Transcatheter Aortic Valve Implantation: Risk Assessment and Clinical Outcome

Sammanfattning: Abstract
Background: Transcatheter aortic valve implantation (TAVI) has emerged as a treatment for patients with aortic stenosis (AS) and high surgical risk. To date, reports of short- and mid-term survival have been favourable. The aim of this thesis was to evaluate early safety, risk assessment and late survival following TAVI.
Methods: In this work we studied clinical outcome, prediction of 30-day mortality and acute kidney injury and late renal dysfunction following TAVI. In paper I and IV, a comparisons to propensity score matched patients undergoing AVR were made.
Results: The 30-day mortality following TAVI and AVR was 4.2% and 4.8% respectively (p=0.81); however, significant differences were seen in corresponding rates of survival (51.7±5.8% vs 72.3±4.3%; p<0.001) and in cumulative re-hospitalizations for congestive heart failure (CHF) (41.3±7.2% vs 23±4.3%; p=0.006) over a 4-year period. Postoperative AKI was diagnosed in 33% following TAVI and renal function remained impaired at 1 year of follow-up. The observed/expected mortality ratio was 0.16 for logistic EuroSCORE, 0.56 for STS score, and 0.52 for EuroSCORE II. The AUC was 0.69 (95% CI 0.54–0.84) for the logistic EuroSCORE, 0.60 (95% CI 0.38–0.82) for the STS score, and 0.66 (95% CI 0.46–0.86) for the EuroSCORE II.
Conclusions: The results of this thesis confirm the merit of TAVI in high risk patients with AS, although late outcome with TAVI proved inferior to that of AVR in propensity score matched patients. In our view, the relationship between TAVI and AVR appears to be complementary rather than substitutive. Furthermore, more accurate risk assessment tools are needed.