In January 2005, the oversight responsibility of the Post-Approval Studies Program was transferred to the Division of Epidemiology (DEPI) of the Office of Surveillance and Biometrics (OSB)/Center for Devices and Radiological Health (CDRH).
The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a premarket approval (PMA) application, protocol development product (PDP) application, or humanitarian device exemption (HDE) application. The program helps ensure that well-designed post-approval studies (PAS) are conducted effectively and efficiently and in the least burdensome manner.
CDRH has established an automated, internal tracking system that efficiently identifies the reporting status of active PAS studies ordered since January 1, 2005 based on study timelines incorporated in study protocols and agreed upon by the CDRH and applicants. This system represents CDRH's effort to ensure that all PAS commitments are fulfilled in a timely manner.
In addition, CDRH launched this publicly available webpage to keep all stakeholders informed of the progress of each PAS. The webpage displays general information regarding each PAS, as well as the overall study status (based on protocol-driven timelines and the adequacy of the data) and the applicant's reporting status for each submission due.
The purpose of the MAVErIC Phase I and II studies was to demonstrate the safety
and efficacy of the Exponent Self-Expanding Carotid Stent System with the GuardWire Plus Temporary Occlusion and Aspiration System for the treatment of carotid stenosis. A Supplement (S059) to the IDE reducing the patient follow-up from the existing 5-year to 3-year follow up for both the MAVErIC Phase I and Phase II Clinical Trials was submitted on June 6, 2006, and approved on June 16, 2006.
Study Population Description
This device is indicated for use, in conjunction with a Medtronic Vascular embolic protection system,
for improving carotid luminal diameter in patients at high risk for adverse events from carotid endarterectomy who require carotid revascularization and meet the following criteria: 1) Patients with neurological symptoms and > 50% stenosis of the common or internal carotid artery by either ultrasound or angiogram, or patients without neurological symptoms and > 80% stenosis of the common or internal carotid artery by either ultrasound or angiogram, and 2) Patients having a vessel with reference diameters between 4.5 mm and 9.5 mm at the target lesion.
The protocol defined primary endpoint for each phase of the trial was the cumulative incidence
of major adverse events at 1-year, defined as a composite of all-cause death, myocardial infarction (Q wave and non-Q wave), and ipsilateral stroke. The primary endpoint in the statistical analysis plan is defined as the cumulative incidence of major adverse events at 1-year post-procedure, defined as all-cause death, stroke, or MI at 30 days plus all-cause death, MI or ipsilateral stroke within 31 days to 365 days post-procedure.
Followup Visits and Length of Followup
Patient follow up occurring at 30 days for all 1500 patients enrolled in the study
and 365 days for the first 500 patients enrolled.
Final Study Results
Actual Number of Patients Enrolled
MAVErIC I study: 99 patients; MAVErIC II study: 399 patients
Actual Number of Sites Enrolled
Patient Followup Rate
Final Safety Findings
Adjudicated all-cause death rate at 3-years postprocedure was 21.8% (87/399). The total rate of myocardial
infarction was 3.8% (15/399). The total rate of stroke was 6.5% (26/399). The rate of target lesion revascularization was 3.5% (14/399).
Study Strengths and Weaknesses
Strengths: The sponsor did enroll and follow-up additional subjects then was originally asked for by
FDA. Weaknesses: Sponsor did not calculate lost to follow-up based on an intention to treat method. If one was to substitute the study sample size of 399 as the denominator the 3-year follow-up would be 69%.
Recommendations for Labeling Changes
Labeling was not updated since the device is no longer marketed.