Ezetimibe Added to Statin Therapy After Acute Coronary Syndromes (IMPROVE-IT)

IMPROVE-IT settled a question that had hung over cholesterol treatment for years: does lowering LDL with a non-statin drug also reduce events, or is the benefit somehow unique to statins?

More than 18,000 patients recovering from an acute coronary syndrome were randomized to simvastatin alone or simvastatin plus ezetimibe. Adding ezetimibe drove LDL down further — from about 70 to 54 mg/dL — and that extra lowering produced a real, if modest, reduction in cardiovascular events, with an absolute 2-percentage-point benefit driven by fewer heart attacks and strokes.

Two principles emerged, both consequential. First, LDL lowering helps even at levels well below the old targets — there is benefit in going lower. Second, and more fundamental, the benefit is about the LDL reduction itself, not the statin: a different mechanism that lowers LDL delivers the expected payoff. This validated the entire strategy of adding non-statin agents like ezetimibe and, later, PCSK9 inhibitors.

We rate the evidence very strong. A large, long randomized trial, IMPROVE-IT is a pillar of the “lower is better, by any mechanism” understanding of LDL.