For many years, it has been established that a daily amount of low dose aspirin could be a strategy for secondary prevention of cardiovascular disease (CVD). Secondary prevention refers to preventing a heart attack or stroke through some therapy and lifestyle counseling for individuals at high risk which includes those with a previous cardiac event or known cardiovascular diseases. However, it has been a more controversial topic as to its effectiveness in women. Early studies on the topic for primary prevention enrolled few women or none at all, leading to a gap in the understanding of the value of daily low dose aspirin for women. The Women’s Health Study was the first large trial to examine aspirin use in women and demonstrated a significant reduction in ischemic stroke (diminished blood supply preventing brain tissue from getting enough oxygen and nutrients) but showed no benefit for major CVD. This suggested that there were differences in aspirin for primary prevention between men and women. Three more trials have examined the benefits of aspirin for primary prevention in men and women and guidelines have been updated.
Updated 2022 guidelines: The US Preventive Services Task Force (USPSTF) released new recommendations in 2022 on the use of low dose aspirin for primary prevention of CVD.
The key points are for primary prevention:
- Individualize the decision and initiate low dose aspirin only for adults aged 40 to 59 with a 10 year CV risk of 10% or more and who do not have an increased risk of bleeding. You can do your risk calculation by a google search of Framingham Risk Calculator. You will need to know your total cholesterol and HDL cholesterol, and systolic blood pressure.
- Recommends AGAINST initiating low dose aspirin for all adults aged 60 years or older.
The 2022 USPSTF recommendations were updated in response to the results of three clinical trials in 2018.
- The Aspirin to Reduce Risk of Initial Vascular Events- ARRIVE- trial, which found no significant differences in CV outcomes in participants with moderate CVD risk when taking 100 mg daily of aspirin vs. placebo. This study included men 55 years and older with two or more CVD risk factors and women aged 60 years and older with three or more CVD risk factors. One of the concerns for women is that they were twice as likely to have gastrointestinal bleeding than those taking placebo.
- In the Study of Cardiovascular Events in Diabetes (ASCEND) trial, 40% of the study included women aged 40 and older and either 100 mg daily of aspirin or placebo. Over an average follow-up period of 7.4 years, the use of aspirin reduced the incidence of serious vascular
Events (nonfatal heart attacks or stroke, TIA= transient ischemic attack, or death from any vascular cause) by only 1% and there was an increase of major bleeding of 1%.
- The Aspirin in Reducing Events in the Elderly (ASPREE) trail found no significant difference in the disability or death or major adverse cardiovascular events (fatal coronary heart disease, heart attack, stroke or heart failure hospitalization), in those who were 70 year or older, 56% of whom were women, who took 100 mg of aspirin or placebo daily. In this study too, there was an increased risk of significant bleeding with aspirin and higher rates of mortality due to all causes in those taking aspirin. This was mostly cancer related deaths.
It’s possible that these now neutral non effective results of aspirin studies might be due to widespread use of statins. The statin use in these three trials summarized above ranged from 34% to 74%. Statins don’t only lower total cholesterol and LDL cholesterol, but also reduce blood platelet aggregation (stickiness) and lead to downregulation of the blood coagulation cascade.
These new recommendations are an important guide for women and their practitioners. We need to consider age, the 10 year CVD risk and the bleeding risk when deciding to start low dose aspirin for primary prevention of CVD. For secondary prevention, it can still be considered, although we still need to assess risk for bleeding before we consider it.
As a Naturopathic Physician, I have core strategies for primary and secondary prevention of CVD. It all starts with a good medical history, physical exam and select testing. Interventions include nutrition, exercise, low alcohol, no nicotine, stress management, weight management, normal blood pressure and keeping an eye on prevention of type two diabetes. The Mediterranean Diet is considered the strongest guide to reduce the risk of CVD and type two diabetes. Weight management is complex and requires different approaches for different folks. The role of menopausal hormone therapy needs to be individualized for benefits vs. risks. Select nutraceuticals and botanicals can be used to lower cholesterol, triglycerides, blood pressure, blood sugar and mental health. Not all cases require over the counter or prescription pharmaceuticals, and not all women can be offered good medical care without them.
Resources:
US Preventive Services Task Force; JAMA 2022; 327:1577
Mora S, Shufelt C, Manson J. Whom to treat for primary prevention of atherosclerotic cardiovascular disease: the aspirin dilemma. JAMA Intern Med 2022;182;587
Framingham Risk Score for Coronary Artery Disease www.mdcalc.com
