DREAM's 6-Year Survival Rates for EVAR Equal to OAR

May 20, 2010—Long-term findings from the DREAM (Dutch Randomized Endovascular Aneurysm Management) trial comparing open surgical repair (OAR) and endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) have been published by Jorg L. De Bruin, MD, et al in the New England Journal of Medicine (2010:362;1881–1889).

According to the DREAM investigators, randomized trials have shown an initial overall survival benefit for elective EVAR versus conventional OAR for patients with large AAAs; however, this survival difference was no longer significant in the second year after the procedure. Therefore, the aim of DREAM was to determine if the comparative outcomes at more than 2 years after surgery are important for clinical decision-making.

The investigators conducted a long-term, multicenter, randomized controlled trial comparing OAR with EVAR in 351 patients with a AAA ≥ 5 cm in diameter who were considered suitable candidates for both techniques. The primary outcomes were rates of death from any cause and reintervention. Survival was calculated with the use of Kaplan–Meier methods on an intentionto- treat basis. The investigators randomly assigned 178 patients to undergo OAR and 173 to undergo EVAR. At 6 years after randomization, the cumulative survival rates were 69.9% for OAR and 68.9% for EVAR (95% confidence interval, -8.8–10.8; P = .97). The cumulative rates of freedom from secondary interventions were 81.9% for OAR and 70.4% for EVAR (95% confidence interval, 2–21; P = .03). At 6 years, OAR and EVAR demonstrate similar survival rates but EVAR shows a significantly higher rate of secondary interventions, the investigators concluded.

Also in the New England Journal of Medicine, the United Kingdom EVAR trial investigators published the 10-year outcomes from their studies of OAR-eligible (2010;362:1863–1871) and OAR-ineligible patients (2010; 362:1872–1880). These findings were published online ahead of print on April 10 in conjunction with their presentation at the Charing Cross Symposium in London. Endovascular Today's News summary of these findings can be read in the May 2010 issue (2010;9:28–30). In an editorial in the New England Journal of Medicine, K. Craig Kent, MD, discussed the implications of the DREAM and UK EVAR trial findings (2010;362:1930–1931).

“Trials that are designed to evaluate new interventions are frequently confounded by continued evolution of the technology,” commented Dr. Kent. “The DREAM and EVAR-1 trials were initiated 10 and 11 years ago, respectively, and over time, endovascular graft design has evolved substantially. Moreover, patient selection, surgeon experience, and treatments for graft complications have also improved over time. It is not unreasonable to assume that current outcomes for endovascular repair are substantially better than those reported in these trials.”

“It is also important to note that many patients with treatable aneurysms fall outside the inclusion criteria for these studies. In the EVAR-1 trial, nearly 5,000 patients were screened to identify the 1,252 who underwent randomization. Thus, clinicians should be cautious not to generalize these findings to all patients needing aneurysm repair.”

“All patients should be informed of the advantages and disadvantages of endovascular repair; some will be willing to assume the up-front risk of open surgery to avoid the late consequences of endovascular repair, and others will not,” Dr. Kent concluded. “Although many questions remain unanswered, the results of these studies provide additional insight into how we should treat patients with aneurysmal disease.”