The Heart Protection Study (HPS), provides new insights into the effects of statin therapy in certain subgroups, including the elderly, women, and those with low LDL.
John A. Farmer, MD, with Baylor College of Medicine, Houston, Texas, and Antonio M. Gotto, Jr., MD, DPhil, with Cornell University, New York, United States discuss, in their article, the findings of the HPS as they apply to these subgroups.
Statins decrease levels of cholesterol by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase. Trials evaluating these agents have demonstrated their efficacy, but the benefit of using them in certain subgroups has been uncertain.
The HPS study, reported in 1999, "took a novel approach to patient randomisation involving decision-making by both the physician and the patient," Dr. Farmer and Dr. Gotto, Jr., note. "If the physician thought a participant’s lipid profile offered compelling evidence either for or against statin therapy, the patient was excluded from the study."
Included in the HPS were 15,454 men and 5,082 women, aged 40 to 80 years, who were at elevated risk of coronary heart disease death. Patients were randomised to receive simvastatin (40 mg daily) or placebo and, in a ‘2×2 factorial’ design, antioxidant vitamins (600 mg vitamin E, 250 mg vitamin C and 20 mg beta-carotene daily) or placebo. Participants were followed for at least 5 years.
In their discussion of the trial results, Drs. Farmer and Gotto, Jr., note that antioxidant therapy demonstrated no effect on morbidity and mortality in the HPS trial and that investigators have yet to define the precise interaction of antioxidation and statin therapy.
In contrast, statin treatment significantly decreased the risk of cardiovascular morbidity and mortality (primary endpoint) and "any major vascular event," including non-fatal myocardial infarction, stroke, and need for revascularisation procedures (secondary endpoints).
In older adults compared to younger adults, the HPS trial found similar statin benefits, with about a 25% reduction in major vascular events regardless of age. "Older chronologic age alone, therefore, should not exclude patients from receiving therapy," they suggest.
The 5,082 women included in the HPS also demonstrated a similar reduction in vascular events compared to men, " suggesting a beneficial role of aggressive statin therapy regardless of sex."
Finally, statins also appeared to benefit those with low LDL cholesterol levels at randomisation. A total of 6,793 individuals had LDL cholesterol levels <116 milligrams per decilitre, and the use of simvastatin in this subgroup produced similar benefit as it did in those with higher levels (116 to 134 and > 135 milligrams per decilitre). "This finding refutes the concept of "a threshold below which decreasing LDL cholesterol levels is of no benefit," the authors suggest.
Dr. Farmer and Dr. Gotto, Jr., conclude that the HPS raises important questions for the future of CAD prevention, such as (1) "what are the optimal goals of therapy (2) is high coronary risk all that is needed to prompt the initiation of a statin" And (3) "who should qualify for treatment"
"Discussion of these issues will likely provide new insights into the optimal management of coronary risk," they add. Am J Cardiol 2003;92:1A:3i-9i.
Breakthrough in Diabetes Education for Children
dbaza inc. has created a product can help you use your education time more effectively, allowing you to spend your time on the more difficult issues. More Information