Sex differences in the effectiveness of statins after myocardial infarction

We sought to investigate the sex differences in the effectiveness of statins in patients with acute myocardial infarction (AMI).

Linking hospital discharge and drug claims databases from Quebec, Canada (1998-2004), we identified statin users (n = 14 710) and non-users (n = 23 833) discharged from hospital after an AMI-related hospital stay and followed up for as long as 7 years.

All-cause death rates were 4.1 and 14.6 per 100 person-years among users and non-users, respectively, whereas cardiac death rates were 2.2 and 7.4 per 100 person-years. For death from any cause, the adjusted hazard ratios associated with statin use in women were 0.61 (95% confidence interval [CI], 0.54-0.69) within 1 year of follow-up, 0.55 (0.48-0.63) at 1-3 years and 0.38 (0.31-0.49) at > 3 years; in men, the corresponding estimates were 0.54 (0.48-0.60), 0.48 (0.42-0.55) and 0.34 (0.30-0.39). For cardiac-related death, the adjusted hazard ratios associated with statin use in women were 0.70 (0.60-0.81) within 1 year, 0.56 (0.46-0.68) at 1-3 years and 0.44 (0.31-0.62) at > 3 years of follow-up, whereas in men, the estimates were 0.59 (0.51-0.69), 0.47 (0.39-0.58) and 0.37 (0.30-0.45), respectively.

Statin therapy after an AMI was associated with reduced rates of all-cause and cardiac mortality. The effect increased with time in both sexes, but the degree of risk reduction was less for women than for men.