Compounding Benefits of Cholesterol-Lowering Therapy for Major Cardiovascular Events: Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined whether the cardiovascular benefits of cholesterol-lowering therapy compound over time — specifically, whether the relative risk reduction achieved per year of treatment increases with treatment duration beyond what short-term RCTs demonstrate.

The central finding: LDL-C lowering benefits are not fixed but compound over time. Relative risk reduction grew from approximately 12% in year 1 to 29% by year 7 of treatment. This pattern is consistent with Mendelian randomization estimates of lifetime exposure effects — genetic variants that lower LDL-C throughout life produce proportionally greater cardiovascular event reductions than the same magnitude of pharmacological lowering started in adulthood. Short-term RCTs underestimate the full magnitude of benefit from lifetime cholesterol lowering because they capture only the initial years of a long-term biological process.

The practical implication is significant for primary prevention decision-making. When evaluating whether to initiate statin therapy in a 45-year-old with intermediate risk, the relevant calculation is not only the 5-year NNT from a trial that enrolled older patients — it is the compounding benefit that accumulates over 20–30 years of treatment. Earlier initiation and longer treatment duration produce greater benefit than current guideline communications often convey.

This analysis supports primordial and primary prevention strategies in younger patients, where the compounding benefit of early cholesterol lowering is maximized.

We rate the evidence strong. A rigorous systematic review and meta-analysis demonstrating that cholesterol-lowering benefits compound over time — foundational evidence supporting earlier initiation and longer duration of primary prevention therapy than current short-term NNT calculations suggest.