The VANGUARD study is an open-label, prospective, randomized trial comparing the long-term outcomes of two advanced bioprosthetic aortic valves, Dafodil® and INSPIRIS Resilia®, in patients undergoing aortic valve replacement (AVR). This study aims to provide robust data on valve durability, safety, and hemodynamic performance, particularly in younger patients who may require multiple interventions over their lifetimes.

This single-center, prospective open-label randomized clinical trial will enroll 200 patients indicated for aortic native valve or prosthetic valve replacement. Participants will be randomly assigned in a 1:1 ratio to receive the Dafodil® or INSPIRIS Resilia® prosthesis. The trial will be conducted at a leading tertiary cardiology hospital within the Brazilian Unified Health System (SUS). The study is sponsored by Instituto Dante Pazzanese de Cardiologia and Fundação Adib Jatene, with device supply supported by Meril Life Sciences (Vapi, Gujarat, India) and Edwards Lifesciences (Irvine, CA, USA).

Screening and Recruitment Process Participants will be identified through in-hospital referrals and outpatient clinics. The screening process will involve a comprehensive review of medical histories, imaging studies (e.g., echocardiograms), and relevant laboratory tests. To ensure a representative sample and minimize selection bias, the study will actively recruit patients with diverse comorbidities and histories of prior surgical procedures.

Informed Consent Process The informed consent process will adhere to stringent ethical standards, ensuring that participants fully understand the purpose, procedures, potential risks, and benefits of the study. The trained study personnel will provide detailed explanations and answer any questions. Patients will be informed of their right to withdraw from the study at any time without impacting their standard of care. Consent will be documented according to institutional guidelines.

Randomization and Blinding Participants will be randomized in a 1:1 ratio using the RedCap system , a secure web-based platform specifically designed for clinical trials. The randomization sequence will be generated using permuted blocks of varying sizes to maintain allocation concealment and ensure a balanced distribution across treatment groups.

Although the study is open-label due to the inherent nature of the surgical procedures, several strategies will be implemented to minimize bias:

• Outcome Adjudication and Imaging Assessment: Assessors responsible for evaluating postoperative echocardiographic imaging results and adjudicators of clinical outcomes will remain blinded to treatment allocation, thereby reducing the risk of observer bias.
• Centralized Data Monitoring: An independent team, blinded to treatment assignments, will conduct centralized data monitoring during audits and interim analyses, further safeguarding the study's integrity.
• Objective Outcome Measures: The study will prioritize objective measures, such as hemodynamic parameters and imaging findings, to minimize the potential influence of subjective bias.

Interventions Surgical Procedure: Surgical aortic valve replacement (SAVR) will be performed following standardized protocols to ensure consistency and optimize patient outcomes. Under general anesthesia, a median sternotomy will be conducted to access the aorta. Cardiopulmonary bypass (CPB) will be initiated, and the aorta will be cross-clamped to facilitate the safe removal of the existing prosthesis. After excising the deteriorated valve and removing any calcification, the new bioprosthetic valve-either Dafodil® or INSPIRIS Resilia®-will be implanted. Transesophageal echocardiography (TEE) will be utilized to assess valve function prior to weaning the patient off CPB. The procedure will conclude with the closure of the sternum and the patients transfer to the intensive care unit (ICU) for postoperative monitoring.

Postoperative Care: All patients will receive standardized postoperative care, encompassing anticoagulation management, pain control, and vigilant monitoring for potential complications. Follow-up assessments will include routine imaging and clinical evaluations to monitor recovery and verify the proper function of the implanted prosthesis. These evaluations will be scheduled at predetermined intervals to ensure timely detection and management of any issues that may arise.

Follow-up Schedule Participants will undergo follow-up evaluations at 30 days, 3 months, and annually for up to 10 years post-surgery. Each visit will encompass comprehensive data collection, including medical history updates, current medications, laboratory test results, electrocardiograms (ECGs), and echocardiograms. This structured follow-up schedule is designed to monitor patient recovery, assess the functionality of the implanted prosthesis, and promptly identify any emerging complications.

Inclusion Criteria:

• Age: 18 to 65 years.
• Eligible for surgical replacement of native valve or re-replacement of a prosthetic valve with a bioprosthetic valve in the aortic position.

Exclusion Criteria:

• Indicated for mechanical prosthetic valve replacement.
• Require surgical intervention in another heart valve or transcatheter valve therapy.

IPD (Individual Patient Data) may not be shared due to concerns about patient confidentiality and data protection. Sharing such sensitive information could expose personal details and potentially violate privacy regulations. Additionally, there may be concerns about the misuse of data or its impact on the individuals privacy. Ensuring secure and ethical handling of IPD is crucial to protect patient rights and maintain trust.