Gender and TAVR: Studies Highlight Different Outcomes Between Men and Women

ORLANDO, FL—A new analysis suggests that men truly are from Mars and women from Venus, at least when it comes to clinical outcomes after TAVR.

Among more than 23,000 men and women who underwent the procedure, women were significantly more likely to be alive at 1 year compared with men but also were more likely to encounter in-hospital vascular complications, including bleeding.   

The analysis, based on data from the STS/ ACC TVT Registry, was presented here last week at SCAI 2016 by Jaya Chandrasekhar, MBBS (Icahn School of Medicine at Mount Sinai, New York, NY), and confirms prior studies suggesting sex-based differences in clinical outcomes following TAVR.

Those studies, said Chandrasekhar, also showed better survival in women compared with men, accompanied by greater procedural complications, but the reasons for the survival advantage among women are unclear.

In this latest analysis, 21.3% of women had died at 1 year compared with 24.5% of men (HR 0.73; 95% CI 0.63-0.85). The rate of in-hospital vascular complications was nearly doubled among women (8.3% vs 4.4%; P < 0.001), and there was a trend toward a greater incidence of bleeding (8.0% vs 6.0%; P = 0.08).   

Explaining Mortality Difference

Speaking with the media, Chandrasekhar said women in the registry had a lower prevalence of traditional risk factors such as diabetes, prior revascularization, CAD, atrial fibrillation, and lung disease but added that their smaller body surface area, lower glomerular filtration rate, and higher prevalence of porcelain aorta, moderate or severe mitral valve regurgitation, and moderate or severe triscuspid valve regurgitation also add to their overall level of risk.

Chandrasekhar hypothesized that the lower mortality seen in women may be related to fewer systemic baseline risks, including less CAD. Another important finding was that despite similar device success, women were more likely than men to have cover index ≥ 8%, suggesting a lower risk of paravalvular aortic incompetence.

Most patients were at prohibitive risk or high risk for TAVR, with more women than men being considered by the heart team to be debilitated or deconditioned .Chandrasekhar also noted that more women than men underwent nontransfemoral TAVR, which raises risks for vascular complications and bleeding. Other differences that also may have increased risk included more cutdowns and smaller device sizes in women compared with men. Rate of conversion to open surgery, though low in the overall study population, was also more frequent among women.

Panelist Cindy Grines, MD (Detroit Medical Center, Detroit, MI), acknowledged that women respond differently to certain stressors, but said she was pleased the data show women are benefiting from TAVR and showing early signs of left-ventricular hypertrophy regression.

Ted Feldman, MD (NorthShore University Health System, Evanston, IL), weighed in on the findings, too, saying it’s important to pursue further study of these fundamental differences between men and women. Right now, there is only a “little bit of data on a very different response to pressure overload in men versus women, with men tending to dilate and women hypertrophying,” he noted.

Small Potential Advantage for Bivalirudin in Women

In a second study, presented at SCAI by Anita W. Asgar, MD (Montreal Heart Institute, Montreal, Canada), researchers found gender had no influence on early TAVR outcomes based on the type of anticoagulation regimen used. They did observe a trend toward better survival among women with bivalirudin that was not observed in men.

The study, which was simultaneously published online ahead of print in Catheterization and Cardiovascular Interventions, utilized data from the multicenter BRAVO 3 study, originally presented as a late-breaking trial at TCT 2015. That trial randomized 802 high-risk patients undergoing transfemoral TAVR at 31 sites in Europe and North America to treatment with bivalirudin (Angiomax, The Medicines Company) or a weight-adjusted bolus of unfractionated heparin. Overall, BRAVO 3 found that bivalirudin was as effective as, but no better than, heparin at reducing major bleeding or adverse cardiac events.

In the new analysis, Asgar and colleagues looked at outcomes by gender among 411 men and 391 women. Compared with men, women were older, had fewer comorbidities, and had lower EuroSCORE. In women, sheath and device sizes were smaller, but there was similar use of postdilation and vascular closure devices compared with men. Two-thirds of all patients received balloon-expandable valves, while the other third received self-expanding devices.

Overall, there were no differences between men and women at 48 hours or 30 days for the primary endpoint of BARC-defined major bleeding, death, stroke or MI, MACE, or net adverse cardiovascular events (NACE), nor was there a difference in the risk of vascular complications.

Additionally, no differences were seen in rates of major bleeding by sheath size between men and women at either 48 hours or 30 days. When outcomes were examined for the effect of bivalirudin versus heparin, there again were no sex differences, with the exception of a trend for lower all-cause mortality at 48 hours with bivalirudin in women (1.0% vs 3.6%) but not in men (P for interaction = 0.009). At 30 days, the trend towards benefit with bivalirudin in women remained for the outcomes of all-cause and MACE (P for interaction = 0.10 for both).

‘Encouraging’ Data Reflect Contemporary Practice

Asgar said the sex-based BRAVO 3 analysis is “the first time we actually see that there’s no difference between women and men in terms of early major bleeding or vascular complications.” She called the trend toward lower mortality in women with bivalirudin “hypothesis generating” and “an interesting signal.”

The lack of differences in outcomes between men and women despite what has been shown in prior studies, she said, “really reflects the contemporary practice of TAVR and how we’re getting better” in terms of both operator experience and reductions in transfemoral complications.

After the presentation, panelist Bonnie H. Weiner, MD (Saint Vincent Hospital, Worcester, MA), said “it’s very encouraging that there doesn’t seem to be a persisting difference of vascular complications” in men versus women.

Disclosures:

• Asgar reports research support from Abbott and consultant/speaker honoraria from Abbott, Edwards Lifesciences, Gore and Medtronic.  
• Chandrasekhar reports no relevant conflicts of interest. 

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• Meta-analysis: Women Fare Better Than Men After TAVR Despite More Complications