Paradoxical clinical outcomes of severe versus very severe aortic valve stenosis after transcatheter aortic valve implantation? a propensity score matched analysis and review of literature

Background: Very severe aortic stenosis (VSAS) is a critical condition with unfavourable clinical outcomes if left untreated or treated by surgical valve replacement. In contrast, after transcatheter valve implantation (TAVI) outcomes seem to be similar or-paradoxically-even better compared to severe aortic stenosis (SAS), as indicated by previous studies. Methods: Data of patients from a single centre who underwent TAVI were retrospectively analysed. Patients with concordant AS (n = 475) were divided into SAS (n = 379) and VSAS (n = 96) groups. These groups are compared in terms of procedural (safety) and long-term (efficacy) outcomes, using propensity score matching. In addition, a review of relevant literature is provided. Results: After propensity score matching, 96 patients remained in each group. Procedural outcomes did not differ significantly between VSAS and SAS groups. Cox proportional hazards regression analysis showed a favourable trend toward lower overall mortality within a mean follow-up of 42 months after TAVI in the VSAS group (hazard ratio, HR, 0.668; 95 % confidence interval, CI, 0.430-1.038). This difference did not reach statistical significance (p = 0.073), however, it was significant in the subgroups of females (p = 0.045) and patients with NYHA class III (p = 0.043). Conclusion: Our analysis confirms-in line with previous studies-that patients with VSAS represent a substantial subgroup and have at least as favourable or-paradoxically-even better clinical results after TAVI compared to patients with SAS. Therefore, TAVI should not be withheld from these patients.