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With high coronary calcium and high-risk family, statins may be helpful

NEW YORK (Reuters Health) – Statins appear to lower the odds of cardiovascular events in asymptomatic individuals with a family history of premature coronary artery disease and a very high coronary calcium score, according to a post hoc analysis from the St. Francis Heart Study.

“Family history can be used as a risk identifier to identify families at risk, and calcium scoring can then be used to identify which individuals within those families are at particular risk,” senior investigator Dr. Sara-Joan Pinto-Sietsma from the University of Amsterdam told Reuters Health in an email. “Our article finally shows that treatment of these individuals indeed results in a reduction in cardiovascular events.”

The original purpose of the St. Francis Heart Study, as explained in 2005 in the Journal of the American College of Cardiology, was to test the prognostic value of electron beam computed tomographic (CT) scanning to assess calcium levels in the coronary arteries. (Working with nearly 5,000 middle aged people, all apparently healthy at baseline, researchers concluded that the technology improves the prediction of cardiovascular outcomes, “independent of standard risk factors, more accurately than standard risk factors and CRP, and refines Framingham risk stratification.”)

Subsequently, participants with a coronary calcium score above the 80th percentile were invited to enroll in a randomized controlled trial comparing atorvastatin 20 mg, aspirin 81 mg, vitamin C 1 g, and vitamin 1000 U with aspirin 81 mg and matching placebo.

Altogether, that trial included 1,005 individuals, including 543 with a positive family history for premature coronary artery disease.

Last month in JACC: Cardiovascular Imaging, Dr. Pinto-Sietsma’s group reported that over a median follow-up of 4.3 years, in the group with a family history of premature disease, there were significantly fewer individuals with cardiovascular events among those who received atorvastatin instead of placebo (7.2% vs 12.5%).

Atorvastatin didn’t seem to have any effect in the patients with a negative history for premature coronary artery disease.

In Cox proportional hazards analyses, individuals with a positive family history had a 45% reduction in cardiovascular events, whereas there was no significant reduction in individuals with a negative family history. This was also true for coronary events and cardiovascular events beyond 90 days from study entry.

The effect of treatment was mainly driven by the 60% reduction in myocardial infarction among treated individuals with a positive family history, and correction for triglycerides or other possible confounders did not change the results.

In fact, exclusion of individuals already recommended for statin therapy increased the apparent benefit of treatment.

“We emphasize that this population was selected as those with coronary calcium score above the 80th percentile,” the researchers note. “The results should not be extrapolated to patients with lower coronary calcium scores; we believe that further study is needed in this area.”

“Since the St. Francis Heart study was designed as statins and vitamins on top of aspirin, we believe all these individuals should receive statins,” Dr. Pinto-Sietsma concluded. “Besides, since all individuals received aspirin, one cannot assume that aspirin treatment has no effect. Therefore, we also prescribe aspirin to our patients. Concerning vitamins, we believe the evidence for vitamins in reducing cardiovascular events is so limited that we do not prescribe vitamins.”

“While we await much-needed large-scale outcomes trials to better define the role of medical treatment(s) differentially applied according to cardiac computed tomography measures of risk, in patients with advanced subclinical coronary atherosclerosis, many of us will continue to reach for statins and aspirin,” writes Dr. Todd C. Villines from Walter Reed National Military Medical Center, Bethesda, Maryland in a related editorial. “If unsure, then perhaps take a good family history to help you and your patient decide.”

The original St. Francis Heart Study was funded by the St. Francis Hospital Foundation. Pfizer Inc. provided atorvastatin and matching placebo free of charge but played no role in study design; in the collection, analysis, and interpretation of data; or in the preparation or submission of this report.

SOURCE: http://bit.ly/IEFlIB

J Am Coll Cardiol Img 2012;5:252-260,261-263.