RHEIA (Randomized researcH in womEn All Comers With Aortic Stenosis)

Purpose of this prospective, randomized, controlled, multi-center study is to evaluate the safety and efficacy of Transcatheter Aortic Valve Implantation (TAVI) as compared to surgical aortic valve replacement (SAVR) in female patients with severe symptomatic aortic stenosis. Patients will be randomized 1:1 to receive either TAVI or SAVR aortic valve replacement. For TAVI procedure, Edwards SAPIEN 3 THV system Model 9600 TFX (20, 23, 26 and 29 mm) or SAPIEN 3 Ultra THV system Model 9750 TFX (20, 23, 26) with the associated transfemoral delivery systems will be sued, for SAVR any commercially available surgical bioprosthetic valve. Patients will undergo the following visits: Screening, Procedure, Post Procedure, Discharge, 30 day, 6 months (telephone contact) and 1 year.

Recent large meta-analyses and a large retrospective study from the STS/ACC TVT Registry demonstrated improved survival in female versus male aortic sclerosis patients undergoing TAVI despite their advanced age and increased rates of major peri-procedural vascular complications, bleeding events and strokes. These gender-related patient profile differences have also been present in multicentre cohorts across the world. A recent meta-analysis by Siontis et al. showed that TAVI, when compared with SAVR, was associated with a significant 13% relative risk reduction in 2-year mortality, a benefit more pronounced amongst females and patients undergoing transfemoral TAVI. In a recent meta-analysis, the female-specific survival advantage from TAVI over SAVR was explored. Amongst females, TAVI recipients had a significantly lower mortality than SAVR recipients, at 1 year (OR 0.68; 95%CI 0.50 to 0.94). Amongst males there was no difference in mortality between TAVI and SAVR at 1 year (OR 1.09; 95%CI 0.86 to 1.39). There was statistically significant evidence of a difference in treatment effect between genders at 1 year (p interaction = 0.02). In an attempt to explore the mechanisms for an increased mortality rate in women undergoing SAVR, different endpoints were explored in female patients exclusively. It was shown that women, undergoing SAVR, having both a higher periprocedural mortality, higher rates of bleeding and acute kidney injury, worse patient prosthesis match and worse long term recovery of left ventricular function.In the recent PARTNER 3 the composite of death from any cause, stroke, or rehospitalization had occurred in 42 patients (8.5%) in the TAVI group as compared with 68 patients (15.1%) in the surgery group at 1 year. The difference was 6.6% (95%CI -10.8% to -2.3%) and thus exceeded the pre-defined non-inferiority margin of 6%. Subgroup analyses of the primary end point at 1 year showed no heterogeneity of treatment effect in any of the subgroups that were examined including gender (p=0.27). There were 292 women included with an endpoint rate of 18.5% for SAVR (men 13.8%) and 8.1% for TAVI (men 8.7%), showing a clear trend for an increased benefit of women undergoing TAVI instead of SAVR (rate difference -10.4%; 95%CI -18.3% to -2.5%). Nonetheless, the benefits of TAVI were preserved in both men and women.Earlier observational and clinical studies indicated an increased risk for women undergoing SAVR compared to men while being at a comparable risk for TAVI. In a recent meta-analysis of TAVI vs. SAVR in men and women the risk of dying from the intervention was reduced by a relative 32% in women (OR 0.38; 95%CI 0.50-0.94) while there was no such difference in men (OR 1.09; 95%CI 0.86-1.39). This was mostly documented as being the effect of a reduced periprocedural mortality with TAVI (-54%; OR 0.46; 95%CI 0.22-0.96) and major bleeding (-57%; OR 0.43; 95%CI 0.25-0.73) while the difference in strokes and acute kidney injury did not reach statistical significance. Taken all available scientific data on the comparison of TAVI versus open surgery in patients with indication for AVR together it remains probable, that independently of the individual surgical risk female patients in particular seem to benefit from a non-surgical aortic valve replacement strategy. As the indirect comparisons of the intermediate to low risk outcomes in PARTNER 2/3 suggest a favorable risk reduction in women compared to men as described, the investigators believe it is timely for a dedicated trial to demonstrate the non-inferiority of TAVI in women compared to SAVR and, in case of this being true, whether TAVI is actually superior to performing SAVR.