Diuretics for heart failure in adults

Chronic heart failure (CHF) (also called congestive heart failure, cardiac failure and heart failure) is a disorder in which the heart loses its ability to pump blood efficiently throughout the body. The oxygen and nutrients in the blood provide the body with the energy it needs to operate efficiently. Chronic heart failure causes breathlessness and fatigue because the heart cannot function as it should. Heart failure may affect the left, right, or both sides of the heart. If the left half of the heart fails (left ventricular failure), fluid will build up in the lungs due to congestion of the veins of the lungs. If the right half of the heart fails (right ventricular failure), general body vein pressure will increase and fluid will accumulate in the body, especially the tissues of the legs and abdominal organs (of these, the liver is the organ most likely to be affected). Often left heart failure leads to right heart failure causing biventricular failure (both sides). Fluid may build up in the lungs and legs. Coronary artery disease, a heart attack, or high blood pressure are some of the causes of heart failure. Drug treatments include digitalis, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers and diuretics. Diuretics are important as they relieve symptoms quickly and control fluid retention. Possible side effects with diuretics include heart irregularities (arrhythmias), low blood pressure and disturbed kidney function. Some of the diuretics used are furosemide, bumetanide and chlorothiazide. The available data from several small controlled trials show that in patients with CHF, conventional diuretics appear to reduce the risk of death and worsening heart failure when compared to an inactive sugar pill (placebo). About 80 deaths may be avoided for every 1000 people treated. Diuretics also increase the ability to exercise, by about 28% to 33% more than with other active drugs. These conclusions were based on 14 controlled trials (525 people), of which three trials noted deaths in 202 people randomised to receive either diuretic or placebo, and two trials, a total of 169 people, looked at hospitalisation for worsening heart failure. Of the seven trials comparing diuretic treatment with another drug, the effects on exercise were studied in four trials where 91 people were randomised to receive either a diuretic or an ACE inhibitor or digoxin. Most of the trials had small numbers and lasted from 4 to 24 weeks, a short time for a chronic disease. The age of the participants was 59 years, which is relatively young, and the use of diuretic drug was not standardised across the studies. More research would be needed to further confirm the long term benefits of diuretic treatment for CHF patients because these studies were small.