RESUMO
Background: Despite being the most commonly performed valvular intervention, risk prediction for aortic valve replacement in patients with severe aortic stenosis by currently used risk scores remains challenging. The study aim was to develop a biomarker-based risk score by means of a neuronal network. Methods: In this multicenter study, 3595 patients were divided into test and validation cohorts (70% to 30%) by random allocation. Input variables to develop the ABC-AS score were age, the cardiac biomarker high-sensitivity troponin T, and a patient history of cardiac decompensation. The validation cohort was used to verify the scores' value and for comparison with the Society of Thoracic Surgery Predictive Risk of Operative Mortality score. Results: Receiver operating curves demonstrated an improvement in prediction by using the ABC-AS score compared to the Society of Thoracic Surgery Predictive Risk of Operative Mortality (STS prom) score. Although the difference in predicting cardiovascular mortality was most notable at 30-day follow-up (area under the curve of 0.922 versus 0.678), ABC-AS also performed better in overall follow-up (0.839 versus 0.699). Furthermore, univariate analysis of ABC-AS tertiles yielded highly significant differences for all-cause (p < 0.0001) and cardiovascular mortality (p < 0.0001). Head-to-head comparison between both risk scores in a multivariable cox regression model underlined the potential of the ABC-AS score (HR per z-unit 2.633 (95% CI 2.156-3.216), p < 0.0001), while the STS prom score failed to reach statistical significance (p = 0.226). Conclusions: The newly developed ABC-AS score is an improved risk stratification tool to predict cardiovascular outcomes for patients undergoing aortic valve intervention.
RESUMO
Natriuretic peptide plasma levels help to manage patients with severe aortic stenosis (AS). The role of troponin plasma levels in this patient cohort remains speculative. A consortium of 4 university hospital centers in Austria analyzed retrospectively 3,595 patients admitted for valve replacement because of severe AS since 2007. The aim was to compare the additive preprocedural value of high-sensitivity troponin T (hsTnT) to N-terminal pro brain natriuretic peptide (NT-proBNP) plasma levels in predicting postoperative long-term survival in a large cohort undergoing either surgical (57.8%) or transcatheter (42.2%) aortic valve replacement. During a median follow-up of 2.93 (1.91 to 4.92) years, 919 patients (25.6%) died, in them 556 (15.5%) due to cardiovascular causes. Both normal hsTnT (<14 ng/l) and NT-proBNP (within age- and sex-corrected normal range) plasma levels were found in 481 patients (14.3%, group 1). Normal hsTnT but elevated NT-proBNP plasma levels were found in 748 patients (22.3%, group 2). Elevated hsTnT but normal NT-proBNP plasma levels were found in 258 patients (7.7%, group 3). Both elevated hsTnT and elevated NT-proBNP plasma levels were found in 1,869 patients (55.7%, group 4). Using Log Rank tests for comparison there was a highly significant difference in both cardiovascular mortality (p <0.0001) and all-cause mortality (p <0.0001). All-cause mortality rates after 1, 3, and 5 years were 2.1%, 5.4%, 7.7% in group 1; 4.0%, 7.5%, 11.5% in group 2; 5.8%, 8.9%, 14.0% in group 3; and 12.3%, 22.6%, 28.4% in group 4. In conclusion, hsTnT adds additional impact to NT-proBNP as a routinely available biomarker for risk stratification concerning postoperative survival in patients with severe AS admitted for valve replacement. The present study supports the concept to integrate hsTnT plasma levels in the management of severe AS.
