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Familial hypercholesterolemia is not rare
A colleague of mine was doing an outreach clinic and was asked to sign off on some lab results of the spouse of a patient he was seeing for diabetes that afternoon. The man’s LDL was 250 mg/dL; in the past it had been as high as 314 mg/dL. My colleague promptly arranged for him to come see me in consult.
The patient was 62 years old and had a history of myocardial infarctions, two six-vessel coronary bypass graft surgeries and multiple angioplasties. I was immediately struck by his tendon xanthomas which were the most prominent I have seen in some time. His primary care practitioner had diagnosed him with “rheumatoid arthritis.” For his hypercholesterolemia, he is on simvastatin monotherapy which is the only therapy on formulary at his clinic. Before my colleague had sent this patient my way, he was to see cardiology for management of hypercholesterolemia.
For some reason, familial hypercholesterolemia is thought of as being very rare. Although homozygous familial hypercholesterolemia is indeed rare, about one in 1 million, heterozygous familial hypercholesterolemia is much more common, occurring in about one in 500 of the general population.
Familial hypercholesterolemia is usually inherited as an autosomal dominant disorder. Thus, 50% of family members are at risk. This man’s family is no exception. Of his seven brothers, all are deceased from premature cardiovascular disease. The first one to die from MI was only 32 years old. The patient has two daughters who have been afflicted as well. One, age 32, has been told that her unusual physical exam findings are due to “arthritis” just like her father. He does not think his daughters are on lipid-lowering therapy or have been counseled about their future cardiovascular risk.
Despite my interest in lipid disorders, I rarely get consults for dyslipidemia from cardiology. Patients are sent to me for diabetes frequently, but almost never for lipids. When I mention my particular interest in familial lipid disorders, often I am told, “We don’t have any in our practice.” Once, when discussing the prevalence of familial hypercholesterolemia, I was told, “I’ve been in practice for 20 years and have never seen a case.”
I seriously doubt that. I am sure there are a number of patients in every cardiologist’s practice. Too many are undiagnosed. I reviewed the criteria for screening and diagnosing familial hypercholesterolemia in a previous post.
Treatment of familial hypercholesterolemia is challenging. Even with aggressive multidrug therapy, many patients have very high cholesterol. The underlying cause is defective LDL receptor. Until recently, there was little hope. However, in 1997, the FDA approved the use of LDL apheresis for the management of familial hypercholesterolemia refractory to medical management. I will review the specifics of LDL apheresis in a future post.
Unfortunately, most people with familial hypercholesterolemia do not know another treatment option is available. They undergo repeated cardiovascular interventions and assume that eventually they too will succumb to cardiovascular disease as so many of their family members have. However, it does not have to be this way. LDL apheresis can offer hope.
