COVID-19 pandemic has necessitated the rapid adoption and expansion of virtual care technologies. Although the intense and prolonged nature of the COVID-19 pandemic has renewed people's interest in health systems resilience, which includes how services adapt or transform in response to shocks, evidence regarding the role of virtual care technologies in health systems resilience is scarce. OBJECTIVE: At Toronto General Hospital in Ontario, Canada, the rapid virtualization of cardiac care began on March 9, 2020, as a response to the pandemic. The objective of this study was to understand people's experiences with and the barriers and facilitators of the rapid virtualization and expansion of cardiac care resulting from the pandemic. METHODS: A single-case study was conducted with 3 embedded units of analysis. Patients, clinicians, and staff were recruited purposively from an existing mobile, phone-based telemonitoring program at a heart function clinic in Toronto, Canada. Individual, semistructured phone interviews were conducted by two researchers and transcribed verbatim. An inductive thematic analysis at the semantic level was used to analyze transcripts and develop themes. RESULTS: A total of 29 participants were interviewed, including patients (n=16), clinicians (n=9), and staff (n=4). The following five themes were identified: (1) patient safety as a catalyst for virtual care adoption; (2) piecemeal virtual care solutions; (3) confronting new roles and workloads; (4) missing pieces in virtual care; and (5) the inequity paradox. The motivation to protect patient safety and a piecemeal approach to virtual care adoption facilitated the absorptive and adaptive resilience of cardiac care during the COVID-19 pandemic. However, ad hoc changes to clinic roles and workflows, challenges in building relationships through remote methods, and widened inequities were barriers that threatened virtual care sustainment. CONCLUSIONS: We contend that sustaining virtual care hinges upon transformative actions (rather than adaptive actions) that strengthen health systems so that they can face the dynamic and emergent challenges associated with COVID-19 and other shocks. Based on the barriers and facilitators we identified, we present the lessons we learned and recommend transformations for sustaining virtual care during and beyond the COVID-19 pandemic.

Left Ventricular Assist Device Support for Fabry Cardiomyopathy: A Case Series.

Patients with restrictive cardiomyopathy due to Fabry disease are often deemed ineligible for left ventricular assist device (LVAD) support due to the risk of suction events with a small LV cavity. We describe the first case series of LVAD support for Fabry disease. LVAD therapy can improve survival, quality of life, and provide clinical stability to start enzyme replacement therapy. Precautions at the time of surgery include rapid treatment of fever to avoid Fabry crises, involvement of a multidisciplinary team, and early initiation of rehabilitation. We describe LVAD support for both bridging and destination therapy.

Les patients qui ont une cardiomyopathie restrictive due à la maladie de Fabry sont souvent considérés non admissibles aux dispositifs d'assistance ventriculaire gauche (DAVG) en raison du risque de succion lié à la petite cavité VG. Nous décrivons la première série de cas liée aux DAVG en présence de la maladie de Fabry. La thérapie par DAVG peut contribuer à l'amélioration de la survie, de la qualité de vie et offrir une stabilité clinique pour débuter l'enzymothérapie de substitution. Parmi les précautions à prendre au moment de l'intervention chirurgicale figurent le traitement rapide de la fièvre pour éviter les crises de Fabry, la participation de l'équipe multidisciplinaire et la mise en place précoce de la réadaptation. Nous décrivons l'utilisation du DAVG à titre de pont jusqu'à la transplantation et à titre de thérapie définitive.

