Background: The prognostic value of cardiac damage staging classification based on the extent of extravalvular damage has been proposed in moderate/severe aortic stenosis (AS)., Objectives: The purpose of this study was to assess the association of cardiac damage staging with mortality across the spectrum of patients with AS following aortic surgical or transcatheter aortic valve replacement (AVR)., Methods: We conducted a pooled meta-analysis of Kaplan-Meier-derived reconstructed time-to-event data from studies published through February 2023., Results: In total, 16 studies (n = 14,499) met our eligibility criteria and included 12,282 patients with symptomatic severe AS and 2,217 patients with asymptomatic severe/moderate AS. For patients with symptomatic severe AS, all-cause mortality was 24.0%, 27.7%, 38.0%, 56.3%, and 57.3% at 5 years in patients with cardiac damage stage 0, 1, 2, 3, and 4, respectively (stage 0 as reference; HR in stage 1: 1.30 [95% CI: 1.03-1.64]; P = 0.029; stage 2: 1.74 [95% CI: 1.41-2.16]; P < 0.001; stage 3: 2.92 [95% CI: 2.35-3.64]; P < 0.001, and stage 4: 3.51 [95% CI: 2.79-4.41]; P < 0.001). For patients with asymptomatic moderate/severe AS, all-cause mortality was 19.3%, 36.9%, 51.7%, and 67.8% at 8 years in patients with cardiac damage stage 0, 1, 2, and 3 to 4, respectively (HR in stage 1: 1.70 [95% CI: 1.21-2.38]; P = 0.002; stage 2: 2.20 [95% CI: 1.60-3.02]; P < 0.001; and stage 3 to 4: 3.90 [95% CI: 2.79-5.47]; P < 0.001)., Conclusions: In patients undergoing AVR across the symptomatic and severity spectrum of AS, cardiac damage staging at baseline has important prognostic implications. This pooled meta-analysis in patients undergoing AVR suggests that staging of baseline cardiac damage could be considered for timing and selection of therapy in patients with moderate or severe AS to determine the need for earlier AVR or adjunctive pharmacotherapy to prevent irreversible cardiac damage and improve the long-term prognosis., Competing Interests: Mr Xander Jacquemyn was supported by the Belgian American Educational Foundation. Dr Généreux has served as a consultant for Abbott Vascular, Abiomed, BioTrace Medical, Boston Scientific, CARANX Medical, Cardiovascular System Inc (PI Eclipse Trial), Edwards Lifesciences (PI EARLY-TAVR trial, PI PROGRESS trial), GE Healthcare, iRhythm Technologies, Medtronic, Opsens, Pi-Cardia, Puzzle Medical, Saranas, Shockwave, Siemens, Soundbite Medical Inc, Teleflex, and 4C Medical (PI feasibility study); has served as an advisor for Abbott Vascular, Abiomed, BioTrace Medical, Edwards Lifesciences, and Medtronic; has received speaker fees from Abbott Vascular, Abiomed, BioTrace Medical, Edwards Lifesciences, Medtronic, and Shockwave; has served as a proctor for and received an institutional research grant from Edwards Lifesciences, and has equity in Pi-Cardia, Puzzle Medical, Saranas, and Soundbite Medical Inc. Dr Pibarot has received funding from Edwards Lifesciences, Medtronic, Pi-Cardia, and Cardiac Phoenix for echocardiography core laboratory analyses and research studies in the field of transcatheter valve therapies, for which he received no personal compensation, and has received lecture fees from Edwards Lifesciences and Medtronic. The Cardiovascular Research Foundation (Dr Cohen and Leon) receives research funding from Edwards Lifesciences (no direct compensation). Dr Clavel holds a young investigator grant from the QHLI. Dr Gillam has served as a consultant for Edwards Lifesciences; and has core lab contracts with Edwards Lifesciences and Medtronic. Dr Sultan received institutional research support from Abbott, Artivion, Boston Scientific, Edwards, Medtronic, and Terumo Aortic. Dr Cohen has received research grant support and consulting income from Edwards Lifesciences, Medtronic, Boston Scientific, and Abbott. Dr Bax: The Department of Cardiology (LUMC, The Netherlands) has received research grants from Medtronic, Biotronik, Edwards Lifesciences, and Boston Scientific and has received speaker fees from Abbott Vascular and Edwards Lifesciences. Dr Leon serves on the PARTNER Trial Executive Committee for Edwards Lifesciences (nonpaid); has received institutional research grants from and has served as a nonpaid advisor for Abbott, Boston Scientific, and Medtronic; has served as a nonpaid advisor for Sinomed; and has equity in Medinol. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)