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U.S. Department of Health and Human Services

Post-Approval Studies (PAS)

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The FDA has the authority to require sponsors to perform a post-approval study (or studies) at the time of approval of a premarket approval (PMA), humanitarian device exemption (HDE), or product development protocol (PDP) application. Post-approval studies can provide patients, health care professionals, the device industry, the FDA and other stakeholders information on the continued safety and effectiveness (or continued probable benefit, in the case of an HDE) of approved medical devices. This database allows you to search Post-Approval Study information by applicant or device information.

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TRYTON Side Branch Stent EA Confirmatory

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Study Status Completed
Application Number P150039 / PAS002
Date Current Protocol Accepted  
Study Name TRYTON Side Branch Stent EA Confirmatory
General Study Protocol Parameters
Study Design Prospective Cohort Study
Data Source New Data Collection
Comparison Group Objective Performance Criterion
Analysis Type Analytical
Study Population Adult: >21
Detailed Study Protocol Parameters
Study Design Description TRYTON Extended Access (EA) Confirmatory Study - a non-randomized, single arm extension of the TRYTON Pivotal RCT. Subjects were implanted with the TRYTON Side Branch Stent with main branch approved DES for treatment of native coronary artery bifurcation disease.

Study Population Description N = 133 TRYTON patients
Sample Size 127 subjects yields 90% power to reject the following null hypothesis in favor of the corresponding alternative hypothesis:

• H0: pTRY greater than or equal to 0.179 (or 17.9%)

• H1: pTRY less than 0.179 (or 17.9%)

Where pTRY is the primary endpoint rate in the DES+TRYTON. Six additional subjects to be enrolled to account for an expected 4% loss to follow-up before the primary endpoint was measured, so the total enrolled sample size was planned to be 133. Enrolling 127 subjects affords 90% power to compare the primary endpoint rate from the EA Study to a performance goal of 17.9%, assuming a true endpoint rate of 8.9% for DES+TRYTON.

Data Collection Primary endpoint: Periprocedural MI defined as PCI CK-MB elevation with value >3 times the upper range limit within the first 48 hours after PCI.

Key secondary endpoints included all-cause mortality, Major Adverse Cardiac Events (MACE), and rates of stent thrombosis using the ARC definition.

Follow-up Visits and Length of Follow-up 1 year post-index procedure

Interim or Final Data Summary
Actual Number of Patients Enrolled 133 subjects
Actual Number of Sites Enrolled 28 sites
Patient Follow-up Rate All patients were scheduled to return for clinical follow-up assessments at 30 days and 12 months post-index procedure.
Final Safety Findings The EA Confirmatory Study provided additional procedural safety data on the TRYTON Side Branch Stent. There were three (3) primary goals of the study: (1) Confirm the ability of physicians to enroll patients with appropriately-sized side branch diameters to accommodate the TRYTON Stent; (2) Confirm the acute safety profile of the TRYTON Stent (consistent with the post hoc analysis of the pivotal RCT Intended Population of patients with a QCA assessed side branch RVD greater than or equal to 2.25 mm) by demonstrating an acceptable periprocedural MI rate; and (3) Confirm the other clinical outcomes observed in the Pivotal RCT Intended Population. The key study results are as follows:

Treatment with TRYTON Side Branch Stent met its primary endpoint with an observed periprocedural MI (PPMI) rate of 10.5%, which supports the acute safety profile of the TRYTON Stent seen in the TRYTON Pivotal RCT post hoc analysis of the Intended Population.

Physicians were able to select patients with appropriately sized side branches (RVD greater than or equal to 2.5 mm (greater than or equal to 2.25 mm by QCA, the Intended Population) in 99.2% (132/133) of subjects.

Final Effect Findings In the EA Confirmatory Study, the TVR rate was 9.6% (12/125) at 1-year, which was numerically higher than the TVR rate of 9.3% (32/343) in the Tryton Stent ITT subjects in the Pivotal RCT at 1-year and 6.3% (9/142) in the Intended Population (side branch RVD greater than or equal to 2.25 mm) Pivotal RCT subjects at 1-year. However, conclusions based on these data are limited by small sample sizes.
Study Strengths & Weaknesses Operators were successful in selecting 99.2% (132/133) of bifurcation lesions with appropriately sized side branches (greater than or equal to 2.25 mm in diameter by QCA).
Recommendations for Labeling Changes The sponsor will be requested to add the complete 12-month follow-up data to the labeling.

TRYTON Side Branch Stent EA Confirmatory Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
Final Report 08/22/2017 06/01/2017 On Time

Contact Us

Julie Unger
Project Manager, Post-Approval Studies Program
Food and Drug Administration
10903 New Hampshire Ave
WO66-4206v Silver Spring, MD

Phone: (301) 796-6134
Fax: (301) 847-8140

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