Refractory congestive heart failure: overview and application of extracorporeal ultrafiltration

Abstract

Congestive heart failure (CHF) from ischemic cardiomyopathy has emerged as an epidemic health problem. The pathogenesis of CHF is characterized by heightened activity of many neuroendocrine factors, including norepinephrine, angiotensin II, and arginine vasopressin, which lead to heightened systemic vascular resistance and further impedance of left ventricular ejection. Once CHF reaches New York Heart Association (NYHA) class III or IV with heightened activity of the many neurohumoral factors, it tends to be refractory to conventional therapy of vasodilators, inotropic agents, and diuretics. Treatment of refractory CHF appears to require a break in the neurohumoral hemodynamic vicious cycle, and ultrafiltration appears able to produce this interruption. Ultrafiltration has been shown to be successful in patients with NYHA class III to VI CHF and urine output less than 1,000 mL/d. It relieves pulmonary edema, reduces ascites and peripheral edema, and enhances the response to subsequent diuretic therapy. In patients with refractory CHF, the ability to provide adequate volume removal, thus improving overall volume status, normalizing filling pressures, and reducing clinical symptoms, offers an improvement in overall quality of life. Early results have shown that ongoing therapy actually may be associated with decreased hospital readmissions or, at the very least, shortened intensive care unit length of stay.