P4665High sensitivity troponin t and n-terminal pro brain natriuretic peptide plasma levels predict long-term postoperative survival in patients with severe aortic stenosis admitted for valve implantation
Authors: Barbieri F , Senoner T , Holfeld J , Semsroth S , Lambert T , Zweiker D , Theurl T , Rainer P P , Schmidt A , Feuchtner G M , Steinwender C , Hoppe U , Mueller S , Grimm M , Dichtl W 
Published: October 2019

Abstract

Aims
Optimal timing of valve implantation in patients with severe aortic stenosis (AS) is under debate, considering the subjective nature of symptom onset. We aimed to investigate the pre-procedural value of routinely available cardiac biomarkers in predicting postoperative long-term outcome in a large cohort undergoing either surgical or transcatheter aortic valve implantation.

Methods
The Tyrolean Aortic Stenosis Study-2 (TASS-2) group, a consortium of four university hospital centers in Austria, analysed pre-procedural high-sensitivity troponin T (hsTnT) and N-terminal pro brain natriuretic peptide (NT-proBNP) plasma levels in 3595 patients admitted for valve implantation because of severe aortic stenosis since 2007.

Results
Transcatheter aortic valve implantation was performed in 1517 (42.2%) of patients. During a median follow-up of 2.93 (1.91–4.92) years, 919 patients (25.6%) died, among them 556 (15.5%) due to cardiovascular causes. In multivariate cox regression analysis - adjusting for STS risk score (intermediate risk 4–8%, high risk >8%), degree of left ventricular systolic dysfunction (ejection fraction 30–50% and <30%), atrial fibrillation, sex, age, renal function, COPD, arterial hypertension, diabetes mellitus, concomitant significant coronary artery disease and type of procedure (surgical aortic valve replacement or transcatheter aortic valve implantation) - pre-procedural hsTnT as well as NT-proBNP plasma levels were strong independent predictors for postoperative survival: hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.07–3.11, P=0.028 for mildly to moderately elevated hsTnT (14–50 ng/l); HR 2.80, CI 1.61–4.89, P<0.001 for severely elevated hsTnT (>50 ng/l); HR 1.38, CI 1.06–1.81, P=0.018 for mildly to moderately elevated NT-proBNP (defined by an increase of up to threefold of age- and sex-corrected normal range); HR 1.68, CI 1.29–2.18, P<0.001 for severely elevated NT-proBNP (defined by an increase of more than threefold of age- and sex-corrected normal range). For direct comparison of these two biomarkers a second cox regression model was conducted including only hsTnT and NT-proBNP revealing the strength of hsTnT as a predictive biomarker: HR 2.20, 95% CI 1.29–3.77, P=0.004 for minimally elevated hsTnT (5–13.99 ng/l); HR 4.05, CI 2.41–6.82, P<0.001 for mildly to moderately elevated hsTnT (14–50 ng/l); HR 8.63, CI 5.07–14.70, P<0.001 for severely elevated hsTnT (>50 ng/l); HR 1.47, CI 1.13–1.91, P=0.004 for mildly to moderately elevated NT-proBNP; HR 1.96, CI 1.54–2.51, P<0.001 for severely elevated NT-proBNP.

Conclusion
hsTNT and NT-proBNP strongly predict long-term postoperative survival in patients with severe AS admitted for valve implantation.

Acknowledgement/Funding
This work was supported by the Tiroler Wissenschaftsförderung: grant number TWF-2017-1-5, GZ: UNI-0404-2104