EVAR-First Strategy for Ruptured AAA Provides Early QoL Benefit.
Treating ruptured aortic abdominal aneurysms (AAAs) with endovascular aneurysm repair (EVAR), if possible, rather than open repair does not reduce mortality, according to midterm follow-up of the randomized IMPROVE trial published online April 8, 2015, ahead of print in the European Heart Journal. However, an EVAR-first strategy does improve early quality of life (QoL) and may be more cost-effective.
Investigators led by Janet T. Powell, MD, PhD, of Charing Cross Hospital (London, England), analyzed 613 patients (mean age 76.7 years; 78% men) with clinical diagnosis of ruptured AAA or aortoiliac aneurysm who were treated at 1 Canadian and 29 British centers between September 2009 and July 2013. Patients were randomized to open repair (n = 297) or immediate CT scanning followed by EVAR if morphologically suitable (n = 316).
Thirty-day results, published online January 13, 2014, in the BMJ, showed no difference in mortality or cost between the 2 approaches.
Baseline characteristics were similar between the groups. Mean aneurysm diameter was 8.4 cm and admission systolic blood pressure was 110 mm Hg. After imaging, 536 patients had proven rupture. According to the BMJ paper, only 150 of those assigned to the endovascular strategy actually underwent EVAR, while 112 had open repair and 17 had no repair. Within the open repair group, 36 had EVAR, 220 had open repair, and 19 had no repair.
No Mortality Difference per Protocol or per Treatment
After 1 year, all-cause mortality rates were similar between the EVAR-first and open repair groups, as were adjusted risk and the risk among patients who actually underwent either type of repair. Almost half of the deaths occurred within 24 hours, and the majority happened within 30 days in both groups. AAA-related mortality was also similar between the groups at 1 year (table 1).
However, subgroup analysis found “weak evidence” that the endovascular strategy was more effective in women than men (OR 0.41; 95% CI 0.18-0.93).
There was no difference in time to first reintervention between the randomized groups and for the patients who underwent repair. Between 31 days and 1 year, 11 patients (4.2%) in the endovascular group and 9 (3.7%) in the open repair group underwent reintervention.
Endovascular patients were released from the hospital sooner than surgical patients (after an average of 17 vs 26 days) and were more likely to be discharged to home from the primary hospital (both P < .001).
At 3 months, patients assigned to the EVAR-first strategy scored higher on the EQ-5D QoL questionnaire covering mobility, self-care, and pain than those who underwent surgery (0.76 vs 0.69 on a scale from 0 [for death] to 1 [for perfect health]; P = .0296).
Average total costs including the procedure were a mean of £2,329 (approximately $3,544 in 2013 dollars) less with the endovascular strategy than with surgery. The quality-adjusted life-year (QALY) gain at 1 year for the endovascular group was 0.052 (95% CI -0.005 to 0.108), with similar results across subgroups. When resource costs and QALYs were used to estimate cost-effectiveness, the endovascular strategy was found to be “dominant” in 87% of cases, with lower mean costs and higher mean QALYs. The incremental net benefit of the endovascular strategy vs open repair was positive at £3,877 (approximately $5,900), a finding that was robust over a range of cost assumptions.
‘Patient-Preferred Outcomes’ More Pertinent
In a telephone interview with TCTMD, Christopher K. Zarins, MD, of Stanford University Medical Center (Stanford, CA), called IMPROVE the “best study” so far on management of ruptured AAAs.
He questioned, though, whether mortality deserved to be the primary outcome, suggesting that “patient-preferred outcomes” are more relevant.
“What patients want is to be discharged faster, to go home, and to have a good quality of life,” Dr. Zarins said. “The data show that if you follow [an EVAR-first] approach, you wind up with much better outcomes from the patient’s perspective. That seems to me like a very good message.”
On the other hand, he added, “The system is concerned about cost-effectiveness, and it actually turned out to be more cost-effective to use EVAR.”
Dr. Zarins stressed, however, that hospitals that repair ruptured AAA should offer both therapies “because it’s impossible to do EVAR or open repair in 100% of cases.”
It remains to be seen whether longer-term follow-up will bring any surprises, he said, citing an ongoing issue with the durability of EVAR. “At the same time,” Dr. Zarins pointed out, “these patients are older and sicker,” and sustaining a rupture means they would have shorter life expectancy than those receiving elective repair. As such, patients with ruptured AAAs may die before their outcomes would fall into the category of “long-term,” he explained.
In addition, the similarity of reintervention rates—which could affect cost-effectiveness—between EVAR and open repair is believable, Dr. Zarins said. The idea that surgery almost never requires reintervention is a misunderstanding based on underreporting in the surgical literature, he explained.
Trial Design Hinders Interpretation
Sherif Sultan, MB, BCh, MD, of University Hospital Galway (Galway, Ireland), homed in on the trial’s limitations.
In an email with TCTMD, he noted that “IMPROVE is a comparison of treatment algorithms… rather than the treatments themselves.” It is difficult to draw clinical lessons from a trial analyzed on an intention-to-treat basis when there was “massive crossover between groups,” he said, noting that of the 316 patients randomized to an endovascular-first strategy, only about half actually received EVAR and 112 ultimately received open repair.
For the same reason, the cost analysis is “not very robust,” Dr. Sultan asserted. A “per-treatment” cost analysis would be far more useful to healthcare managers seeking to justify enhanced use of EVAR for ruptured AAA, he noted.
Moreover, Dr. Sultan observed, meaningful evaluation of treatment costs must take into account the context. “The unique UK setting in which 2 teams need to be enlisted to perform a single procedure is… not the norm for most international centers,” he said. “Most contemporary units have endovascular surgeons who are… trained to perform both open and endovascular repair with equipoise.
“Unfortunately, although intuitively one would believe that treating patients with [ruptured AAA] by EVAR at experienced centers should be our modus operandi, the IMPROVE study is flawed in terms of design and analysis and so… does not give statistical support to such a clinical strategy,” Dr. Sultan concluded.
Grieve R, Gomes M, Sweeting MJ, et al. Endovascular strategy or open repair for ruptured abdominal aortic aneurysm: one-year outcomes from the IMPROVE randomized trial. Eur Heart J. 2015;Epub ahead of print.
- The trial was supported by a UK Health Technology Assessment award.
- Drs. Powell and Zarins report no relevant conflicts of interest.
- Dr. Sultan reports serving as a vice president of the International Society for Vascular Surgery.