Early Valve Replacement vs Surveillance in Moderate Aortic Stenosis: Meta-Analysis of Randomized and Observational Evidence

BACKGROUND: Moderate aortic stenosis (AS) is associated with excess mortality, and 2 randomized trials have tested early transcatheter aortic valve replacement (TAVR). OBJECTIVES: The authors sought to estimate the effects of early TAVR vs clinical surveillance and to compare randomized with observational estimates. METHODS: Six databases and registries were searched through November 3, 2026. Adjusted observational studies were synthesized separately from trials. Certainty was rated with GRADE. RESULTS: Two trials (922 patients; TAVR UNLOAD, n = 178, HF with reduced ejection fraction; PROGRESS, n = 744, 96.4% symptomatic) and 7 cohorts were included. Early TAVR did not detectably change death over approximately 2 years (HR: 1.05; 95% CI: 0.74-1.49; low certainty), with one-fifth of the deaths needed to detect a 20% reduction. Heart failure (HF) hospitalization was lower (RR: 0.53; 95% CI: 0.36-0.77; low certainty), or 70 fewer patients per 1,000 at 2 years. New pacemakers were more frequent (PROGRESS: 17.3% vs 9.3%; moderate certainty). About half of surveillance patients underwent valve replacement within 2 years. Observational cohorts estimated a 48% mortality reduction (HR: 0.52; 95% CI: 0.43-0.64; very low certainty), which differed from the randomized estimate (ratio of HRs: 2.01; 95% CI: 1.37-2.95). CONCLUSIONS: In older, predominantly symptomatic patients with moderate AS, early TAVR may make little or no difference to 2-year mortality and may reduce HF hospitalization, at the cost of more pacemakers. Because about half of patients under surveillance receive a valve within 2 years, the decision largely concerns timing. Observational survival estimates should not guide practice.