Overestimating heart attack risk means over prescribing medications

Overestimating heart attack risk means over prescribing medications

Most “risk calculators” used by clinicians to gauge a patient’s chances of suffering a heart attack and guide treatment decisions appear to significantly overestimate the likelihood of a heart attack, according to results of a study by investigators at Johns Hopkins and other institutions.


Physicians commonly use standardized risk assessment systems, or algorithms, to decide whether someone needs care with daily aspirin and cholesterol-lowering drugs or just watchful waiting and follow-up exams. These algorithms calculate heart attack probability using a combination of factors, such as gender, age, smoking history, cholesterol levels, blood pressure and diabetes, among others.

The findings, reported in Annals of Internal Medicine, suggest four out of five widely used clinical calculators considerably overrate risk, including the most recent one unveiled in 2013 by the American Heart Association and the American College of Cardiology amid controversy about its predictive accuracy.

The results of the study, the research team said, underscore the perils of overreliance on standardized algorithms and highlight the importance of individualized risk assessment that includes additional variables, such as other medical conditions, family history of early heart disease, level of physical activity, and the presence and amount of calcium buildup in the heart’s vessels.

Recently we reported that more than 10 percent of patients treated with aspirin therapy for primary cardiovascular disease prevention were likely inappropriately prescribed medication, according to a new study in the Journal of the American College of Cardiology that examined practice variations in aspirin therapy.

Aspirin therapy is not shown to reduce adverse cardiovascular events in patients without cardiovascular disease and a low risk of developing disease. However, it is associated with an increased risk of gastrointestinal bleeding and hemorrhagic strokes which often outweighs any potential benefits.

The U.S. Food and Drug Administration recently denied a request to allow the marketing of aspirin for primary prevention, following that decision the FDA also issued a public advisory against the general use of aspirin for primary prevention. As aspirin is available over the counter, it is also possible inappropriate aspirin use is higher if patients are taking it by their own choosing.

Researchers identified patients from 119 practices who were prescribed aspirin between January 2008 and June 2013, excluding patients receiving aspirin as a secondary prevention due to history of cardiovascular disease such as myocardial infarction, prior stroke, and atrial fibrillation.

  • The study found nearly 12 percent of the patients receiving aspirin for primary prevention were receiving it inappropriately.

The frequency of inappropriate aspirin use was higher among women, at nearly 17 percent compared to men at 5 percent. Patients inappropriately receiving aspirin were, on average, 16 years younger than those receiving aspirin appropriately. Inappropriate aspirin use decreased from 14 percent in 2008 to 9 percent in 2013. From the American College of Cardiology.

Women and Low Dose Aspirin

The pros of giving healthy women regular low dose aspirin to stave off serious illness, such as cancer and heart disease, are outweighed by the cons, suggests a large study published online in the British Medical Journal.

  • The pro to con balance begins to shift with increasing age, and limiting this form of primary prevention to women aged 65 and above, was better than not taking aspirin at all, or treating women from the age of 45 onwards, say the researchers.

They base their findings on almost 30,000 healthy women, who were at least 45 years old and taking part in the Women’s Health Study.

Participants were randomly assigned to take either 100 mg of aspirin or a dummy tablet (placebo) every other day, to see whether aspirin curbed their risk of heart disease, stroke, and cancer.

During the trial period, which lasted 10 years, 604 cases of cardiovascular disease, 168 cases of bowel cancer, 1832 cases of other cancers, and 302 major gastrointestinal bleeds requiring admission to hospital were diagnosed.

Over the subsequent seven years, a further 107 cases of bowel cancer and 1388 other cancers were diagnosed.

  • Compared with placebo, regular aspirin was linked to a lower risk of heart disease, stroke, bowel cancer, and in some women, other cancers, but only marginally so.
  • And this slight health gain was trumped by the prevalence of internal gastrointestinal bleeding, which affected two thirds of the women taking the non-steroidal anti-inflammatory drug.


