Results of PREVENT III: a multicenter, randomized trial of edifoligide for the prevention of vein graft failure in lower extremity bypass surgery.
OBJECTIVE
The PREVENT III study was a prospective, randomized, double-blinded, multicenter phase III trial of a novel molecular therapy (edifoligide; E2F decoy) for the prevention of vein graft failure in patients undergoing infrainguinal revascularization for critical limb ischemia (CLI).


METHODS
From November 2001 through October 2003, 1404 patients with CLI were randomized to a single intraoperative ex vivo vein graft treatment with edifoligide or placebo. After surgery, patients underwent graft surveillance by duplex ultrasonography and were followed up for index graft and limb end points to 1 year. A blinded Clinical Events Classification committee reviewed all index graft end points. The primary study end point was the time to nontechnical index graft reintervention or major amputation due to index graft failure. Secondary end points included all-cause graft failure, clinically significant graft stenosis (>70% by angiography or severe stenosis by ultrasonography), amputation/reintervention-free survival, and nontechnical primary graft patency. Event rates were based on Kaplan-Meier estimates. Time-to-event end points were compared by using the log-rank test.


RESULTS
Demographics, comorbidities, and procedural details reflected a population with CLI and diffuse atherosclerosis. Tissue loss was the presenting symptom in 75% of patients. High-risk conduits were used in 24% of cases, including an alternative vein in 20% (15% spliced vein and 5% non-great saphenous vein) and 6% less than 3 mm in diameter; 14% of the cases were reoperative bypass grafts. Most (65%) grafts were placed to infrapopliteal targets. Perioperative (30-day) mortality occurred in 2.7% of patients. Major morbidity included myocardial infarction in 4.7% and early graft occlusion in 5.2% of patients. Ex vivo treatment with edifoligide was well tolerated. There was no significant difference between the treatment groups in the primary or secondary trial end points, primary graft patency, or limb salvage. A statistically significant improvement was observed in secondary graft patency (estimated Kaplan-Meier rates were 83% edifoligide and 78% placebo; P = .016) within 1 year. The reduction in secondary patency events was manifest within 30 days of surgery (the relative risk for a 30-day event for edifoligide was 0.45; 95% confidence interval, 0.27-0.76; P = .005). For the overall cohort at 1 year, the estimated Kaplan-Meier rate for survival was 84%, that for primary patency was 61%, that for primary assisted patency was 77%, that for secondary patency was 80%, and that for limb salvage was 88%.


CONCLUSIONS
In this prospective, randomized, placebo-controlled clinical trial, ex vivo treatment of lower extremity vein grafts with edifoligide did not confer protection from reintervention for graft failure.
Conte
Michael S
MS
Division of Vascular Surgery, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. mconte@partners.org
Bandyk
Dennis F
DF
Clowes
Alexander W
AW
Moneta
Gregory L
GL
Seely
Lynn
L
Lorenz
Todd J
TJ
Namini
Hamid
H
Hamdan
Allen D
AD
Roddy
Sean P
SP
Belkin
Michael
M
Berceli
Scott A
SA
DeMasi
Richard J
RJ
Samson
Russell H
RH
Berman
Scott S
SS
D000368:Aged; D000369:Aged, 80 and over; D004311:Double-Blind Method; D050684:E2F Transcription Factors / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006083:Graft Occlusion, Vascular / Q000188:drug therapy* / Q000517:prevention & control*; D006084:Graft Rejection / Q000517:prevention & control; D006085:Graft Survival; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D011183:Postoperative Complications / Q000517:prevention & control; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D014654:Vascular Patency / Q000187:drug effects; D014656:Vascular Surgical Procedures / Q000009:adverse effects* / Q000379:methods
D050684:E2F Transcription Factors