What is Congestive Heart Failure?

1. What is Congestive Heart Failure? Robert Grimshaw MD FACP A Lifetime of Quality Care That’s Convenient & Complete

2. What is Congestive Heart Failure? CHF, as we will refer to it, happens when the demand on the heart exceeds its blood supply. There are many reasons: damage to the heart’s valves, to the muscle directly, or to the arteries. The most common cause in the U.S. is diseased coronary arteries and previous heart attacks. The most common symptom is fatigue; the next is breathlessness.  CHF is deadly: for men, ½ are dead in 5 years; for women, 1/3. In this update, we’ll review the most common treatments and what’s coming up.

3. Common Treatments Tried and True: Diuretics "Water pills" are used to reduce the amount of blood that the heart has to pump, hence less "back up" into the lungs. The most common are furosemide (Lasix), torsemide (Demadex), and hydrochlorothiazide (Hydrodiuril, others). Digitalis: This derivative, digoxin (Lanoxin), of the purple foxglove plant is used to help keep rapid rhythms under control and to boost the heart’s output slightly. Recent studies have shown it can help keep patients out of the hospital, but does not extend life. ACE Inhibitors: Angiotensin-Converting-Enzyme inhibitors such as enalapril (Vasotec), lisinopril (Prinivil, Zestril), ramipril (Altace), and others help extend life (mortality drops 25%) and reduce symptoms. The reasons are several, involving blood pressure control, improved kidney function, and changes in the hormones affecting the heart.

4. Common Treatments (continued) ARBs:Angiotensin-Receptor-Blockers are close cousins of ACE inhibitors. Early data indicate that these drugs such as losartan (Cozaar), valsartan (Diovan) and others can substitute for or add to the effect of ACE inhibitors. Beta-Blockers: Metoprolol (Lopressor, Toprol) and carvedilol (Coreg) have been shown to dramatically improve life expectancy by again changing hormone effects. Aldactone or spironolactone has been shown in 1 study to cut death by 30% and hospitalization by 35% in 2 years.

5. Treatments Coming Up Omapatrilat (Vanlev from Bristol-Meyers Squibb) combines 2 effects: it blocks ACE and it inhibits neutral endopeptidase (NEP), to keep atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels up. ANP & BNP work to get rid of sodium (and thus excess fluid), lower blood pressure, and open blood vessels. Studies are underway to see about this drug with and without ACE inhibitors, and are promising. Endothelin Receptor Antagonist: endothelin is the most potent substance known for causing arteries to "clamp down" or constrict. It is elevated in CHF. Bosentan (Tracleer) is an endothelin antagonist that has been released for high pressure on the lung or right side of the heart (Pulmonary hypertension). Other endothelin antagonists are in early human study. So far, it looks like the class will be most helpful in right heart failure.

6. Treatments Coming Up (continued) Pacing: One of the problems in CHF is that the contraction of heart muscle is disordered. There is less time for the main pump (left ventricle) to fill, and there’s a back-leak ("regurgitation") through the mitral valve into the left atrium. Trials are underway to use pacemakers to "resynchronize" contraction. ADH Receptor Blocker: anti-diuretic hormone is elevated in CHF. Blockers are in early trial o combat salt and water retention. Enoximone is an inhibitor of phosphodiesterase, and increases the calcium available in heart muscle cells to increase pumping. It is the latest in a series of these to be tried in CHF. Pumps: Mechanical left and right ventricular assist devices (LVAD/RVAD) have improved and permanent implants are being investigated; the ultimate replacement pump is a heart transplant, but only 2500 per year are done in the U.S.