The senescence-associated secretome for prediction of mortality in patients with aortic valve stenosis undergoing TAVR

Abstract

Abstract Background Cellular senescence is an essential mechanism in the process of aging. The senescence-associated secretory phenotype (SASP) includes mainly pro-inflammatory cytokines, proteases, soluble signalling factors, and growth modulators. Degenerative aortic valve stenosis (AVS) is the prototypical inflammatory age-related cardiovascular disease. Purpose Our aim was to assess whether circulating concentrations of SASP factors are associated with prognosis in elderly patients with AVS undergoing transcatheter aortic valve replacement (TAVR), the current standard therapy for severe cases. Methods A total of 24 SASPs were measured using the Luminex Multiplex ELISA Assay (Biotechene, GmbH) in 120 AVS patients undergoing TAVR between February 2017 and February 2020 with a prospective follow-up of up to 4 years. Receiver operating characteristic (ROC) curves were created for each SASP protein in order to identify predictive markers. SASPs were considered positive if their baseline value was above the cut-off value derived from ROC-curves. The only 3 independent predictive factors were selected to develop an easy-to-calculate score based on the number of positive SASP proteins (0 to 3). Primary endpoint was long-term all-cause mortality. Results Median (IQR) age of the population was 83.2 (78.9-87.0) years, 56.7% were women. According to ROC curves, 9 out of 24 SASPs showed a significant area under the curve (AUC), with values above 0.623 (see Table). Only 3 of the markers reflecting potentially different underlying mechanisms remained independent predictors, after including all SASP factors in a Cox Regression analysis: GDF-15, ICAM-1 and Osteoprotegerin (all, p<0.03). A score based on the number of baseline factors being above the AUC-derived threshold level showed an excellent discrimination ability to predict survival, with long-term all-cause mortality substantially increasing for each additional positive marker (see Kaplan-Meier curves). Conclusion In conclusion, the presence of elevated baseline levels for 0, 1, 2, or 3 of the independent SASP factors reflecting different underlying pathophysiological mechanisms predicts increased long-term all-cause mortality with profoundly improved discrimination power in AVS patients undergoing TAVR. If confirmed in further prospective studies, a combination of these 3 SASP markers could serve as a highly useful risk stratification tool in the elderly population with AVS.