NEW YORK (Reuters Health) – The institution of lipid-lowering therapy has significantly reduced mortality in patients with homozygous familial hypercholesterolemia (FH), researchers from South Africa report in the October 10th online Circulation.

“The study confirms the remarkable benefit of statin therapy even in this group of patients with the most severe degree of hypercholesterolemia,” Dr. Frederick J. Raal from University of the Witwatersrand, Johannesburg, South Africa told Reuters Health in an email. “High doses (of) statin therapy in these patients, even when started in these patients from as young as the age of two years, is remarkably safe and effective.”

Although about 1 in 500 people have the less severe heterozygous form of FH, only 1 in 1 million people have the more severe homozygous form. Besides adhering to a low-fat diet, modern treatment includes statins and cholesterol absorption inhibitors.

Dr. Raal and colleagues investigated all-cause and cardiovascular mortality in 149 homozygous FH patients, comparing results from pre-1990, when effective lipid-lowering drugs were not widely available, to post-1990, when statins became the primary therapy for such patients.

Among 75 patients who had before and after data, modern lipid-lowering therapy was associated with 24.3% decreases in total cholesterol and 26.4% decreases in LDL cholesterol.

Despite these seemingly small reductions, survival analysis demonstrated 66% reduction in the likelihood of death (P=0.02) and 51% reduction in the endpoint of major adverse cardiovascular events (MACE) (P=0.07).

Results were similar after exclusion of 23 patients who had received LDL apheresis or plasma exchange as part of their treatment.

“Statin therapy has prolonged the lives of our homozygous FH patients by nearly 30 years and prolonged the time to their first cardiovascular event by about 15 years,” Dr. Raal said. “There is no other class of medication that can match this remarkable achievement.”

“Acute coronary care (thrombolytics for acute events, coronary angioplasty, and improved surgical procedures, e.g., coronary bypass surgery, aortic valve replacement) may have also contributed to their increased survival,” Dr. Raal conceded. “However, the time to their first cardiovascular event or the need for bypass surgery has been markedly prolonged so I feel this contribution is minor.”

“Our subjects with homozygous FH are aware of the seriousness of their condition,” Dr. Raal explained. “They are careful with their diets, are not overweight, are not hypertensive, and none have diabetes. Smoking cigarettes may have increased their risk further in the past as some were smokers, but the majority have now quit.”

“The study highlights the importance of early initiation of lipid-lowering therapy, especially statin therapy, in patients with homozygous FH and in fact in all patients with familial hypercholesterolemia or at high risk for atherosclerosis,” Dr. Raal concluded.

Three of the 7 authors disclose support from pharmaceutical companies that manufacture lipid-modifying agents, and the authors acknowledge “the generous support of Pfizer South Africa, which has provided atorvastatin to many of our homozygous FH patients for 15 years.”

Reference:

Reduction in Mortality in Subjects With Homozygous Familial Hypercholesterolemia Associated With Advances in Lipid-Lowering Therapy