Table 1_Transcatheter aortic valve replacement in failed transcatheter versus failed surgical bioprostheses: a systematic review with exploratory meta-analysis.docx

Two full-text studies contributed to the primary quantitative analyses. TAV-in-TAV was not associated with a statistically significant difference in 30-day mortality compared with TAV-in-SAV (OR 0.71, 95% CI 0.25–2.00), nor in 1-year mortality (OR 1.02, 95% CI 0.47–2.18). TAV-in-TAV was associated with lower mean transvalvular gradients at 30 days (MD −2.71 mmHg, 95% CI −4.07 to −1.34).

A non-significant trend toward higher new permanent pacemaker implantation was observed after TAV-in-TAV (OR 1.85, 95% CI 0.94–3.65).</p>Conclusion<p>Current comparative evidence between TAV-in-TAV and TAV-in-SAV remains limited and observational. No definitive mortality difference was identified, but clinically meaningful benefit or harm cannot be excluded. TAV-in-TAV shows a consistent early haemodynamic signal with lower gradients, while the possible increase in pacemaker implantation remains exploratory.

These findings should be considered hypothesis-generating and require confirmation in larger prospective studies with longer follow-up.</p>Systematic Review Registration<p>crd.york.ac.uk/PROSPERO/view/CRD420261369410, PROSPERO CRD420261369410.</p>