Angina, a common form of heart disease, is more dangerous for women than was previously thought, according to a new study published in the Journal of the American Medical Association (JAMA).
The collaborative study, led by UCL (University College London) and funded by the British Heart Foundation, found that angina in women is as common as it is in men, in contrast to heart attacks (myocardial infarction) which have a higher rate in men. The findings suggest that the medical profession should pay more attention to thoroughly investigating and diagnosing women suspected of having angina.
UCL Professor Harry Hemingway and colleagues studied over 100,000 patients aged 45-89 years with angina using electronic health records. They found that each year, two women out of every 100 in the general population developed angina, as the first sign of heart disease. This makes angina much more common than heart attacks (the risks of which are usually measured per 1,000 population).
The study also found that for women, the diagnosis of angina is less frequently confirmed with tests, such as angiograms or treadmill exercise electrocardiograms. In the patients in the study, drug treatment aimed at relieving angina (nitrates) was prescribed solely on the basis of symptom history.
In the study, angina in women was also associated with increased death rates, where women diagnosed without the confirmatory test had significantly higher death rates from heart disease. Such women have often been dismissed as having a ‘soft’ subjective complaint, without real pathological changes in the heart. The study suggests that this attitude is incorrect.
Among women with angina and diabetes, the annual risk of a heart attack was particularly high and similar to the risk in men (about one in 10).
Professor Hemingway, from the UCL Department of Epidemiology and Public Health, says: “For women, angina is a more significant public health problem than many doctors, or indeed the general public, realise. Women develop angina at a similarly high rate as men. And the angina which women experience is not benign in terms of death rates. We need to understand why women are relatively protected from heart attack but not from angina, and ensure fair access to investigation and treatment services.
“Angina has been a Cinderella in heart disease research because of the difficulties in establishing which patients have angina – many people with symptoms are not tested – and because most patients are not hospitalised. The opposite is true for heart attacks, where nearly all patients are tested to confirm the diagnosis and are admitted as an emergency into hospital.”
Angina is a symptom of chest pain or discomfort which is brought on by exercise (or cold or emotional stress) and relieved by rest. These symptoms are due to the supply of oxygen to the heart muscle (myocardium) being insufficient to meet demand (so called myocardial ischaemia). Narrowing and hardening of the blood vessels which supply oxygen to the heart muscle causes angina. Atherosclerosis is the cause of the narrowing and hardening of the coronary (heart) arteries.
Angina is more likely to occur in people who have one or more of the following risk factors: older age, smoking, high blood pressure, high cholesterol, diabetes, obesity, family history.
Angina can be prevented by lifestyle changes (stopping smoking, increasing exercise) and by lowering blood pressure and cholesterol. The symptoms of angina can be relieved with medication (such as nitrates or beta-blockers) and by undergoing a coronary revascularisation procedure. The risk of having a heart attack after having experienced angina can be reduced by taking ‘secondary prevention’ medications such as aspirin and lipid lowering drugs. There is no cure for the underlying disease process of atherosclerosis.