Two high blood pressure medicines effective in treating stable ischemic heart disease

Two medications commonly used to treat high blood pressure appear to be effective in treating a common type of heart disease known as stable ischemic heart disease, according to a new comparative effectiveness review funded by HHS' Agency for Healthcare Research and Quality. A version of the analysis was posted in the October 20 online version of the Annals of Internal Medicine.

Treatment featuring the two medications -- inhibitors of angiotensin-converting enzyme, or ACE inhibitors, and angiotensin receptor blockers, or ARBs -- can lead to a reduction in death, risk of heart attack, risk of stroke and fewer hospitalizations for heart failure for patients suffering from stable ischemic heart disease, researchers found. However, the drugs have risks of their own. Risks associated with ACE inhibitors include a persistent cough, sudden fainting, too much potassium in the blood, and dangerously low blood pressure (hypotension). Risks associated with ARBs include too much potassium in the blood and low blood pressure.

"Stable ischemic heart disease is a major cause of death in the United States, so these findings are very encouraging," said AHRQ Director Carolyn M. Clancy, M.D. "This comparative effectiveness report will be a useful tool for patients to help them work with their clinicians to make choices on treatment."

Stable ischemic heart disease occurs when the flow of oxygen-rich blood to the heart is reduced because of narrowed or blocked arteries. Symptoms of stable ischemic heart disease include decreased tolerance of exercise and severe chest pain on exertion (known as angina), which afflicts about 9 million U.S. adults. Long-term risks of stable ischemic heart disease include heart failure and heart attack. Overall, heart disease is among the nation's most common and deadly illnesses, afflicting nearly 80 million Americans and killing nearly 2,400 every day.

Standard treatment of stable ischemic heart disease consists of a modification of diet, exercise and medications including aspirin, anti-cholesterol drugs, nitroglycerin and beta blockers. These can keep the disease from worsening. However, while standard treatment usually alleviates chest pain, it is not universally successful in reducing risk of heart failure or heart attack.

For patients with advanced stable ischemic heart disease, treatment can include heart surgery (coronary artery bypass graft, in which surgeons use a blood vessel harvested from the chest, leg or arm to reroute blood flow around narrowed heart arteries) or angioplasty (a procedure in which a catheter is used to inflate a balloon inside the plaque-narrowed artery and a mesh tube called a stent is usually inserted to keep the artery open).

ACE inhibitors and ARBs, which are commonly prescribed to combat high blood pressure, also are used for treatment of a heart attack and chronic heart failure. Captopril (sold as Capoten), the first ACE inhibitor to be taken orally, has been commonly available in the United States since the early 1980s. ARBs, first approved for use in the United States in the mid-1990s, often are prescribed when a patient has adverse effects to ACE inhibitors, but ACE inhibitors are used more commonly.

The AHRQ report found that patients with stable ischemic heart disease who take an ACE inhibitor in addition to standard treatment can reduce the likelihood of several negative outcomes, including death from heart attack or heart failure, non-fatal heart attacks, hospitalization for heart failure, and revascularization (surgeries that reroute blood to the heart). Patients who take an ARB in addition to standard medications can reduce their risk of death from a heart-related cause, heart attack or stroke.

While some patients and clinicians pursue a course of treatment using both ACE inhibitors and ARBs, the report found that combined treatment does not show any benefit over an ACE inhibitor alone and that risks include fainting, diarrhea, low blood pressure and kidney problems.

The report found that existing studies provide few data on the medications' benefits or harms in specific populations such as people of different genders, ethnicity, diabetic status or those who have or don't have high blood pressure.