Risk Stratification Post TAVI Using TEG (RISTRATAVI)

November 30, 2020 updated by: Torben Pottgiesser

Risk Stratification for Subclinical Leaflet Thrombosis Post TAVI Using Thromboelastography

Transcatheter aortic valve implantation (TAVI) has become the standard of care in elderly patients at increased risk for surgical aortic valve replacement . However, the optimal antithrombotic strategy post TAVI is still unclear. Current European guidelines recommend dual antiplatelet therapy (DAPT) for 3 to 6 months.The prevalence of subclinical leaflet thrombosis after TAVI is 15% up to 40%, but its clinical long-term relevance is uncertain. Thromboelastography (TEG(R)) can be used as a point-of-care system evaluating a patient's individual hemostasis profile. For the detection of transcatheter valve thrombosis it may be superior to conventional platelet function testing because global hemostasis can be assessed in addition to platelet function. The investigators intend an observational trial recruiting patients undergoing TAVI under standard care. At defined time points the investigators will serially perform TEG(R) as well as further platelet function testing (multiple electrode aggregometry) and conventional coagulation testing. The primary objective is to find surrogate TEG-derived markers / models predicting the development of a subclinical leaflet thrombosis after TAVI under usual care. The secondary objective is to find TEG-derived markers / models identifying patients at an increased risk after TAVI (all-cause mortality, cardiovascular mortality, thromboembolic and bleeding events).

Study Overview

Status

Recruiting

Conditions

Detailed Description

Aortic stenosis is the most common primary valve disease in high-income countries with increasing importance. Throughout the last 15 years, transcatheter aortic valve implantation (TAVI) has become an alternative to surgical aortic valve replacement, the former standard of care. Nowadays, the use of TAVI in elderly patients at increased surgical risk is favored. There is still an important lack of evidence concerning the optimal antithrombotic strategy post TAVI. Recently, it has been shown that the prevalence of subclinical leaflet thrombosis after intervention has been underestimated and may be present in around 15 % up to 40% (PORTICO IDE trial) of transcatheter valves. One study demonstrated that transient ischemic attacks are significantly increased in these patients.

European guidelines are undecided towards the length of the dual antiplatelet therapy (DAPT) after TAVI and recommend optional treatment durations between 3 to 6 months. The optimal duration of DAPT is not known, although DAPT duration is associated with an increased bleeding risk. The most recent update of AHA guidelines for valvular heart disease state that oral anticoagulation with a VKA (INR of 2.5) may be reasonable for at least 3 months after TAVI in patients at low risk of bleeding. Without favoring one over the other recommendation, the current AHA guidelines also maintain the prior statement (from 2014) that clopidogrel 75 mg daily may be reasonable for the first 6 months after TAVI in addition to life-long aspirin, which is in accordance with the European Guideline recommendation. On the other hand, the GALILEO trial has recently been stopped as patients receiving rivaroxaban after TAVI (no prior atrial fibrillation) had a higher mortality and thromboembolic events as well as higher bleeding event rates.

The TEG(R) 6S analyzer is a point-of-care system evaluating a patient's individual hemostasis profile by thrombelastography (TEG(R)), a potentially superior tool compared to conventional platelet function testing. The TEG(R) system has been able to predict thrombotic complications in different clinical contexts.

In classic coronary interventional cardiology, the strength of adenosine diphosphate (ADP)-induced and thrombin-induced platelet-fibrin clots were found to be indicators of long-term poststenting ischemic events. As the pathophysiologic mechanism of subclinical leaflet thrombosis has not been examined in detail, the investigators hypothesize that several TEG(R) assays may provide insight in finding predictive TEG(R) markers. Furthermore, as the onset of subclinical leaflet thrombosis is not clear and may possibly increase over time, the design with subsequent TEG(R) analyses at 3 timepoints (0, 3, 6 months) will help to hopefully identify predictors that may become evident at later time points.

It is intriguing to hypothesize that the better predictive marker may be found using the Global Hemostasis Assay. This is relevant as leaflet thrombosis develops despite dual antiplatelet therapy and anticoagulation has been shown to fully resolve subclinical leaflet thrombosis. The Global Hemostasis Assay may deliver prediction beyond platelet function, which may improve antithrombotic therapy post TAVI. Finding a predictive TEG marker (examining Platelet Mapping and Global Hemostasis together) holds the promise for future individualized clinical decision-making by identifying individual risk.

Taken together, we hope that individual TEG based stratification of patients at risk for subclinical leaflet thrombosis or other events may allow individual clinical decision-making.

Study Type

Observational

Enrollment (Anticipated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

50 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

All patients that are scheduled for TAVI using a commercially available valve after clinical decision making within the local Heart Team will be possible subjects yielding the eligibility criteria.

Description

Inclusion Criteria:

- Patients are eligible for enrollment if they are scheduled for TAVI using a commercially available valve after clinical decision making within the local Heart Team.

Exclusion Criteria:

  • Valve-in-valve TAVI and prior valve thrombosis
  • Severely impaired renal function (e.g. creatinine clearance < 30ml/min)
  • poor CT imaging if the presence of HALT cannot be assessed.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
TAVI and no therapeutic anticoagulation
Subjects in this group do not have an indication for therapeutic anticoagulation.
TAVI and therapeutic anticoagulation
Subjects in this group have an indication for therapeutic anticoagulation such as atrial fibrillation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Global TEG(R)-based prediction of hypoattenuating leaflet thickening (HALT)
Time Frame: 6 months
TEG(R)readout Global Hemostasis Assay
6 months
Platelet TEG(R)-based prediction of hypoattenuating leaflet thickening (HALT)
Time Frame: 6 months
TEG(R)readout Platelet Mapping Assay
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
All-cause mortality within 12 months
Time Frame: 12 months
All-cause mortality will be recorded within 12 months after TAVI.
12 months
Cardiovascular mortality within 12 months
Time Frame: 12 months
Cardiovascular mortality will be recorded within 12 months after TAVI.
12 months
Thromboembolic events within 12 months
Time Frame: 12 months
Thromboembolic events will be recorded within 12 months after TAVI.
12 months
Bleeding events within 12 months
Time Frame: 12 months
Bleeding events will be recorded within 12 months after TAVI.
12 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of hypoattenuating leaflet thickening (HALT)
Time Frame: 6 months
Presence of HALT on CT scan
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Torben Pottgiesser

Investigators

  • Principal Investigator: Torben Pottgiesser, MD, Cardiology and Angiology I, Heart Center Freiburg University, Germany
  • Study Director: Daniel Duerschmied, MD, Cardiology and Angiology I, Heart Center Freiburg University, Germany

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

October 1, 2020

Primary Completion (ANTICIPATED)

April 30, 2022

Study Completion (ANTICIPATED)

April 30, 2023

Study Registration Dates

First Submitted

August 10, 2018

First Submitted That Met QC Criteria

August 26, 2018

First Posted (ACTUAL)

August 28, 2018

Study Record Updates

Last Update Posted (ACTUAL)

December 1, 2020

Last Update Submitted That Met QC Criteria

November 30, 2020

Last Verified

November 1, 2020

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RISTRATAVI-1-2019

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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