Personalized absolute benefit of statin treatment for primary or secondary prevention of vascular disease in individual elderly patients.

OBJECTIVE

To estimate the absolute treatment effect of statin therapy on major adverse cardiovascular events (MACE; myocardial infarction, stroke and vascular death) for the individual patient aged ≥70 years.

METHODS

Prediction models for MACE were derived in patients aged ≥70 years with (n = 2550) and without (n = 3253) vascular disease from the "PROspective Study of Pravastatin in Elderly at Risk" (PROSPER) trial and validated in the "Secondary Manifestations of ARTerial disease" (SMART) cohort study (n = 1442) and the "Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm" (ASCOT-LLA) trial (n = 1893), respectively, using competing risk analysis. Prespecified predictors were various clinical characteristics including statin treatment. Individual absolute risk reductions (ARRs) for MACE in 5 and 10 years were estimated by subtracting on-treatment from off-treatment risk.

RESULTS

Individual ARRs were higher in elderly patients with vascular disease [5-year ARRs: median 5.1 %, interquartile range (IQR) 4.0-6.2 %, 10-year ARRs: median 7.8 %, IQR 6.8-8.6 %] than in patients without vascular disease (5-year ARRs: median 1.7 %, IQR 1.3-2.1 %, 10-year ARRs: 2.9 %, IQR 2.3-3.6 %). Ninety-eight percent of patients with vascular disease had a 5-year ARR ≥2.0 %, compared to 31 % of patients without vascular disease.

CONCLUSIONS

With a multivariable prediction model the absolute treatment effect of a statin on MACE for individual elderly patients with and without vascular disease can be quantified. Because of high ARRs, treating all patients is more beneficial than prediction-based treatment for secondary prevention of MACE. For primary prevention of MACE, the prediction model can be used to identify those patients who benefit meaningfully from statin therapy.