EVAR Outcomes Equivalent Between Men and Women, Registries Show

LAS VEGAS, NV—Two registry studies presented here in late-breaking sessions at VIVA 2017 challenge long-held beliefs that women with abdominal aortic aneurysm (AAA) fare far worse after treatment with EVAR than do men.

The studies looked at contemporary populations and show that while anatomical differences are unquestionable, and more women than men are treated outside of instructions for use (IFU), no obvious differences exist in terms of hard outcomes.

“Prior studies have shown that when you look for gender differences in patients undergoing EVAR, that women tend to be more challenging in several ways in terms of presentation, suitability for EVAR, and then also short- and long-term outcomes,” said Marc Schermerhorn, MD (Beth Israel Deaconess Medical Center, Boston, MA).

Looking at 5-year follow-up data from the 1,263-patient ENGAGE Global Registry, Schermerhorn and colleagues found equivalent outcomes between men and women for all-cause mortality, aneurysm-related mortality, rupture, type 1a endoleaks, freedom from secondary endovascular procedures, and aneurysm sac diameter changes.

This, despite the fact that women were about 3 years older on average, were less likely to have been diagnosed with CAD or have had revascularization, and had shorter and more angulated necks and smaller iliacs. Approximately 16.5% of the women had proximal neck lengths < 15 mm compared with 11.5% of men, and approximately 20% of women had infrarenal neck angles of > 60 degrees compared with just 9% of men. Overall, women were twice as likely as men to be implanted outside of IFU due to these neck-size issues (32.3% vs 16.1%; P < 0.001).

Procedure success and length of procedure also did not differ between men and women, nor did length of ICU stay. However, hospital stays were about 1.5 days longer for women than men. All patients in ENGAGE received the Endurant II stent graft (Medtronic) and were followed as part of the postmarket registry.

Undiagnosed Cardiac Issues at the ‘Heart’ of the Matter?

“I’m really happy about the idea that I can use the stent graft in women and hopefully have equal results at 5 years, but I am absolutely confused about how to alter my treatment modalities for women . . . because the predominance of evidence suggests that women don’t do as well with almost every therapy that we have,” observed panelist Peter Schneider, MD (Kaiser Foundation Hospital, Honolulu, HI). He then asked Schermerhorn what practitioners should be looking for and whether there should be a different level of aggressiveness regarding cardiac evaluation in women who are EVAR candidates.

“For me, [the data] are very optimistic and make me feel better about operating at a slightly smaller diameter in women. I personally think we need to figure out what that appropriate threshold should be for women,” Schermerhorn said, adding that indexing to body surface area would seem to make sense. He suggested that stress testing prior to EVAR should be considered if there is concern about undiagnosed CAD.

“Women may have an equivalent amount of cardiac disease; it’s just that they don’t get it diagnosed and treated, and that may be part of what puts them at increased risk for adverse perioperative events [with EVAR],” he noted.

Addressing Underrepresentation

In the second presentation, Jennifer Ash, MD (Christie Clinic Vein & Vascular Center, Champaign, IL), showed 30-day results from the LUCY study, which included 50% women in the 225-patient cohort, all of whom were treated with the low-profile Ovation stent graft (Endologix). Ash noted that women make up about one-quarter of the AAA population but have historically been underrepresented in EVAR trials, with figures ranging from 5% to 13% and no prospective clinical trials dedicated to evaluating outcomes in women.

As with the ENGAGE registry patients, women in LUCY had more complex anatomy than men, but they did not have longer hospital stays. Additionally, for every in-hospital outcome analyzed, the differences between men and women were nonsignificant, as were 30-day readmission rates.

Furthermore, there were no differences in major adverse events, including all-cause mortality, AAA-related mortality, renal failure, bowel ischemia, respiratory failure, and stroke. Type I endoleak occurred in three men compared with none of the women, while type II endoleak occurred in 21 men and eight women, but the differences did not meet statistical significance.

Overall I think this demonstrates that there is a potential for women to fare as well as men in terms of treatment of abdominal aortic aneurysm. Jennifer Ash

In a press conference prior to her presentation, Ash said, “Essentially the significance of the trial is the nonsignificance of the trial.” She added that the similar lengths of stay add something new to the conversation.

“Overall I think this demonstrates that there is a potential for women to fare as well as men in terms of treatment of abdominal aortic aneurysm,” Ash concluded.

But session moderator John Rundback, MD (Holy Name Medical Center, Teaneck, NJ), questioned whether the equivalent safety data will translate to patients who require more complex disease management rather than “the straightforward aneurysms.”

Like Schermerhorn, Ash said she believes diameter size eligibility for intervention needs to be reevaluated in women to account for their higher rate of rupture at all diameter sizes versus their male counterparts.

Panelist Joshua Beckman, MD (Vanderbilt University Medical Center, Nashville, TN), said his take-home from the study is that “for people who are anatomically suitable for these devices, everybody does equally well, and  . . . sex is not an important contributor to outcome in the setting of suitable anatomy.” He added that newer, lower-profile stent grafts may allow clinicians to extent this type of repair to larger numbers of women, noting that “people aren’t excluding women intentionally, because I think everyone would rather put in a device than do an open procedure.” But current technology, Beckman said, amplifies the negative aspects of the anatomical differences.

“Certainly, smaller devices that are more easily placed and maybe handled more like a catheter would make sense in this population,” Ash agreed.