Beyond Lp(a)HORIZON: Rethinking Lipoprotein(a)-Associated Risk and Looking Beyond Atherosclerosis. A negative result that calls for a biological, rather than simplistic, interpretation

The preliminary results of the Lp(a)HORIZON trial call for a critical reappraisal of the role of lipoprotein(a) [Lp(a)] in cardiovascular disease and, above all, of the conditions under which lowering Lp(a) may translate into clinical benefit. According to the topline communication released on September 4, 2026, pelacarsen significantly reduced Lp(a) concentrations, but the trial did not meet its primary endpoint, a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and urgent coronary revascularization in patients with established cardiovascular disease and elevated Lp(a). Pending full presentation of the results, this finding should be interpreted cautiously. A neutral result from a single pharmacological intervention does not necessarily disprove a causal role for Lp(a). Rather, it may indicate that the relationship between biomarker level, metabolic context, duration of exposure, timing of intervention, and therapeutic benefit is more complex than initially assumed. The hazard ratio and its confidence interval, the absolute and relative magnitude of Lp(a) lowering, the timing of curve separation, treatment adherence, and prespecified analyses according to Lp(a), LDL-C, and apolipoprotein B will be essential for interpretation