Clinical Efficacy and Safety of Achieving Very Low LDL With Evolocumab (FOURIER Secondary Analysis)

How low is too low for LDL cholesterol? This analysis of FOURIER pushed the question to its extreme — and found no floor.

Among nearly 26,000 patients, the cardiovascular benefit of LDL lowering continued steadily down to remarkably low levels — below 0.2 mmol/L (under 8 mg/dL) — with no plateau and no sign of a harmful “J-curve.” Roughly 10 percent of patients reached LDL under 19 mg/dL. Crucially, achieving these very low levels showed no association with serious adverse events, neurocognitive problems, new diabetes, or any of ten pre-specified safety concerns over more than two years.

The finding directly addressed a longstanding fear that driving LDL very low might be dangerous. It supports treating high-risk patients well below conventional targets, reinforcing the “lower is better” principle with concrete safety reassurance at the extremes.

We rate the evidence strong. A pre-specified analysis of a large randomized trial, it is high-quality evidence — bounded only by its roughly two-year follow-up, which cannot speak to effects over decades.