Efficacy of statins in familial hypercholesterolaemia: a long term cohort study.

Objective: To determine the efficacy of statin treatment on risk of coronary heart disease in patients with familial hypercholesterolaemia.
Design: Cohort study with a mean follow-up of 8.5 years.
Setting: 27 outpatient lipid clinics.
Subjects: 2146 patients with familial hypercholesterolaemia without prevalent coronary heart disease before 1 January 1990.
Main Outcome Measures: Risk of coronary heart disease in treated and "untreated" (delay in starting statin treatment) patients compared with a Cox regression model in which statin use was a time dependent variable.
Results: In January 1990, 413 (21%) of the patients had started statin treatment, and during follow-up another 1294 patients (66%) started after a mean delay of 4.3 years. Most patients received simvastatin (n=1167, 33 mg daily) or atorvastatin (n=211, 49 mg daily). We observed an overall risk reduction of 76% (hazard ratio 0.24 (95% confidence interval 0.18 to 0.30), P<0.001). In fact, the risk of myocardial infarction in these statin treated patients was not significantly greater than that in an age-matched sample from the general population (hazard ration 1.44 (0.80 to 2.60), P=0.23).
Conclusion: Lower statin doses than those currently advised reduced the risk of coronary heart disease to a greater extent than anticipated in patients with familial hypercholesterolaemia. With statin treatment, such patients no longer have a risk of myocardial infarction significantly different from that of the general population.