Most Heart Attack Patients' Cholesterol Levels Did Not Indicate Cardiac Risk

A new national study has shown that nearly 75 percent of patients hospitalized for a heart attack had cholesterol levels that would indicate they were not at high risk for a cardiovascular event, according to current national cholesterol guidelines.

Specifically, these patients had low-density lipoprotein (LDL) cholesterol levels that met current guidelines, and close to half had LDL levels classified in guidelines as optimal (less than 100 mg/dL).

"Almost 75 percent of heart attack patients fell within recommended targets for LDL cholesterol, demonstrating that the current guidelines may not be low enough to cut heart attack risk in most who could benefit," said Dr. Gregg C. Fonarow, Eliot Corday Professor of Cardiovascular Medicine and Science at the David Geffen School of Medicine at UCLA and the study's principal investigator.

While the risk of cardiovascular events increases substantially with LDL levels above 40–60 mg/dL, current national cholesterol guidelines consider LDL levels less than 100–130 mg/dL acceptable for many individuals. The guidelines are thus not effectively identifying the majority of individuals who will develop fatal and non-fatal cardiovascular events, according to the study's authors.

Researchers also found that more than half of patients hospitalized for a heart attack had poor high-density lipoprotein (HDL) cholesterol levels, according to national guidelines.

Published in the January issue of the American Heart Journal, the study suggests that lowering guideline targets for LDL cholesterol for those at risk for cardiovascular disease, as well as developing better treatments to raise HDL cholesterol, may help reduce the number of patients hospitalized for heart attack in the future.

"The study gives us new insight and intervention ideas to help reduce the number of heart attacks," said Fonarow, who is also director of the Ahmanson–UCLA Cardiomyopathy Center.

"This is one of the first studies to address lipid levels in patients hospitalized for a heart attack at hospitals across the entire country."

The research team used a national database sponsored by the American Heart Association's Get with the Guidelines program. The database includes information on patients hospitalized for cardiovascular disease at 541 hospitals across the country.

Researchers analyzed data from 136,905 patients hospitalized for a heart attack nationwide between 2000 and 2006 whose lipid levels upon hospital admission were documented. This accounted for 59 percent of total hospital admissions for heart attack at participating hospitals during the study period.

Among individuals without any prior cardiovascular disease or diabetes, 72.1 percent had admission LDL levels less than 130 mg/dL, which is the current LDL cholesterol target for this population. Thus, the vast majority of individuals having their first heart attack would not have been targeted for effective preventative treatments based on the criteria used in the current guidelines.