PARIS – Results of the first-ever all-female patient TAVR registry indicate that a history of pregnancy – albeit typically half a century or more ago – is strongly protective against stroke, major bleeding, and other serious adverse events within 30 days of undergoing transcatheter aortic valve replacement.
The explanation for this novel observation remains unclear and warrants further study. One plausible hypothesis: “We can postulate that there is a hormonal effect in pregnancy that is still present after 50 years,” Dr. Alaide Chieffo said in presenting the Women’s International Transcatheter Aortic Valve Implantation (WIN TAVI) registry findings at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.
Dr. Alaide Chieffo
WIN TAVI is a prospective observational registry of women undergoing TAVR for symptomatic severe aortic stenosis. Dr. Chieffo reported on acute and 30-day outcomes in 1,019 women enrolled in the registry at 20 highly experienced TAVR centers in Europe and North America. The average age was 82.5 years and mean STS score was 8.3%, putting the women at intermediate to high risk. Nearly three-quarters of subjects were more older than 80 years. Most patients had at least three major procedural risk factors. Two-thirds of the women were deemed frail upon surgical assessment.
The rationale for creating the WIN TAVI registry lies in the fact that even though half of patients undergoing TAVR are women, their optimal treatment strategy remains undefined. This is an important issue, particularly in light of evidence to suggest that the superiority of transfemoral TAVR over surgical aortic valve replacement in the PARTNER 2A trial may have been driven by better outcomes in women than in men.
WIN TAVI is designed to evaluate the safety and performance of TAVR in women in real-world clinical practice. It’s also a unique opportunity to prospectively gather data on female sex-specific baseline characteristics that haven’t been collected in previous TAVR studies and to examine their influence on outcomes, explained Dr. Chieffo of San Raffaele Scientific Institute in Milan. The primary outcome was the 30-day standard Second Valve Academic Research Consortium (VARC 2) composite of all-cause mortality, stroke, life-threatening bleeding, major vascular complications, stage 2 or 3 acute kidney injury, coronary artery obstruction, or a repeat intervention for valve-related dysfunction. The incidence was 14.4%, including a 3.9% all-cause mortality rate, a 1.3% incidence of stroke, major vascular complications in 7.9% of women, and a 4.4% incidence of life-threatening bleeding.
“The findings of the current registry underscore the importance and safety of moving to a lower-risk population of women with TAVR,” Dr. Chieffo declared.
The VARC 2 rates seen in WIN TAVI are low in comparison to other reports in TAVR patients. Dr. Chieffo attributed this to several factors. Patients underwent current state-of-the-art TAVR procedures, with a percutaneous transfemoral approach used in 91% of cases. Only one-third of patients had general anesthesia; the rest underwent TAVR under conscious sedation or a local anesthetic. One-third of the procedures were carried out with sheath sizes of 16 French or less.
Moreover, 42% of patients received new-generation TAVR devices that are compatible with smaller sheath sizes, are completely or partially retrievable, and have a lower paravalvular leak rate than that of earlier devices. The predominantly female interventional cardiologists were all highly experienced, and more than three-quarters of patients were discharged on dual-antiplatelet therapy or an oral anticoagulant.
Seventy-two percent of women had a remote history of pregnancy. Their rate of the primary VARC 2 safety endpoint was 12.7%, compared to 18.9% in patients without a prior pregnancy. In a multivariate logistic regression analysis, prior pregnancy, regardless of whether it resulted in a live birth, was independently associated with a 43% reduction in the risk of a VARC 2 safety endpoint. The greater the number of a woman’s pregnancies, the larger the reduction in the rate of VARC 2 complications.
The other independent predictor of reduced risk was the use of a new-generation TAVR device, defined as any device commercially available in Europe other than the Edwards Sapien XT or Medtronic CoreValve. The newer devices were associated with a 41% relative risk reduction in the VARC 2 composite endpoint.
Risk factors for the primary safety endpoint were prior stroke, associated with an adjusted twofold increased risk; a left ventricular ejection fraction less than 30%, with a 2.6-fold increased risk; and advanced age.
Of note, while 17.5% of women had a history of osteoporosis, only one-fifth of them were on treatment for it. This may impose important limitations on their postprocedural functional recovery, according to Dr. Chieffo.