MI before age 50? Think familial hypercholesterolemia, substance abuse

April 26, 2018|Anticoagulation Hub

REPORTING FROM ACC 18

ORLANDO – Patients with an MI before age 50 commonly have familial hypercholesterolemia or a substance abuse issue, according to presentations at the annual meeting of the American College of Cardiology.

Not only is the prevalence of familial hypercholesterolemia (FH) increased in patients with an MI at a young age, but 1 year post MI, their LDL remains unacceptably high at 100 mg/dL or more in a high percentage of cases. For that matter, the same is true in patients with an MI before age 50 who don’t have FH, reported Ron Blankstein, MD, director of cardiac computed tomography at Brigham and Women’s Hospital and a cardiologist at Harvard Medical School, Boston.

FH patients after early MI

Dr. Blankstein presented a retrospective study of 1,996 adults with a first confirmed type 1 MI before at 50 who presented at Brigham and Women’s Hospital or Massachusetts General Hospital, of whom 9% met Dutch Lipid Clinic Network criteria for probable or definite FH.

The average age at the time of MI was 44 years. A family history of premature CAD was present in 72% of the FH group, compared with 26% of those without probable or definite FH. The mean LDL level was 180 mg/dL in the FH patients and 113 mg/dL in the non-FH early MI group.

Among patients with an MI before age 50 and a family history of premature CAD, the prevalence of FH was enriched, at 22%. Among those with an LDL of 160 mg/dL or more, the prevalence of FH rose further, to 36%. And by combining all three criteria – MI before age 50, a positive family history of early CAD, and an LDL of at least 160 mg/dL – the prevalence of FH shot up to 64%, Dr. Blankstein said.

Only 89% of patients with an MI prior to turning 50 years old were discharged on a statin. “That’s lower than I would have expected,” he said.

One year post MI, LDL levels had dropped by a mean of 79 mg/dL in the FH group and 39 mg/dL in the non-FH patients. This translated into a 45% reduction in the FH patients, a significantly greater decrease than the 34% drop in the non-FH group. Nonetheless, 43% of FH patients had an LDL of 100 mg/dL or greater at 1 year, as did 26% without FH. These are patients who are particularly likely to benefit from more aggressive lipid-lowering after an acute coronary syndrome. Given that almost 90% of patients with FH remain undiagnosed, assessment for the genetic disorder in young patients with MI is an important means of case finding, the cardiologist observed.