Congestive Heart Failure
DescriptionAn in-depth report on the causes, diagnosis, treatment, and prevention of CHF.
Alternative NamesCardiomyopathy; Heart Failure
Nearly five million Americans currently suffer from heart failure, and about 550,000 new cases of heart failure are now diagnosed each year. In 1970 there were only 250,000 new cases, so the annual numbers have risen dramatically. Nevertheless, such numbers represent an increasingly older population. According to a 2002 study, the actual risks for men are stable and for women they may even be declining. In addition, the risk for death after heart failure is diagnosed has declined by 12% every decade. The study was limited, however. Subjects were nearly all Caucasian and they had access to good preventive health care. In general, because diabetes and obesity are at epidemic levels, experts have expected heart failure rates to increase.
Heart failure is the most common reason for hospitalization in the elderly, and as the population ages, the incidence of congestive heart failure is rising dramatically. According to one report, it occurs at a rate of about 10 per 1,000 people after age 65. The positive implication of that report, however, is that people are living longer with heart failure.
Men are at higher risk for heart failure than women, although the difference narrows with age. Women also have a better survival rate than men do when heart failure is caused by valvular heart disease, high blood pressure, or alcohol abuse. (Some studies indicate that this is because men may be more susceptible to the process of heart muscle-cell remodeling, a damaging effect of hypertension.)
The survival rates of women and men are more similar, however, when heart failure evolves from coronary artery disease or heart attack. In fact, women are much more likely to develop heart failure after a heart attack than men. In such cases, some evidence suggests that the reasons for this may include less aggressive approach to treatment for the initial heart conditions.
African-Americans are at higher risk for heart failure than are Caucasians, and studies have reported that they tend to do much worse. In a 2003 study, however, in which Caucasians and African-Americans had comparable treatment, African-Americans actually had lower one-year mortality rates (with slightly higher rates of rehospitalizations). Still, more studies are needed to determine if there are actual biologic differences in specific patients. Some evidence, for example, suggests that African-Americans are more often likely than Caucasians to develop diastolic heart failure (a failure of the heart muscle to relax normally), which is often a precursor to systolic heart failure (impaired ability to pump blood). Caucasians tend to develop systolic heart failure first. In one study comparing Caucasian and African-Americans who only had diastolic heart failure, African-Americans had a 30% higher mortality rate.
Family History and Genetics
A family history of early congestive heart failure caused by cardiomyopathies (diseases that damage the heart muscle) may predispose people to the disease. Researchers are also looking for changes in specific genes that might regulate systems involved in heart failure and so increase susceptibility in certain populations.
Chronic Alcohol Abuse
Chronic alcohol abuse can damage the heart muscles, can cause hypertension, and may prove to be one cause of idiopathic dilated cardiomyopathy. Moderate alcohol consumption, on the other hand (generally defined as two drinks a day for men and one for women), may protect against heart failure. Teetotalers, though, are not advised to begin drinking.
Medical Conditions that Increase the Risk for Heart Failure
Medications and Other Factors Associated with Heart Failure
Thiamin (a vitamin B) deficiency can lead to reversible cardiomyopathy. Long-term use of anabolic steroids (male hormones used to build muscle mass) increases the risk for heart failure. The drug itraconazole (Sporanox), taken orally for skin, nail, or other fungal infections, has been linked to heart failure in a small number of cases.