PARIS – Although female sex is a risk factor for worse outcomes after conventional cardiac surgery, the opposite appears to be true following transcatheter aortic valve implantation.
Among 260 consecutive patients undergoing TAVI for severe, symptomatic aortic stenosis, female sex was associated with significantly better 1-year survival (76% vs. 65%).
The study, described as the first analysis of sex difference with this emerging technique, also identified female sex as an independent predictor of long-term survival, lead author Dr. Kentaro Hayashida and his colleagues reported at the annual congress of the European Society of Cardiology.
The increased survival rate among women who were treated with TAVI may represent a paradox in the cardiovascular disease gender gap.
"Surgical aortic valve replacement in female patients is technically demanding because of their smaller stature and body surface area, higher body mass index, and smaller aortic root," Dr. Hayashida of the Institut Cardiovasculaire Paris-Sud (ICPS) in Massy, France, said in an interview. "In our study cohort, TAVI was performed with a similar device success rate, compared to males, because of the procedural feasibility inherent in this novel technique, despite the specific characteristics associated" with female sex.
TAVI was successfully achieved in 91% of women and 88.4% of men, a nonsignificant difference. Similarly, no significant sex differences were observed for 30-day mortality (12% for women and 18% for men).
Longer life expectancy and early detection of aortic stenosis in women may, in part, have contributed to their improved survival, coauthor and colleague Dr. Philippe Garot said. He pointed out that despite both sexes having made gains in cardiovascular disease mortality from 1950 to 1999, an 80-year-old man in France can expect to live 8.3 more years, compared with 10.5 additional years for an 80-year-old French woman.
The average age at the time of surgery was 83 years in both study groups.
At baseline, women had a significantly lower logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) (22% vs. 26%), higher left ventricular ejection fraction (54% vs. 47%) and less coronary artery disease (49% vs. 79%), peripheral artery disease (27% vs. 40%) and previous cardiac surgery (14% vs. 26.4%) than did men.
Women, however, also had a significantly smaller femoral artery size (7.74 mm vs. 8.55 mm), annulus size (20.9 mm vs. 22.9 mm) and valve size (23.9 mm vs. 26.3 mm) than did men, Dr. Garot said.
TAVI is emerging as the standard of care for patients with severe aortic stenosis who cannot undergo surgery, after the procedure demonstrated similar 1-year survival rates as did conventional aortic valve replacement among older, high-risk patients in the recent PARTNER (Placement of Aortic Transcatheter Valve) trial (N. Engl. J. Med. 2010;363;1597-607). A preliminary subgroup analysis suggested a benefit with the less-invasive TAVR among women and in those without prior coronary artery bypass surgery.
In a multivariate analysis of the current cohort, male sex was identified as an independent predictor of long-term mortality (odds ratio, 1.80), the authors reported. Other significant risk factors were previous cardiac surgery (OR, 2.3), postprocedural aortic regurgitation (OR, 2.3), transfusion of four or more units (OR, 2.5), acute kidney injury (OR, 6.9), and conversion to open surgery (OR, 5.1).
Notably, vascular complications were not associated with mortality in the study, Dr. Garot said.
Based on the current results, Dr. Hayashida said it seems too early to conclude that TAVI should be routinely recommended in women who are not at high risk for conventional surgery.
"After confirmation by other studies of larger patient populations in the future, maybe we can say ‘yes,’ " he added.
Data were prospectively collected on 131 women and 129 men with severe aortic stenosis who were treated at the ICPS from September 2006 through December 2010. TAVI was performed using the Edwards Sapien or Sapien XT valves (85%) or the third-generation CoreValve Revalving system (15%), with 65% of valves placed via the transfemoral approach.
Dr. Hayashida and his coauthors report no conflicts.