Aspirin’s benefit in diabetic patients

Recently Japanese researchers evaluated aspirin’s benefit in diabetic patients, but first they noted that the benefit of low-dose aspirin for primary prevention of cardiovascular events in diabetes remains controversial. The American Diabetes Association (ADA), the American Heart Association (AHA), and the American College of Cardiology Foundation (ACCF) recommend aspirin for high-risk diabetic patients: older patients with additional cardiovascular risk factors.  So, they looked at 2,539 patients with type 2 diabetes and no history of cardiovascular disease. After analysis they concluded that: Low-dose aspirin is not beneficial in diabetic patients at high risk. 1

Gastro-intestinal complaints

Researchers in Spain recently noted that in patients with low cardiovascular risk the number of gastro-intestinal complaints induced by low-dose aspirin may be greater than the number of cardiovascular risk events prevented. Further, in patients with high cardiovascular risk, low-dose aspirin is recommended, but the number of gastro-intestinal complications induced may still overcome the cardiovascular events saved.”2

Other research suggests that women are not taking enough aspirin for cardiovascular risk. Writing in the Journal of Women’s Health the researchers suggested: “the majority of women for whom aspirin is recommended for primary and secondary prevention of cardiovascular disease were not following national guidelines.”3

The low dose aspirin debate is a complex one. Recent findings revealed that: “The benefit of aspirin for the primary prevention of cardiovascular events is relatively small for individuals with and without diabetes. This benefit could easily be offset by the risk of hemorrhage.”

Low dose aspirin for heart disease – the jury IS in

“aspirin use was significantly associated with an increased risk of major gastrointestinal or cerebral bleeding episodes. Patients with diabetes had a high rate of bleeding…” 4

Researchers writing in the Archives of Internal Medicine have questioned the routine prescribing of low-dose aspirin as a preventive measure for cardiovascular disease in patients without prior cardiovascular disease problems.

This is what they said: “The net benefit of aspirin in prevention of CVD and nonvascular events remains unclear. Despite important reductions in nonfatal MI (Heart Attacks), aspirin prophylaxis in people without prior cardiovascular disease does not lead to reductions in either cardiovascular death or cancer mortality. Because the benefits are further offset by clinically important bleeding events, routine use of aspirin for primary prevention is not warranted and treatment decisions need to be considered on a case-by-case basis.”5

“there is an ongoing debate surrounding use of aspirin for primary (cardiovascular event) prevention. Published evidence does not support the assumption that the balance of benefits and harms of aspirin use is clearly favorable for primary prevention. “6 JAMA

It is very important to talk to your doctor about whether or not aspirin is appropriate for you. Especially if you have heart disease, prior heart surgery or chronic chest pain due to clogged arteries.

At the Magaziner Center for Wellness we have recognized that prevention of cardiovascular disease is reliant on a what is best for the individual patient and that many programs we offer are nutrition based as opposed to medication based.

1. Okada S, Morimoto T, Ogawa H, Sakuma M, Soejima H, Nakayama M, Sugiyama S, Jinnouchi H, Waki M, Doi N, Horii M, Kawata H, Somekawa S, Soeda T, Uemura S, Saito Y; investigators for the Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes (JPAD) trial. Effect of low-dose aspirin on primary prevention of cardiovascular events in Japanese diabetic patients at high risk. Circ J. 2013 Nov 25;77(12):3023-8. Epub 2013 Sep 13.

2. Lanas A, Polo-Tomás M, Casado-Arroyo R. The aspirin cardiovascular/gastrointestinal risk calculator – a tool to aid clinicians in practice. Aliment Pharmacol Ther. 2013 Feb 17. doi: 10.1111/apt.12240. [Epub ahead]

3. Cathleen M. Rivera, Juhee Song, Laurel Copeland, Chris Buirge, Marcia Ory, and Catherine J. McNeal. Journal of Women’s Health. April 2012, 21(4): 379-387. doi:10.1089/jwh.2011.2990.

4. De Berardis G, Lucisano G, D’Ettorre A, et al. Association of aspirin use with major bleeding in patients with and without diabetes. JAMA. 2012;307(21):2286-2294. doi:10.1001/jama.2012.5034.

5. Seshasai SRK, Wijesuriya S, Sivakumaran R, et al. Effect of aspirin on vascular and nonvascular outcomes: meta-analysis of randomized controlled trials. Arch Intern Med 2012; DOI:10.1001/archinternmed.2011.628.

6. Siller-Matula JM. Hemorrhagic Complications Associated With Aspirin: An Underestimated Hazard in Clinical Practice? JAMA. 2012;307(21):2318-2320. doi:10.1001/jama.2012.6152