Heart Talk - April 2019
New Guidelines on Aspirin for Heart Attack and Stroke Prevention: What Should You Do?
Heart-healthy and Stroke-free Living with Eric A. Goulder, MD, FACC
For decades, aspirin has been hailed as a panacea to prevent heart attacks and strokes, as well as some forms of cancer. Until recently, guidelines from leading medical groups, including the American Heart Association (AHA) and the American College of Cardiology (ACC), advised certain patients to take daily low-dose aspirin to avoid cardiovascular (CV) events — and about 40% of Americans over age 50 followed that advice.
In March, millions of Americans who take a baby aspirin a day to keep heart attacks and strokes away were alarmed by a flurry of headlines like these: “Experts now say daily aspirin could do more harm than good,” “Don’t take daily aspirin to prevent heart attacks and strokes,” and ”New Guidelines Advise Against Aspirin to Prevent Heart Attack, Stroke.” One media outlet advised “older patients” to “toss your baby aspirin,” without cautioning that patients should never quit any medically prescribed therapy without consulting their health provider. Here is a look at the new guidelines and key takeaways from the BaleDoneen Method for the prevention of heart attack, stroke and diabetes.
WHAT ARE THE CARDIOVASCULAR RISKS AND BENEFITS OF ASPIRIN?
Also known as acetylsalicylic acid (ASA), aspirin has proven anti-clotting effects, thus helping to prevent heart attacks and ischemic strokes, which occur when a clot blocks flow of blood to the heart or brain. However, ASA can also be dangerous due to a significant risk for internal bleeding.
More than 200 studies have shown that low-dose aspirin (75 to 100 mg. daily) significantly reduces risk for repeat heart attacks and strokes in patients who have already suffered one or more of these eves, with this potentially lifesaving benefit clearly outweighing the low, but serious, risk for bleeding linked to this drug. The efficacy of ASA for these patients remains undisputed, and guidelines recommending it for “secondary prevention” have not changed.
Aspirin use by patients who have not yet had a heart attack or stroke (defined as “primary prevention” by the standard of care) has long been controversial. As we recently reported, more than 30 years of randomized controlled trials (RCTs) — the gold standard of scientific research — have yielded conflicting findings about the risks, benefits and effectiveness of aspirin for these patients, leading to inconsistent guidelines from medical societies and government agencies in the U.S. and Europe, recommending for and against aspirin for “primary prevention.”
WHAT’S DIFFERENT ABOUT THE NEW GUIDELINES FOR ASPIRIN USE?
Issued by the AHA and ACC in March, the guidelines contain several new recommendations for healthcare providers for “primary prevention” of cardiovascular disease (CVD), the leading killer of Americans. For these patients, the primary prevention guidelines advise the following:
• Low-dose aspirin (75-100 mg. daily) might be considered for select adults ages 40 to 70 who are at increased risk for CVD, but not at increased risk for bleeding.
• Low-dose ASA should not be prescribed routinely for adults under age 70.
• Low-dose ASA should not be prescribed for patients of any age who are at increased risk for bleeding.
HOW TRUSTWORTHY ARE THESE GUIDELINES?
To decide which treatment would be most beneficial for people ages 40 to 75 who are being evaluated for CVD prevention, the guidelines recommend that clinicians to use a 10-year risk assessment estimation (such as the well-known Framingham Risk Score, or FRS) before prescribing medications, such as aspirin, cholesterol-lowering statins, or drugs for high blood pressure.
This is where the BaleDoneen Method differs from the standard of care. Because FRS and other risk estimation tools have been shown in many studies to be unreliable, patients at high risk for heart attacks and strokes can be missed because they don’t have the specific risk factors that these tools analyze. For example, a national study of more than 136,000 people hospitalized for heart attacks found that 75% had “normal” cholesterol levels and about half had “optimal” levels of LDL (bad) cholesterol.
As we recently reported, CVD in women is particularly likely to go undiagnosed and untreated. Sixty-four percent of women who die suddenly from a heart attack were previously unaware that they had CVD, which kills ten times more women each year than all forms of cancer combined. Recent studies also show that rates of heart attacks and strokes are on the rise in young adults (those under age 55), and in a study of heart attack survivors ages 18 to 55, only about half knew they were at risk before the event.
WHAT ARE THE BALEDONEEN TAKEAWAY ON ASPIRIN USE?
Unlike the standard of care, the BaleDoneen Method does not rely on risk-factor analysis alone. Our approach to prevention is based on a disease/inflammation paradigm in which all patients are considered “guilty” of harboring silent, deadly plaque in their arteries unless proven “innocent” through comprehensive laboratory and imaging testing, including carotid intima-media thickness (cIMT), an FDA-approved minute ultrasound scan of the neck’s largest arteries.
The AHA/ACC guidelines advise that to guide treatment decisions, including whether or not to prescribe ASA, for “select patients,” providers consider using a different imaging test called the coronary artery calcium score (CACS) to evaluate the person’s arterial health. While CACS is an excellent test, it can only detect calcified (stable) plaque, while cIMT can detect soft, vulnerable plaque (the most dangerous kind).
While we consider the inclusion of imaging in the guidelines an important step forward for the standard of care, we believe that the advice to limit it to select patients and base most decisions solely on risk factor estimates continues to leave millions of patients who have nontraditional risk factors — and silent, deadly plaque — in their arteries in potential peril.
Instead, we propose a precision-medicine, three-tiered approach that starts a comprehensive evaluation, including lab and vascular imaging tests. Patients would then be divided into three groups, based on the presence or absence of disease (plaque) as follows:
• Primary prevention. In the absence of arterial disease (plaque), the risk for a heart attack or stroke is so low that the benefits of ASA would be overshadowed by its potential harms. Instead, these patients should receive personalized therapies to reduce any potential risks they may have for future development of CVD, including genetic risks.
• Secondary prevention. We propose use of this term for patients who have arterial plaque but have not yet experienced a CV event. Given the presence of plaque, especially in patients who also have chronic inflammation, the risk for a heart attack or stroke outweighs the potential harms of low-dose ASA.
• Tertiary prevention. We propose this term to describe what the standard of care currently calls “secondary prevention,” i.e. patients who have already experienced one or more CV events. The benefits of aspirin for this group are undisputed.
We also recommend that patients who are being considered for low-dose ASA for prevention of CVD or CV events be screened for aspirin resistance. In a meta-analysis of 1,813 patients with CVD from twelve prospective studies, the average prevalence of aspirin resistance was 27%. Aspirin-resistant patients were also found to have nearly quadruple the rate of CV events, compared to aspirin-responsive patients. These findings highlight the importance of determining each patient’s ASA status before prescribing a therapy that may fail to protect a large proportion of patients.
Moreover, this research — and another recent study reporting that aspirin-resistant patients are 14 times more likely to suffer recurrent strokes than ASA-responders — also reveals the value of a personalized approach to prevention in which each patient is treated as a unique individual, not according to the average results of large studies. Also talk to your medical provider about getting a new test called MyPGt to personalize your care so you get the safest, most effective medications at the right dose, based on your unique genetics.
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