Validation of transcatheter aortic valve implantation risk scores in relation to early and mid-term survival: a single-centre study.

Objectives: The aim of this study was to validate recently proposed risk scores for the prediction of mortality up to 1 year after transcatheter aortic valve implantation (TAVI), using a self-expandable valve (CoreValve).

Methods: In this single-centre study, 225 consecutive patients with severe symptomatic aortic valve stenosis, who underwent TAVI between December 2007 and January 2015, were included. Conventional surgical risk scores (logistic EuroSCORE, EuroSCORE II and STS score) were calculated as well as newly proposed TAVI risk scores (TAVI2-SCORe, STT Score and OBSERVANT score). Medium-term survival of the patients was assessed up to 1 year after TAVI.

Results: The median age was 82 (77-86) years and 45.3% were male. Patients were categorized into 'non-high risk' or 'high risk' according to logistic EuroSCORE >20%, EuroSCORE II >8%, STS score >10%, TAVI2-SCORe >2, STT score >12% and OBSERVANT score >6. Thirty-day and 1-year survival rates were significantly different between 'non-high-risk' and 'high-risk' patients according to the STS score (1 year: low: 84.4% vs high: 67.0%, P = 0.010) and according to OBSERVANT score (1 year: low: 85.2% vs high: 68.4%, P = 0.005). In contrast, TAVI2-SCORe and STT score did not discriminate 'non-high-risk' and 'high-risk' patients. This was confirmed by Cox regression analysis [STS score >10%: hazard ratio: 2.484 (1.206-5.115), P = 0.014; OBSERVANT score >6: hazard ratio: 2.532 (1.295-4.952), P = 0.007].

Conclusions: In this single-centre study, OBSERVANT and STS score most accurately predicted early and mid-term survival in patients undergoing TAVI, using a self-expandable valve (CoreValve).