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.
A non-randomized, multicenter, prospective, single- arm study.
Study Population Description
Patients enrolled in the pivotal STROLL study who received the S.M.A.R.T. Nitinol Self-Expandable Stent. There
is no pre-specified control group.
39 sites in the United States. A total of evaluable subjects at 3 year follow-up.
Primary safety endpoint: A composite of all-cause death, amputation and target lesion revascularization (TLR) at
Secondary Endpoints to be assessed at 2 and 3 years: (1) individual components of the composite safety endpoint including death, amputation and TLR, (2) Major adverse events (MAE) defined as: death, limb ischemia/amputation of target limb, TLR, or significant embolic events causing organ damage, (3) Stent fracture rate assessed by x-ray, (4) Clinically driven TLR, and target vessel revascularization (TVR), (5) Patency of the target vessel assessed by duplex ultrasound, (6) Limb ischemia assessed by Rutherford/Becker classification, and (7) Ankle brachial index.
Followup Visits and Length of Followup
No new enrollments are planned for the post-approval study.
3 years following index procedure.
Final Study Results
Actual Number of Patients Enrolled
Actual Number of Sites Enrolled
Patient Followup Rate
90.9% (190/209) [209 = number of patients eligible for 3 year visit]
Final Safety Findings
At 3 years the composite endpoint death, index limb amputation, or clinically driven TLR was
31.5% (70/222, 1-sided upper bound 97.5% CI: 38.1), which is lower than the PG of 57% [the denominator 222
= number of patients with a major complication within 1080 days or patients with sufficient follow-up
(i.e. at least 1020 days for 1080-day visit)]. Thus the primary endpoint was met. KM estimate for the composite endpoint (secondary Analysis) was 30.3%.
MAE rate (overall) at 3 years: 31.5% (70/222) Death = 9.9% (22/222)
The study achieved a high follow-up rate of about 91% at 3 year, with enough
patients with 3 year data
for endpoint analysis. The primary safety endpoint was evaluated by a formal statistic and compared to a performance goal.
The PAS population was the premarket cohort that was required to meet certain eligibility criteria. Thus, the study results may not reflect the device performance in routine clinical device.
Recommendations for Labeling Changes
Labeling change is recommended to reflect the long term data from the post-approval study. The
labeling change should include a new section on the label showing a summary of the post-approval study methods (including study objectives, design, population, number of enrolled sites/subjects, key endpoints, follow ¿up visits etc.), results and study strengths and limitations.