TORCH-LATAM: A Regional Pathway to Improve Transplant Evaluation for Congenital Heart Disease

TORCH-LATAM: A Pragmatic Stepped-Wedge Cluster-Randomized Effectiveness-Implementation Trial of an Integrated Regional Pathway for Heart, Lung, and Heart-Lung Transplant Access in Pediatric and Adult Congenital Heart Disease

Congenital heart disease can progress to advanced cardiac or cardiopulmonary failure requiring heart, heart-lung, or, in selected congenital conditions, bilateral lung transplantation with cardiac repair. Access to transplant evaluation and organ utilization can vary across regions and institutions, and potential candidates who are never referred or evaluated are not represented in conventional waiting-list statistics. TORCH-LATAM is a pragmatic multicenter stepped-wedge cluster-randomized effectiveness-implementation trial evaluating the TORCH Integrated Transplant Access Pathway (TORCH-ITAP) in Latin America. Regional network clusters transition in a randomized sequence from usual care to TORCH-ITAP. The pathway standardizes early identification and referral, a common recipient dataset, multidisciplinary candidacy adjudication, structured donor-organ assessment, immunologic and anatomic-physiologic matching, preservation and transport traceability, and navigation of clinical, regulatory, logistical, and financial barriers. The primary outcome is the proportion of enrolled recipient participants who complete a standardized multidisciplinary transplant evaluation and receive a documented candidacy decision within 90 days. Secondary outcomes include activation of an official transplant pathway or waitlist where applicable, transplantation within 12 months, pretransplant death or irreversible deterioration, donor-organ utilization, post-transplant safety and survival, and implementation outcomes. Recipient participants constitute the ClinicalTrials.gov enrollment; donors, organs, donor-recipient matches, preservation strategies, and transplant episodes are nested analytic units. TORCH-ITAP does not allocate organs and does not supersede national transplant laws, authorized transplant programs, or governmental requirements for cross-border organ movement.

TORCH-LATAM evaluates a regional health-services intervention for pediatric and adult participants with congenital heart disease who meet protocol-defined international triggers for transplant referral/evaluation or who already have documented transplant candidacy. The intervention begins before official waitlisting. It follows a traceable cascade from identification and screening through consent and enrollment, standardized multidisciplinary assessment, candidacy adjudication, activation of an authorized transplant pathway, donor-organ opportunity assessment, immunologic and anatomic-physiologic matching, procurement, preservation, transport, transplantation, and follow-up.

The unit of randomization is a TORCH Regional Network Cluster rather than an individual hospital. A cluster is a functional network anchored in an authorized transplant center and may include referral/evaluation sites, donor-origin hospitals, procurement or preservation functions, and regional data coordination. Clusters begin in usual care and transition at randomized prespecified steps to TORCH-ITAP; after transition they remain exposed to the intervention.

TORCH uses layered eligibility. Recipient eligibility is separate from donor-organ eligibility, immunologic compatibility, anatomic-physiologic matching, and final transplant-episode feasibility. Donation after brain death and donation after circulatory death are donation pathways and are not synonymous with extended-criteria donation. Procurement/reperfusion strategies, preservation technologies, infectious or malignancy transmission risk, and extended preservation/transport exposure are captured as separate dimensions. Preservation technologies are not randomized by the parent protocol unless a future prespecified substudy introduces randomized assignment.

The primary confirmatory analysis follows intention-to-treat according to randomized cluster-period assignment. The primary outcome is analyzed with a generalized linear mixed model including intervention and calendar period as fixed effects and cluster as a random effect. Time-to-transplant and pretransplant death or irreversible deterioration are analyzed using competing-risk/time-to-event methods. Donor-organ utilization and preservation analyses use nested multilevel or observational methods appropriate to their unit of analysis. Predictive modeling is exploratory and is separated from the confirmatory analysis.

The digital platform implements a version-controlled Common Data Model with role-based access, audit trails, timestamps, structured reasons for clinical and operational decisions, and interoperable data elements. Platform development and testing with synthetic or non-identifiable data may occur before participant enrollment and does not constitute the ClinicalTrials.gov Study Start Date.

TORCH-LATAM does not create an organ allocation authority. Official listing, organ allocation, procurement, transplantation, and any cross-border movement remain subject to applicable law, competent authorities, institutional authorization, informed consent, and traceability.

Inclusion Criteria:

• Confirmed congenital heart disease.
• Age from birth with no protocol-defined upper age limit.
• Advanced cardiac, pulmonary vascular, or cardiopulmonary deterioration meeting contemporary international criteria for transplant referral/evaluation, or previously documented transplant candidacy by an authorized program.
• Clinical presentation within the TORCH scope: heart transplantation; heart-lung transplantation; or, in selected congenital heart disease, bilateral lung transplantation with cardiac repair after multidisciplinary adjudication.
• Availability of the minimum baseline dataset required for standardized multidisciplinary evaluation and risk stratification.
• Written informed consent from the participant or legally authorized representative, with assent and re-consent as applicable under local requirements.
• Ability to undergo protocol-defined longitudinal follow-up.
• For participants referred from a non-transplant site, an operational referral route within the participating network to at least one authorized transplant center must exist. Prior acceptance by that transplant center is not required for trial enrollment; completion of specialist evaluation and the candidacy decision are post-enrollment trial processes/outcomes.

Exclusion Criteria:

• Absence of congenital heart disease or a transplant indication outside the TORCH congenital-heart-disease scope.
• No protocol-defined indication for transplant referral/evaluation after standardized review.
• A contemporary absolute contraindication to all transplant strategies applicable to the participant that is confirmed by multidisciplinary adjudication and is not considered reversible or re-evaluable under the protocol.
• Inability to obtain required informed consent/assent or to collect the minimum essential baseline dataset.
• A legal, regulatory, or safety condition that prohibits participation in research at the enrolling site.