July 30, 2013
Coronary Artery Disease Often Neglected In Women Despite High Risks
Rebekah Eliason for redOrbit.com - Your Universe Online
Although coronary artery disease (CAD) causes as many deaths in women as it does men, preventative recommendations, such as lifestyle advice, aspirin and lipid-lowering therapy are still suggested less for women than men who have the same risk levels.
A new study, by Dr Kavita Sharma, MD, of cardiovascular medicine and Dr Martha Gulati, MD, Director of Preventive Cardiology and Women's Cardiovascular Health at Ohio State University, which outlines the challenges for women with CAD, is published in the journal Global Heart.
Each year, approximately 8.6 million deaths, a third of all deaths in women worldwide, are due to cardiovascular disease (CVD), including CAD. An estimated 17.3 million people worldwide died in 2008 from CVD, which accounts for 30 percent of all global deaths. These deaths due to heart disease occurred almost equally between men and women. The leading cause of death globally is CVD with an estimated rise to 23.3 million deaths by 2030.
Authors Sharma and Gulati noted, "CAD is a leading cause of death of women and men worldwide. Yet CAD's impact on women traditionally has been underappreciated due to higher rates at younger ages in men. Microvascular coronary disease disproportionately affects women. Women have unique risk factors for CAD, including those related to pregnancy and autoimmune disease. Trial data indicate that CAD should be managed differently in women."
In the United States, and most developed countries, CAD is the leading cause of death for both men and women. "More women than men die of CAD, and more women have died from CAD than of cancer (including breast cancer), chronic lower respiratory disease, Alzheimer's disease, and accidents combined," said the authors.
Encouragingly, the rate of death due to CAD has lowered 30 percent in the US from the years 1998 to 2008. Other developed countries have recorded a similar decline in death from CAD. Although there is an overall decrease in CAD deaths, due to several risk factors, rates of incident are increasing in women aged 55 and under.
Due to large amounts of research in recent years, it has been discovered that heart disease often develops differently in women than men. For example, obesity increases the risk of CAD by 64 percent in women but only 46 percent in men. Also, women younger than 50 who experience a heart attack related to CAD are twice as likely to die as men who experience a heart attack under similar conditions.
In those 66 years of age and older, 42 percent of women die within one year of a heart attack while only 24 percent of men will die within a year. Based on results from several developed countries, women are at a 20 percent greater risk than men to experience chest pain or discomfort from poor blood flow through vessels in the heart, known as angina.
According to CT scans and other imaging techniques, women have narrower coronary arteries than men, which lead to greater risk for microvascular disease. The disorder known as microvascular coronary disease affects the very tiny blood arteries in the heart and leaves them diseased or damaged. Even though a major blockage may not appear, women can experience symptoms from small blocks among the tiny blood vessels. Of symptomatic women who do not have obstructive CAD, half experience a restriction of blood to tissue known as ischemia and are repeatedly admitted to the hospital and undergo coronary angiography.
In addition, women are more likely to experience coronary plaque erosion, which causes clots to form; men are more likely to experience a classic heart attack caused by obstructive CAD.
Important risk predictors in women include age, family history of CAD, hypertension, diabetes, dyslipidemia, smoking, and physical inactivity. Statistically CAD is increasing linearly among men but exponentially among women over 60 years of age. Risk factors such as diabetes and having a first degree relative with CAD will increase a woman's chance of getting the disease more than it would for men.
Another critical risk factor for CAD is lack of physical activity. A study performed by the St. James Women Take Heart Project found that women who could not complete a basic physical fitness test were three times more likely to develop CAD than fit women. The World Heart Federation is putting a huge emphasis on heart disease in women and campaigning for increased physical fitness.
An additional risk factor for women concerning heart disease is their likelihood to suffer from an autoimmune disease. Not only do autoimmune disorders increase the risk factor for CAD, they also increases risk for other diseases such as polycystic ovary syndrome, pre-eclampsia, gestational diabetes and breast cancer, which are all conditions that can increase risk of CAD in women.
The authors explained, "As was recently reported, although advances in breast cancer therapies are improving survival in early breast cancer, the gains are being attenuated by increasing CAD risk. Whether the increased CAD risk is due to the breast cancer therapies or to the disease itself - which is associated with some of the same risk factors for CAD - remains unknown."
Awareness of CAD in women is increasing as evident by the fact that in 1997 only 30 percent of Americans knew that CAD was the leading cause of death in women, whereas a 2009 survey reported this number rose to 54 percent. Despite general knowledge increasing, in 2004 a survey found less than one in five physicians were aware that more women die of CAD than men. It was also concerning to find that women were 55 percent less likely than men to utilize cardiac rehabilitation.
The authors concluded, "Women are affected by CAD in large numbers and to a large degree. CAD is the leading cause of mortality in women. The manifestation of CAD has unique characteristics in women. Increasing data demonstrate that some treatment strategies have sex-specific effectiveness. Further research regarding the pathophysiology of CAD in women, diagnosis, and treatment strategies specific to women is required. CAD is not a 'man's only' disease, and we eagerly await future studies that examine its unique presence in women."