PCSK9 and aortic stenosis: Lipoprotein(a) (Lp(a)) has been established as an independent, likely causal risk factor for incident AS.4–6 Interventions aimed at lowering Lp(a), including proprotein convertase subtilisin/kexin type 9 inhibitors and apolipoprotein(a) antisense therapies, may be effective in delaying or preventing AS progression.7 However, the optimal timing of medical intervention in AS remains unresolved.