Study Identifies Characteristics of FH in Children and Adolescents

Familial hypercholesterolemia (FH) in children and adolescents has not been well described, but an analysis of registry data provides a clearer picture of the characteristics of youth with FH. The findings indicate that the prevalence of cardiovascular risk factors is high in this population and that efforts to attain treatment goals should be increased.

Sarah De Ferranti, MD, director of the Preventive Cardiology Clinic at Boston Children’s Hospital, presented the results at the Scientific Sessions of the American Heart Association held November 12 to 16, 2016, in New Orleans, LA. Emily O'Brien, PhD, Matthew T. Roe, MD, and Peter Shrader, MS, from Duke were also involved in the study.

FH is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). In the United States, FH affects approximately 1 in 250 individuals, many of whom are unaware they have the disease until they experience an acute cardiovascular event. Early treatment can help reduce the risk of atherosclerotic cardiovascular disease.

The trial was a cross-sectional analysis of data from children and adolescents who were enrolled in the Cascade Screening for Awareness and Detection of FH (CASCADE FH) registry from 9 US lipid clinics between April 2014 and February 2016.

The FH Foundation created the CASCADE FH registry in 2013 to address the lack of awareness of the condition. Data on both children and adults are maintained in the registry. Clinicians are the primary source of enrollees, but patients can also self-enroll.

To be considered for the current analysis, youth had to be below the age of 18 years and have heterozygous FH. Centralized data coordination for the study was carried out at Duke.

The researchers identified 334 children and adolescents with heterozygous FH in the registry. The median age at the time of FH diagnosis was 9 years, which was “arguably late,” according to De Ferranti. She noted that guidelines recommend that screening begin at 2 years for high-risk children and at 9 to 11 years for all children. Guidelines also recommend that lipid-lowering therapy begin at 10 years of age.

Nearly one-third of the youth had a family history of premature myocardial infarction; approximately 44% had at least 1 cardiovascular risk factor in addition to a high LDL-C level; 34% had 1 additional risk factor; and 10% had 2 additional risk factors.

De Ferranti reported that 59% of the children and adolescents in the study were receiving lipid-lowering therapy at the time of enrollment. Statins represented the most common treatment, with this class of drugs being used more often in children aged 10 years and older than in younger children (61% vs 12%).

LDL-C goals were achieved in 26% of the 197 youth receiving lipid-lowering therapy at the time of enrollment. The rate was higher among children 10 years or older than it was in younger children (Table).

Table. Achievement of LDL-C Goals

Goal Overall (N = 197),
n (%)
Age < 10 y (n = 29),
n (%)
Age  ≥  10 y (n = 168),
n (%)
LDL-C < 130 mg/dL at enrollment 44 (22) 1 (3) 43 (26)
 ≥ 50% change in LDL-C 29 (15) 1 (3) 28 (17)

LDL-C = low-density lipoprotein cholesterol.

Achievement of LDL-C goals was defined as an LDL-C level of less than 130 mg/dL at the time of enrollment in the registry or a reduction in the LDL-C level of at least 50%. 

“Opportunities exist to optimize the treatment of youth with FH to reduce their risk of cardiovascular disease,” De Ferranti concluded.

Source: De Ferranti S, O’Brien EC, Kindt I, et al. Pediatric familial hypercholesterolemia: children and adolescents enrolled in the Cascade Screening for Awareness and Detection registry.  Presented at: American Heart Association Scientific Sessions 2016; November 12-16, 2016; New Orleans, LA. Abstract 663.