United Kingdom Endovascular Aneurysm Repair 1 - EVAR 1

Contribution To Literature:

The EVAR 1 trial showed that while endovascular repair of abdominal aortic aneurysms is safer in the short-term, the long-term durability of this treatment option is inferior to open repair.

Description:

The goal of the trial was to evaluate treatment of abdominal aortic aneurysms by endovascular repair compared with open repair among patients suitable for either approach.

Study Design

  • Parallel

Patients Enrolled: 1,252
Mean Follow-Up: Median of 6.0 years
Mean Patient Age: 74 years
Female: 10%

Patient Populations:

  • Patients at least 60 years of age and suitable for either endovascular or open repair
  • Abdominal aortic aneurysm at least 5.5 cm in diameter

Primary Endpoints:

  • All-cause mortality

Secondary Endpoints:

  • Aneurysm-related mortality
  • Graft-related complication
  • Graft-related reintervention

Drug/Procedures Used:

Patients with an abdominal aortic aneurysm were randomized to endovascular repair (n = 626) versus open repair (n = 626).

Principal Findings:

Overall, 1,252 patients were enrolled. There was no difference in baseline characteristics between the groups. In the endovascular repair group, the mean age was 74 years, 90% were men, mean diameter of the abdominal aortic aneurysm was 6.4 cm, body mass index was 27 kg/m2, 12% of patients never smoked, mean systolic blood pressure was 148 mm Hg, use of aspirin was 54%, and statin was 35%.

The 30-day operative mortality was 1.8% in the endovascular repair group versus 4.3% in the open repair group (p = 0.02). The all-cause death rate was 7.5/100 person-years in the endovascular group versus 7.7/100 person-years in the open group (p = 0.72). There was a marginal benefit in this outcome within 6 months (adjusted hazard ratio [HR] 0.61, p = 0.06); although not between 6 months and 4 years (adjusted HR 1.12, p = 0.39) or after 4 years (adjusted HR 1.09, p = 0.57).

The aneurysm-related death rate was 1.0/100 person-years in the endovascular group versus 1.2/100 person-years in the open group (p = 0.73). There was a benefit in this outcome within 6 months (adjusted HR 0.47, p = 0.03); although not between 6 months and 4 years (adjusted HR 1.46, p = 0.44). There was a hazard of aneurysm-related deaths after 4 years (adjusted HR 4.85, p = 0.05).

After endovascular repair, the hazard for graft-related complications was increased (adjusted HR 4.39, p < 0.001), as was the hazard for graft-related reinterventions (adjusted HR 2.86, p < 0.001). Long-term ruptures were only seen after endovascular repair.

15-year follow-up:

Long-term all-cause mortality: 9.3 deaths per 100 person-years with EVAR vs. 8.9 deaths per 100 person-years with open repair (p = 0.14).

Between 0 and 6 months, EVAR was associated with a lower total mortality (adjusted HR 0.61, 95% CI 0.37-1.02) and a lower aneurysm-related mortality (adjusted HR 0.47, 95% CI 0.23-0.93).

Beyond 8 years, EVAR was associated with a higher total mortality (adjusted HR 1.25, 95% CI 1.00-1.56) and a higher aneurysm-related mortality (adjusted HR 5.82, 95% CI 1.64-20.65).

Interpretation:

Among patients with abdominal aortic aneurysm, endovascular repair was associated with lower operative mortality and aneurysm-related deaths within 6 months. Unfortunately, late ruptures only occurred in the endovascular repair group, which contributed to a greater overall frequency of complications, reinterventions, long-term aneurysm-related deaths, and long-term total mortality.

Long-term data regarding the efficacy and safety of endovascular repair of abdominal aortic aneurysm are limited. The EVAR 1 trial demonstrates that endovascular repair is associated with short-term benefits; however, the durability of this approach is inferior to open repair. Since the enrollment period of this trial, newer devices for endovascular repair are now available. These data are important in counseling patients with abdominal aortic aneurysm regarding their potential treatment options. Further study is needed to determine if these newer devices might be associated with more favorable long-term results.

References:

Patel R, Sweeting MJ, Powell  JT, Greenhalgh RM, on behalf of the EVAR Trial Investigators. Endovascular versus open repair of abdominal aortic aneurysm in 15 years’ follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial. Lancet 2016;Oct 12:[Epub ahead of print].

The United Kingdom EVAR Trial Investigators. Endovascular versus open repair of abdominal aortic aneurysm. N Engl J Med 2010;Apr 11:[Epub ahead of print].

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Vascular Medicine, Interventions and Vascular Medicine

Keywords: Cause of Death, Endovascular Procedures, Body Mass Index, Smoke, Blood Pressure, Aortic Aneurysm, Abdominal, Systole, Peripheral Vascular Diseases, Vascular Surgical Procedures


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