Females have better short- and long-term survival after transcatheter aortic valve replacement (TAVR), based on real-world data from two high-volume Canadian facilities. The study was published Sept. 4 in the Journal of the American College of Cardiology.
TAVR is an effective alternative to surgical valve replacement in symptomatic patients with severe aortic stenosis, but the impact of sex on outcomes remains unclear, according to the study authors. In the randomized PARTNER (Placement of Aortic Transcatheter Valves) Cohort A trial, a pre-specified subgroup analysis suggested the mortality benefit of TAVR over surgical replacement at one year was greater in women (N Engl J Med 2011;364:2187-2198). Further examination of the data from the TAVR-only arm demonstrated greater benefit in women but without adjustment for potential baseline differences between women and men.
In this study, Karin H. Humphries, MBA, DSc, of the divisions of cardiology and nephrology and the pharmacy department at St. Paul's Hospital in Vancouver, British Columbia, and colleagues evaluated 641 consecutive patients undergoing TAVR at St. Paul’s and the Quebec Heart and Lung Institute in Quebec City. They examined differences in all-cause mortality with Kaplan-Meier estimates, adjusted logistic regression and proportional hazards models between the two genders.
TAVR was performed with balloon-expandable valves, Cribier-Edwards, Edwards Sapien, Edwards Sapien XT (Edwards Lifesciences) and self-expanding valves (CoreValve, Medtronic; Portico, St. Jude Medical; and Centera, Edwards Lifesciences). Four valve sizes were used: 20, 23, 26 and 29 mm. Transfemoral access was the preferred route, according to the researchers, except in patients with unsuitable iliofemoral arteries.
The primary endpoints were 30-day all-cause mortality and two-year survival. The safety endpoints—vascular complications, bleeds and stroke—were defined according to the Valve Academic Research Consortium criteria.
Women comprised 51.3 percent of the cohort. In the study, balloon-expandable valves were used in 97 percent of cases, with transapical approach in 51.7 percent of the time in women and 38.1 percent of the time in men.
At baseline, women had higher aortic gradients and worse renal function but better ejection fractions. Men had more comorbidities: prior MI, prior revascularization and chronic obstructive pulmonary disease.
“It is unlikely the observed female advantage can be explained by the observed baseline differences, given that extensive adjustment for demographic, procedural and clinical differences failed to attenuate the sex difference,” the researchers wrote.
They reported that more men (11.2 percent) than women (6.5 percent) died at 30 days, and the benefit persisted for two years.
The 30-day rates of stroke and permanent pacemaker implantation did not differ by sex. Women had more major/life-threatening bleeds (21.6 percent vs. 15.8 percent), more blood transfusion (9.5 percent vs. 3.6 percent) and more major vascular complications (12.4 percent vs. 5.4 percent).
The study was limited to two large centers that predominately used balloon-expandable devices, so as a limitation, the results might not be generalizable to other centers and other types of valves.
When considered in the context of the PARTNER A findings, Humphries et al suggested that their results demonstrated that TAVR might be the preferred mode of treatment in elderly women with symptomatic severe aortic stenosis.