Predicting Survival After VA-ECMO for Refractory Cardiogenic Shock: Validating the SAVE Score.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is used increasingly to support patients who are in cardiogenic shock. Due to the risk of complications, prediction models may aid in identifying patients who would benefit most from VA-ECMO. One such model is the Survival After Veno-Arterial Extracorporeal Membrane Oxygenation (SAVE) score. Therefore, we wanted to validate the utility of the SAVE score in a contemporary cohort of adult patients. METHODS: Retrospective data were extracted from electronic health records of 120 patients with cardiogenic shock supported with VA-ECMO between 2011 and 2018. The SAVE score was calculated for each patient to predict survival to hospital discharge. We assessed the SAVE score calibration by comparing predicted vs observed survival at discharge. We assessed discrimination with the area under the receiver operating curve using logistic regression. RESULTS: A total of 45% of patients survived to hospital discharge. Survivors had a significantly higher mean SAVE score (-9.3 ± 4.1 in survivors vs -13.1 ± 4.4, respectively; P = 0.001). SAVE score discrimination was adequate (c = 0.77; 95% confidence interval 0.69-0.86; P < 0.001). SAVE score calibration was limited, as observed survival rates for risk classes II-V were higher in our cohort (II: 67% vs 58%; III: 78% vs 42%; IV: 61% vs 30%; and V: 29% vs 18%). CONCLUSIONS: The SAVE score underestimates survival in a contemporary North American cohort of adult patients with cardiogenic shock. Its inaccurate performance could lead to denying ECMO support to patients deemed to be too high risk. Further studies are needed to validate additional predictive models for patients requiring VA-ECMO.

CONTEXTE: L'oxygénation extracorporelle veino-artérielle (ECMO-VA) est de plus en plus utilisée comme assistance pour les patients qui sont en choc cardiogène. En raison du risque de complications, des modèles de prédiction peuvent aider à déterminer quels patients bénéficieraient le plus d'une ECMO-VA. Le score SAVE (Survival After Veno-Arterial Extracorporeal Membrane Oxygenation) est un modèle de ce genre. Par conséquent, nous voulions valider l'utilité du score SAVE dans une cohorte contemporaine de patients adultes. MÉTHODOLOGIE: Des données rétrospectives ont été extraites de dossiers médicaux électroniques de 120 patients atteints d'un choc cardiogène ayant reçu une ECMO-VA entre 2011 et 2018. Le score SAVE a été calculé pour chaque patient afin de prédire la survie au congé de l'hôpital. Nous avons évalué la calibration du score SAVE en comparant la survie prédite au moment du congé et la survie observée. Nous avons évalué la discrimination par l'aire sous la courbe opérationnelle chez le receveur en faisant appel à la régression logistique. RÉSULTATS: Au total, 45 % des patients ont survécu au congé de l'hôpital. Les survivants affichaient un score SAVE moyen considérablement plus élevé (­9,3 ± 4,1 chez les survivants vs ­13,1 ± 4,4; p = 0,001). La discrimination par le score SAVE était adéquate (c = 0,77; intervalle de confiance à 95 % : 0,69 à 0,86; p < 0,001). La calibration du score SAVE était limitée, car les taux pour les classes de risque II à V étaient plus élevés dans notre cohorte (II : 67 % vs 58 %; III : 78 % vs 42 %; IV : 61 % vs 30 %; et V : 29 % vs 18 %). CONCLUSIONS: Le score SAVE sous-estime la survie dans une cohorte nord-américaine contemporaine de patients adultes atteints d'un choc cardiogène. L'inexactitude de ses résultats pourrait faire en sorte qu'une assistance par ECMO serait refusée à des patients jugés comme présentant un risque élevé. D'autres études sont nécessaires pour valider d'autres modèles de prédiction pour les patients ayant besoin d'une ECMO-VA.

Improving the design of heart failure care from the perspective of frontline providers and administrators: A qualitative case study of a large, urban health system.

BACKGROUND: Heart failure patients often present with frailty and/or multi-morbidity, complicating care and service delivery. The Chronic Care Model (CCM) is a useful framework for designing care for complex patients. It assumes responsibility of several actors, including frontline providers and health-care administrators, in creating conditions for optimal chronic care management. This qualitative case study examines perceptions of care among providers and administrators in a large, urban health system in Canada, and how the CCM might inform redesign of care to improve health system functioning. METHODS: Sixteen semi-structured interviews were conducted between August 2014 and January 2016. Interpretive analysis was conducted to identify how informants perceive care among this population and the extent to which the design of heart failure care aligns with elements of the CCM. RESULTS: Current care approaches could better align with CCM elements. Key changes to improve health system functioning for complex heart failure patients that align with the CCM include closing knowledge gaps, standardizing treatment, improving interdisciplinary communication and improving patient care pathways following hospital discharge. CONCLUSIONS: The CCM can be used to guide health system design and interventions for frail and multi-morbid heart failure patients. Addressing care- and service-delivery barriers has important clinical, administrative and economic implications.