In-depth, patient-level analysis of clinical events in the NOTION-2 trial

The Nordic Aortic Valve Intervention 2 (NOTION-2) trial was a randomised controlled trial (RCT) comparing transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) in young, low surgical risk patients with severe tricuspid (N=270) and bicuspid (N=100) aortic stenosis (AS)1. The primary endpoint of the trial − a composite of all-cause mortality, stroke or rehospitalisation at 12 months − was comparable in tricuspid AS patients (TAVI: 8.7% vs SAVR: 8.3%; hazard ratio [HR] 1.0, 95% confidence interval [CI]: 0.5-2.3) but differed significantly in those with bicuspid AS (TAVI: 14.3% vs SAVR: 3.9%; HR 3.8, 95% CI: 0.8-18.5). These findings can only be considered hypothesis-generating owing to the relatively small sample size, but they raise important concerns as indications for TAVI expand to include younger patients in whom bicuspid AS is more frequently encountered. To address these concerns, we conducted an in-depth, patient-level analysis of individual trial participants who experienced cardiovascular (CV) mortality or stroke following either TAVI or SAVR (Figure 1), evaluating clinical characteristics, anatomical features determined from the preprocedural computed tomography (CT), and procedural...