10 Things You Should Know About Heart Disease in Women
Women's unique heart risk are spurring changes in prevention and diagnosis
Heart disease isn't a gender-neutral condition. Although many of the risk factors are the same in women and men—including high cholesterol, inactivity, obesity, high blood pressure, and smoking—heart disease can develop differently in women than men, cause different symptoms, and haave a different impact on long-term health. There's a lot more to learn about how women's hearts differ from men's, how they age, and how they respond to diet, exercise, stress, and other influences. Research is ongoing — so stay tuned. In the meantime, here are 10 things you should know about women's heart risks and how best to manage them.
Cholesterol. A low level of "good" HDL cholesterol—below 50 milligrams per deciliter (mg/dL)—is a bigger problem for women than elevated "bad" LDL cholesterol. In fact, the total cholesterol level is less important than the ratio of total cholesterol to HDL cholesterol. For women, the optimal ratio is less than 3.2. High triglycerides (over 150 mg/dL) also pose a bigger heart risk for women than men.
Inflammation. Evidence that inflammation plays a role in the formation of artery blockages has put a spotlight on C-reactive protein (CRP), a substance the body produces in response to inflammation. Now there's a test for blood vessel inflammation called high-sensitivity CRP, or hsCRP. The Women's Health Study found that women with high hsCRP results were about twice as likely as those with high LDL cholesterol to die from a heart attack or stroke. As a result of such findings, the hsCRP test is now often used to estimate the likelihood of a heart attack.
Blood pressure. Up to age 55 or so, women are less likely to have high blood pressure than men. After that, their blood pressure typically rises more sharply than men's, and by age 70, about 80% of women have hypertension. An optimal level is less than 120/80 millimeters of mercury (mm Hg).
Exercise. The more physically active you are, the lower your risk of heart disease. Exercise can raise HDL levels, lower triglycerides, and ease inflammation, changes that are especially important for women. It also helps relieve mental stress—a risk factor for high blood pressure and thus heart problems.
Symptoms. Women are more likely than men to report less dramatic symptoms of heart disease and heart attack, including general discomfort, exhaustion, or shortness of breath under stress or during daily routines. Women are also more likely to complain of fatigue, nausea, back pain, dizziness, and palpitations.
Depression. The links between the mind and heart health are hard to quantify, but most health experts agree that psychological factors can contribute to cardiac risk. One of the most significant for women is depression, associated with an increased risk of fatal heart disease, including sudden cardiac death, even after correcting for other risk factors (including high blood pressure, high cholesterol, smoking, obesity, and inadequate exercise). Direct biological mechanisms may also be involved, including increases in inflammatory responses and blood clotting. If you're having a difficult time emotionally, your heart health is among the many reasons to consider seeing a mental health professional.
Sleep. In addition to sleep apnea, poor sleep is associated with high blood pressure, atherosclerosis, heart failure, heart attack, stroke, diabetes, and obesity. In one study, middle-aged women who got no more than five hours of sleep per night over a 10-year period had a 30% greater risk for heart disease than women who averaged eight hours. Inadequate sleep has also been linked to coronary calcium, a component of atherosclerotic plaque.
Risk assessment. For many years, experts have relied on a risk-assessment tool based on data from the Framingham Heart Study. It estimates the risk of having a heart attack in the next 10 years by taking into account age, gender, smoking, cholesterol levels, and blood pressure. A new measure known as the Reynolds risk score adds hsCRP testing and family history to the risk calculation and has improved predictive ability, especially for heart attacks in women.
Medications. Statins have become the treatment of choice for improving cholesterol levels. These drugs lower LDL, slightly boost HDL, and slightly lower triglycerides, by amounts that vary depending on the statin. Statins are an option if your cholesterol remains high despite lifestyle changes. But they're not for everyone. They may cause troubling side effects — especially muscle aches and, rarely, liver problems. And although they've been shown to reduce the risk of cardiovascular events (including fatal heart attacks) in women who already have heart disease, it's not clear whether women with high cholesterol but no symptoms of heart disease can also benefit. Talk to your clinician. If you have high triglycerides and high LDL, a class of drugs known as fibric acid derivatives may help. If you have low HDL cholesterol, one option is niacin, which both increases HDL and decreases LDL and triglycerides. Niacin usually must be given at a relatively high dose and monitored by a clinician.
SIDEBAR: What about Aspirin? Aspirin is a question mark for women. A daily aspirin has been shown to reduce the risk of a first heart attack in men, but the Women's Health Study found more equivocal results for women. Daily aspirin helped prevent ischemic stroke (the most common type), and it was somewhat effective in preventing heart attacks among women ages 65 and over. But for women under age 65, regular aspirin use was no better at preventing heart attacks than taking a placebo. Clearly, aspirin isn't a miracle worker, and it's not entirely benign either. Gastrointestinal bleeding and hemorrhagic stroke are risks of regular aspirin use. Talk to your clinician about the risks and benefits of aspirin for you. And keep in mind that a healthy lifestyle can be far more effective than aspirin in preventing heart attacks and strokes.
Improved Diagnosis. The standard approach for assessing cardiac symptoms starts with electrocardiography (ECG) — at rest and on a treadmill (stress testing) — and may progress to coronary angiography, an x-ray that outlines any blockages in the coronary arteries. But ECG can miss heart disease in women, and angiograms can fall short, as noted earlier. What to do. Nuclear stress testing and stress echocardiography are more reliable than ECG and are available in many centers. Also, some women may need two other tests: intravascular ultrasound, which captures cross-sectional images of the artery walls, and coronary flow reserve studies, which measure blood flow in response to increased demand, often revealing whether the microscopic vessels in the heart wall are supplying it with enough blood. Both tests can be performed during angiography.
Last Word — If you have worrisome symptoms, speak up. And make sure you have a clinician who listens and takes your concerns seriously. You may want to consider finding one at a center that specializes in women's health or at a heart center.
Harvard Women's Health Watch is available from Harvard Health Publications www.health.harvard.edu, the publishing division of Harvard Medical School, for $28 per year. Subscribe at www.health.harvard.edu/women