The Cleveland Clinic Heart Advisor

Volume 12
Number 7
July 2009

Many of the charts & tables found on this site are PDFs.

July 2009

Live a Fuller Life with Heart Failure
It’s a condition that can sound worse than it really is, but heart failure (HF) is serious and special precautions should be taken by HF patients who don’t want their cardiovascular health to rob them of their quality of life. Contrary to a popular misunderstanding, heart failure does not mean that the heart has "failed" and is no longer working. Instead HF simply means that the heart is no longer pumping efficiently and fails to sufficiently supply all the blood needed to meet the body’s needs. It’s estimated that about 5 million Americans have HF, and about 550,000 new cases are diagnosed annually. "Heart failure is a disease you can live with for a long time," says Cleveland Clinic cardiologist Curtis M. Rimmerman, MD. "With advances in medication and technology, there are more treatment options available now than ever before." For example, left ventricular assist devices (LVADs), which are basically mechanical heart pumps, used to serve only as bridges for patients waiting for heart transplants. Today, LVADs also are being used as "destination therapy," improving quality of life among patients with serious HF. And in March, the American Heart Association (AHA) and the American College of Cardiology updated their HF treatment guidelines and strengthened their recommendations for the use of the vasodilators hydralazine (Apresoline) and isosorbide dinitrate (Dilatrate), which improve blood flow by relaxing the smooth-muscle walls of blood vessels.

Control Blood Glucose Levels to Minimize Heart Risk
It’s well documented that diabetes can seriously complicate a heart condition, but research continues to show that elevated glucose levels that aren’t yet considered diabetes can boost our risk of cardiovascular problems, even if we don’t yet have heart disease. An estimated 37 million Americans age 65 and older have diabetes, about a quarter of that population. But an additional 20 to 30 percent of seniors—about 7 to 11 million older adults—are not considered to have diabetes, but do have the form of "pre-diabetes" called impaired glucose tolerance. Unfortunately, it’s a condition that can be overlooked by physicians because pre-diabetes is seldom accompanied by obvious symptoms. Older adults who have impaired glucose tolerance, but are not yet considered diabetic, have an elevated heart disease risk and may benefit from preventive therapies, according to a study published in the March issue of the Journal of Clinical Endocrinology & Metabolism. Impaired glucose tolerance or impaired fasting glucose refer to a mean blood glucose level that is in the 100-125 mg/dl range. Normal is considered 70-100 mg/dl and diabetes is considered 126 mg/dl or higher, as measured on at least two occasions.

Protect Yourself from Peripheral Arterial Disease
Peripheral arterial disease (PAD) affects between eight and 12 million Americans and can lead to severe obstruction of blood flow in the lower extremities if not treated. But a study published in the May 1 issue of Catheterization and Cardiovascular Interventions: Journal of the Society for Cardiovascular Angiography and Interventions showed that PAD is often overlooked in patients with existing heart disease, often because it can exist for some time before symptoms, such as leg pain, develop. "‘PAD’ is the term used to refer to vascular disease of the extremities, generally the legs, but also the arms," says Heather Gornik, MD, a staff physician in the Robert and Suzanne Tomsich Department of Cardiovascular Medicine in the Sections of Clinical Cardiology and Vascular Medicine and medical director of the Non-Invasive Vascular Laboratory at Cleveland Clinic. "The most common cause of PAD is atherosclerosis, or plaque formation in the arteries."

Know the Risks and Benefits of Stents and Bypass Grafts
Several criteria must be considered in deciding whether your blocked coronary arteries are treated with bypass surgery or with stents. The size and location of the blockages are perhaps the greatest determining factors, but a recent study suggests that age and diabetes should be part of the equation, too. A study of more than 8,000 heart patients, published in the March 19 issue of The Lancet, found that those patients with coronary artery disease (CAD) who were 65 and older or who were diabetic fared better after bypass surgery than stenting. Cleveland Clinic cardiovascular surgeon Marc Gillinov, MD, suggests, however, that age doesn’t significantly raise the risk for either approach. "Both procedures are very safe," Dr. Gillinov says. "Most studies show that patients with diabetes have superior long-term outcomes with bypass surgery if they have three-vessel disease." He adds, however, that three-vessel disease or left main coronary artery disease is typically treated with bypass surgery anyway and that single- or double-vessel disease may be best treated with stents, again depending on all factors. Multi-vessel disease refers to blockages in more than one of the coronary arteries—the blood vessels that supply the heart muscle with oxygen-rich blood.

