A study led by Dr. Ilse Luirink published in the New England Journal of Medicine showed that initiating statins in children with familial hypercholesterolemia slowed the progression of carotid intima-media thickness and reduced the risk of cardiovascular disease in adulthood.
Familial hypercholesterolemia is a common autosomal dominant disorder that leads to abnormal lipoprotein metabolism. This ultimately leads to abnormal low-density lipoprotein (LDL) elevation from birth onwards and is associated with an increased risk of premature cardiovascular events. Currently, statins are the mainstay of treatment and typically started early in childhood. However, there is a lack of data that evaluates whether initiating a statin early in childhood lowers cardiovascular risk in adulthood. The investigators aimed to address this current gap in knowledge.
In the current study, the investigators aimed to compare the progression of both clinical cardiovascular disease and subclinical atherosclerosis in patients with familial hypercholesterolemia started on statin during childhood with those who were untreated and healthy control. Patients with familial hypercholesterolemia who were randomized in a previous study in 1997 to either statin or placebo were followed up. A total of 214 patients were enrolled, 210 of whom had a documented pathogenic mutation encoding the LDL receptor or apolipoprotein B. 95 unaffected siblings were also enrolled at baseline. 20 years after the initial study, the patients were contacted and invited to participate in this follow-up study. Those who were unable to come for a follow-up visit were contacted by phone to determine if they had any of the outcomes of interest. The outcome of interest was defined as cardiovascular disease or death from a cardiovascular cause. Those event rates were compared to those of the patients’ affected parents. Sub-clinical atherosclerosis was assessed by comparing the carotid intima-media thickness with that of the patient’s unaffected siblings.
Of the original cohort of 214, 184 were seen for follow up. Additionally, data on cardiovascular events and death due to cardiovascular causes was available for 95% and 100% of the cohort population. The mean LDL cholesterol level at follow-up was 160.7 (32% decrease from baseline) mg per deciliter in patients with familial hypercholesterolemia and 121.9 (24% increase from baseline) mg per deciliter in the unaffected siblings. Of the 156 parents of patients followed up, 41 (26%) had a cardiovascular event before the age of 40 (as compared to the 1 out of 203 patients in the study) (1% vs 26%). Additionally, there was a higher proportion of parents who died from a cardiovascular cause as compared to patients in the initial study (7% vs 0%). Additionally, the mean progression of carotid intima–media thickness over the entire follow-up period was 0.0056 mm per year in patients with familial hypercholesterolemia and 0.0057 mm per year in siblings (mean difference adjusted for sex, −0.0001 mm per year; 95% confidence interval, −0.0010 to 0.0008).
This 20-year follow up study demonstrated that there was no significant difference in subclinical atherosclerosis when comparing patients with statins initiated during childhood with familial hypercholesterolemia with their unaffected siblings. Additionally, there was a higher incidence of cardiovascular events and mortality in patients with familial hypercholesterolemia started on a statin during childhood when compared to their affected parents. These results extend the findings of previous observational data that support the early use of statins in children with familial hypercholesterolemia. While this study does include long term data, it does have its limitations. For instance, the study is observational and cannot make any conclusions about causality. Regardless, the findings of this study support the use of statins early in childhood in children with familial hypercholesterolemia.