Among 174,014 community-dwelling adults aged 75 and older without prior cardiovascular disease, baseline statin exposure was associated with a 19.5% lower hazard of incident acute myocardial infarction (HR 0.805; 95% CI 0.731–0.887) over a median five-year follow-up. The absolute risk difference was modest — 0.30 percentage points — yielding an observational number needed to treat of 338 over five years. Crucially, the protective signal persisted after Fine-Gray competing-risk regression accounting for all-cause mortality (sHR 0.823), and propensity-score matching was performed as an additional sensitivity analysis.
This finding carries real clinical weight. Primary prevention statin guidelines remain deeply ambiguous for adults over 75, largely because randomized trials have systematically excluded this age group. The Madrid cohort's scale — nearly 175,000 individuals, mean age 82.5 — makes it one of the largest observational datasets to directly address this gap. However, several limitations demand caution. Residual confounding is inherent to retrospective pharmacy-dispensing data; healthier patients may be systematically more likely to receive statins (healthy-user bias). The cohort excluded dementia, cancer, and advanced kidney disease, meaning results may not generalize to the frailest older adults. The NNT of 338 over five years also signals modest absolute benefit, requiring individualized risk-benefit discussions weighing polypharmacy and adverse effects. This is a preprint posted on medRxiv and has not yet undergone peer review — findings should be interpreted as hypothesis-strengthening rather than practice-changing until formal scrutiny is complete. Still, the evidence directionally supports reconsidering blanket statin de-prescribing in healthy octogenarians.