According to the American Heart Association’s 2004 statistical update, as many as 13,200,000 Americans had
coronary heart disease (CHD)
in 2001. Of these, 7,800,000 experienced a
, and of these, 184,757 died as a result.
CHD occurs when atherosclerotic plaques (layers of fat and cells) begin to build up and narrow or block your coronary arteries, which supply blood to your heart muscle. If not treated, these plaques may rupture leading to a clot and subsequent heart attack. Numerous studies have shown that lowering your LDL level can reduce your risk of developing
. In fact, the correlation is direct; the lower your LDL cholesterol, the lower your risk.
To help us all lower our risk for CHD, the American Heart Association (AHA) has published the following recommendations for LDL cholesterol levels:
People without CHD and with fewer than two risk factors
190 mg/dL*(4.9 mmol/L) or higher
160 mg/dL (4.1 mmol/L) or lower
People without CHD and with two or more risk factors
160 mg/dL (4.1 mmol/L) or higher
130 mg/dL (3.4 mmol/L) or lower
People with CHD
130 mg/dL (3.4 mmol/L) or higher
100 mg/dL (2.6 mmol/L) or lower
*mg/dL = milligrams per deciliter (mmol/L=millimoles per liter)
For some, a diet low in saturated fat and cholesterol, regular exercise, and a weight management program is enough to reduce their LDL cholesterol level to within the desirable range. For many, however, medications (generally a class of drugs called statins) are also prescribed.
But what about those at the highest risk, patients with CHD who have already experienced an acute coronary syndrome (a heart attack or imminent risk of a heart attack)? How low should LDL cholesterol levels go among these patients? Recently, a group of researchers set out to answer this question. They compared the effects of standard lipid-lowering therapy using pravastatin (a commonly used statin) with the effects of intensive lipid-lowering therapy using atorvastatin (a more powerful statin).
The results of their study were presented this past Monday in New Orleans at the annual scientific meeting of the American College of Cardiology and will be published in the April 8, 2004 issue of the
New England Journal of Medicine.
The study found that among patients with a history of acute coronary syndromes, intensive lipid-lowering therapy offers more protection against death or a second major cardiovascular event that does standard lipid-lowering therapy.
About the Study
The researchers enrolled 4,162 patients, all of who had been hospitalized for an acute coronary syndrome within the past 10 days. Each participant was randomized to receive either standard lipid-lowering therapy with 40 mg of pravastatin or intensive lipid-lowering therapy with 80 mg of atorvastatin.
The researchers compared the efficacy of the two therapies by measuring the length of time that passed between the time the therapy was started and the occurrence of any of the following events: death from any cause, heart attack, unstable angina (chest pain) requiring hospitalization, need for an invasive procedure to restore blood flow to the heart (revascularization) or stroke.
The researchers found that the LDL cholesterol levels of the participants who received standard lipid-lowering therapy were reduced to 95 mg/dL (2.5 mmol/L), while the LDL cholesterol levels of the participants who received intensive lipid-lowering therapy were reduced to 62 mg/dL (1.6 mmol/L).
They also found that over the course of the two-year study, 22.4% of the participants who received intensive lipid-lowering therapy experienced heart attack, unstable angina requiring hospitalization, revascularization, stroke, or death from any cause. This, when compared to the 26.3% event rate experienced by the participants who received the standard lipid-lowering therapy, represents a 16% reduction in the risk of a second serious coronary event.
How Does This Affect You?
The researchers concluded that among patients with a history of a major coronary event due to CHD, intensive lipid-lowering therapy offers greater protection than standard lipid-therapy against death or a second major coronary event. This benefit was seen as early as 30 days into the study and remained consistent throughout. It appears, therefore, that these patients would benefit from early and intensive reduction of LDL cholesterol to levels substantially lower than the current recommended guidelines.
According to this important study, lowering LDL-cholesterol to levels unseen in any industrial society is beneficial to patients with clinical CHD. It is hard to imagine that anyone could reasonably hope to achieve so low a cholesterol level through diet and exercise alone. Cardiologists, therefore, are quite likely to begin recommending intensive cholesterol-lowering drug therapy to their CHD patients.
What does it mean for individuals who are at risk for CHD, but have not become seriously ill? This study did not address that question, and it is unlikely that doctors will change their prescription practices for these patients. Despite the demonstrated power of some of these statin medications, they are not without their adverse effects. For most individuals, therefore, the best way to reduce CHD risk is still the medication-free approach of low-fat diets and regular exercise. However, if your cholesterol levels do not adequately respond, it is important to talk about medication treatment with your doctor, particularly if you have more than one risk factor for CHD.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a