*4.1.6 Acute coronary syndrome (ACS)*

A study in 7152 post-ACS patients showed that optimal adherents (PDC ≥ 75%) to any combination of antiplatelets, statins, BBs, and ACEIs/ARBs led to a significant reduction in cardiovascular risks (HR 0.80, 95% CI 0.73–0.88) than suboptimal adherents for all medications, except BBs alone [54]. Adherence to 2 or 1 drug significantly increased mortality risk compared with adherents to 4 or 3 (for two drugs: HR 1.2, 95% CI 1.0–1.3, *P* < 0.05; for 1 drug: HR 1.5, 95% CI 1.2–1.8, *P* < 0.05) [54].
