Performance goals and endpoint assessments for clinical trials of femoropopliteal bare nitinol stents in patients with symptomatic peripheral arterial disease.
OBJECTIVE
This analysis proposes safety and performance goals for prospective single-arm trials of bare nitinol stents to treat patients with debilitating claudication associated with femoropopliteal (FP) atherosclerotic lesions.


BACKGROUND
To date there have been no analyses of clinical trials data to set efficacy and safety benchmarks for new bare nitinol stents in the treatment of claudication from FP disease. Industry has been reluctant to sponsor studies of nitinol stents due to logistical barriers.


METHODS
VIVA Physician's, Inc. (VPI) analyzed subject-level data from the PTA control arm of three randomized FDA device trials conducted by industry. Subjects with Rutherford category 2-4 claudication and FP lesion lengths 4-15 cm with 12 month duplex ultrasound (DUS) assessment were identified. These data were combined with the results of a survey of the medical literature (1990-2006) for similar subjects.


RESULTS
Analysis of the industry derived control arm PTA data identified 116 patients (mean lesion length 8.7 cm) with a 12 month DUS defined FP patency of 28%. A similar cohort of 191 patients was identified from the medical literature in which the 12-month vessel patency equaled 37%; from these combined patient cohorts, expected vessel patency for PTA was estimated to equal 33%.


CONCLUSIONS
Based on the PTA performance efficacy rate of 33% derived from industry clinical trial data and the medical literature, and the requirement that the bare nitinol stent 12-month efficacy performance goal be set to equal twice this rate, the patency efficacy goal equals 66%. Additional information is provided on safety and other reporting standards and stent integrity evaluation for bare metal stents.
Rocha-Singh
Krishna J
KJ
Prairie Vascular Institute, Springfield, Illinois 62794-9420, USA. ksingh@prairieheart.com
Jaff
Michael R
MR
Crabtree
Tami R
TR
Bloch
Daniel A
DA
Ansel
Gary
G
D000497:Alloys; D000800:Angioplasty, Balloon / Q000009:adverse effects; D050197:Atherosclerosis / Q000150:complications / Q000503:physiopathology / Q000601:surgery* / Q000628:therapy; D002986:Clinical Trials as Topic / Q000379:methods*; D023381:Endpoint Determination; D005263:Femoral Artery / Q000503:physiopathology / Q000601:surgery*; D017408:Guidelines as Topic; D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D016491:Peripheral Vascular Diseases / Q000150:complications / Q000503:physiopathology / Q000601:surgery* / Q000628:therapy; D011150:Popliteal Artery / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D012042:Registries; D012107:Research Design; D018401:Sample Size; D012720:Severity of Illness Index; D015607:Stents / Q000009:adverse effects; D016896:Treatment Outcome; D014654:Vascular Patency; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods*
D000497:Alloys; C013616:nitinol