You and Your Heart Need a Good Night’s Sleep
When you think about heart health, sleep may not be the first thing that comes to mind, but evidence that ties poor sleep to an increased risk of heart-related problems is growing. "When you’re not getting good sleep, there’s a whole host of biological and neurochemical balances that can be put out of balance," explains Michael Faulx, MD, a cardiologist with the Sydell and Arnold Miller Family Heart & Vascular Institute. "Your body secretes hormones that can increase your blood pressure and heart rate and raise the level of inflammation. All of these can have a negative impact on heart health."

What You Need to Know About ARBs
Angiotensin receptor blockers (ARBs) are used to treat hypertension (high blood pressure) and heart failure, and also may be used to help prevent the recurrence of atrial fibrillation (a type of heart arrhythmia), and kidney failure in people with hypertension or diabetes. There is some evidence that they also may be associated with a decrease in the occurrence and progression of dementia and a lower risk of nonmelanoma skin cancer. Commonly prescribed ARBs include losartan (Cozaar), telmisartan (Micardis) and valsartan (Diovan) and they also are available in combination form with other antihypertensives and with the diuretic hydrochlorothiazide. ARBs work by targeting one of the body’s natural chemical messengers, angiotensin II. Angiotensin II causes the muscles surrounding the blood vessels to contract, narrowing the vessels in the process. This increases pressure within the blood vessels, resulting in hypertension. ARBs prevent angiotensin II from binding to angiotensin II receptors on blood vessels and other body tissues, thereby limiting its actions and allowing the blood vessels to relax and dilate.

Understand Women’s Risks with Revascularization Procedures
By now you should know the modifiable risk factors for heart disease: smoking, obesity, inactivity, high blood pressure, high cholesterol, metabolic syndrome and diabetes. These risk factors not only increase the risk of heart attack, but studies suggest they may also increase the risk a woman will die from coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI)—procedures designed to improve blood flow to the heart muscle. A retrospective study of 976 patients—one-third of them female—who underwent CABG found that the women were more likely than the men to have diabetes or hypertension, and be overweight, older, or African-American. These risk factors, in addition to smoking and recent heart attack, increased the risk of in-hospital complications or death from the procedure. In this study, published in the April issue of Interactive Cardiovascular and Thoracic Surgery, the mortality rate for women undergoing CABG was 5.5 percent, as compared with 1.86 percent for men.

Recommendations for Dietary Omega-6 Fatty Acids Released
In January 2009, the American Heart Association issued a scientific advisory recommending that a minimum 5 to 10 percent of calories be obtained from omega-6 fatty acids. This fatty acid is found in nuts, seeds and vegetables, nut- and seed-based oils such as peanut oil, soybean oil, safflower oil and canola oil. The advice was based on a meta-analysis of randomized, controlled studies showing that people who ate the most omega-6 fatty acids had the least amount of heart disease, and that people with heart disease had lower levels of omega-6 in their blood than healthy people. Replacing saturated fats from meat, full-fat dairy products, coconut oil and palm oil with omega-6 sources lowered the risk of heart attack by 24 percent.

High Resting Heart Rate Could Help Predict Future Heart Attack
A study published in the February 4 online issue of the British Medical Journal has established that middle-aged women with a high resting heart rate are at increased risk of heart attack. Although the increase in risk was not equal to that conferred by high LDL cholesterol, it was significant enough that the authors recommended physicians routinely test resting heart rate in their female patients. The study was based on data from 129,135 postmenopausal women who participated in the Women’s Health Study. They were divided into five groups by resting heart rate and followed for 7.8 years. No unusual risk was found among women in the first four quintiles. However, the group with heart rates of 76 beats per minute or more had a 26 percent increased risk of heart attack.