Antagonization of Heparin With Protamine Sulfate After TAVI (ATLANTIS-Prota)

Antagonization of Heparin With Protamine Sulfate to Lower All Neurological Ischemic and Hemorrhagic Events After Transcatheter Aortic Valve Implantation for Aortic Stenosis

Transcatheter aortic valve replacement (TAVR) is now the first therapeutic option offered to high and intermediate risk patients with symptomatic aortic stenosis but even to low-risk, when the aortic valve is tricuspid and the transfemoral approach is suitable. Vascular and bleeding complications are the most frequent procedure-related unwanted events associated with increased short-term morbidity and mortality. Selection of the appropriate vascular access site and pre-closing devices as well as stent implantation mitigate these complications.

ACT-guided heparin reaching a target of 300 seconds or more is recommended prior to the placement of the guiding sheath in the common femoral artery. Protamine sulfate is the heparin antidote, which antagonizes 100% of its anti-IIa activity and 60% of its anti-Xa activity. Reversal of heparin using protamine sulfate is recommended for transapical and complicated transfemoral aortic valve placement.However, there is a great heterogeneity of protamine use in daily practice and supportive evidence for the prevention of bleeding complications as well as its safety is lacking. In addition, the radial approach for the second vascular access is more commonly used as well as the use of echo-guided femoral puncture further questioning reversal of heparin when the procedure has been successfully completed without overt bleeding complications.

Our study aims to demonstrate the superiority of a strategy of systematic ACT-guided heparin administration followed by systematic antagonization with protamine sulfate over usual of care to reduce in-hospital mortality, vascular/bleeding complications, stroke and transcient ischemic attack, myocardial infarction or red blood cell transfusion, from randomization to hospital discharge

Study Overview

• Status: Recruiting
• Conditions: Aortic Valve Stenosis; Heart Valve Diseases
• Intervention / Treatment: Drug: Antagonization of heparin with protamine sulfate

• Study Type: Interventional
• Enrollment (Estimated): 940
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Paul Dr GUEDENEY, MD; Phone Number: +33 0184827619; Email: paul.guedeney@aphp.fr

Study Locations

• France
  • Ile De France
    • Paris, Ile De France, France, 75013
      • Recruiting
      • Pitié Salpêtrière hospital
      • Contact: Paul GUEDENEY, MD, PHD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Men and women ≥18 years of age
• Any patient eligible for transfemoral TAVI, irrespective of the chronic antithrombotic treatment
• Written informed consent
• Registered at the French social healthcare

Exclusion Criteria:

• Any major protamine sulfate exposure contraindications defined as a history of severe pulmonary hypertension, acute pulmonary edema or history of bronchospasm related to protamine sulfate administration
• Known allergy to protamine sulfate
• Hypersensitivity to protamine sulfate including protamine contained as an excipient in NPH [Neutral Protamine Hagedorn] insulin, known protamine or protamine-heparine complex antibodies
• Non-femoral approach for the TAVI procedure
• Protamine sulfate exposure within 24h of randomization
• Fish allergy
• Mechanical valves
• For men: Sterile or Vasectomy
• Women of childbearing potential
• Pregnancy and breast feeding women
• Contemporaneous enrolment in an interventional clinical trial
• Patient under guardianship or curatorship

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Systematic heparine antagonization with protamine sulphate; Complete reversal of the Heparin administered during the TAVI achieved through the infusion of a protamine solution until the ACT returns to its baseline level.	Drug: Antagonization of heparin with protamine sulfate; A systematic use at the end of procedure of Protamine Sulfate for antagonization of heparine.1 mg of protamine sulfate neutralizes approximately 100 heparin unit. To be administered in slow infusion (10 min) not exceeding 50mg of protamine sulfate to reverse 100% of the anti-IIa activity of heparin sodium. If the ACT is not back to the baseline value after the end of this infusion, additional doses of protamine should be performed depending on the ACT value to obtain complete antagonization of anti-IIa activity of heparin sodium
No Intervention: No Systematic heparine antagonization with protamine sulphate; No administration of protamine solution unless a participant encounters a bleeding event requiring a surgery or percutanous intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite of ischemic and bleeding events	The primary endpoint is defined as the first occurrence, of any event of the composite of all-cause mortality, type 2, 3 or 4 bleeding, major or minor vascular complications, stroke or TIA, myocardial infarction or any redblood transfusion. The primary endpoint will be blindly determined by a clinical event committee according to the valve Academic Research Consortium-3 (VARC-3 classifications)	From procedure to hospital discharge (or at 30 days whichever comes first)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
In hospital stay	Assessment of length of in-hospital stay in days post TAVI procedure	From procedure to hospital discharge, assessed up to 30 days
Bleeding complication	Assessment of the occurrence of: Type 2, 3 or 4 bleeding according to the VARC 3 criteria or any red blood cell transfusion of minor or vascular complications.; Type 2, 3 or 4 bleedings or red blood cell transfusion.; Any red blood cell transfusion; Type 2, 3 or 4 bleedings	From procedure to hospital discharge (or at 30 days whichever comes first)
Assessement of interaction	Assessment of an interaction in the impact of systematic antagonization according to the use or not of an echo-guided femoral puncture and/or arterial radial access. These subgroups are defined at the time of randomization by stratification.	From procedure to hospital discharge (or at 30 days whichever comes first)
Assessement of adverse outcome	Assessment of the occurrence of: Death or type 2, 3 or 4 bleedings; Any kidney injury, stage 2 to 4 according to the KDIGO definition; Death, type 2, 3 or 4 bleedings or stroke; Death, VARC 3 type 2-3-4 bleeding or Any red blood cell transfusion, MI or stroke Or TIA; Any myocardial infarction, stroke or TIA; Type 3 or 4 bleeding; Type 2 bleeding; Minor vascular complications; Access site and access related vascular injury according to VARC-3 criteria	From procedure to hospital discharge (or at 30 days whichever comes first)
Assessement of long term adverse outcome	Assessment of the composite of: Death, stroke, TIA, MI and bleeding VARC type 2 or more as well as each individual endpoint	From procedure 12 months post procedure

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Collaborators: Action Research Group

Study record dates

Study Major Dates

• Study Start (Actual): May 25, 2025
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: December 22, 2023
• First Submitted That Met QC Criteria: January 10, 2024
• First Posted (Actual): January 22, 2024

Study Record Updates

• Last Update Posted (Actual): August 22, 2025
• Last Update Submitted That Met QC Criteria: August 18, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Protamine; TAVI; Aortic stenosis; Heparine; Antagonization
• Additional Relevant MeSH Terms: Aortic Valve Disease; Cardiovascular Diseases; Pathological Conditions, Anatomical; Heart Diseases; Ventricular Outflow Obstruction; Aortic Valve Stenosis; Constriction, Pathologic; Heart Valve Diseases; Molecular Mechanisms of Pharmacological Action; Fibrin Modulating Agents; Coagulants; Fibrinolytic Agents; Anticoagulants; Heparin Antagonists; Heparin; Protamines
• Other Study ID Numbers: APHP211046

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No