Relationship between endothelin-1 extraction in the peripheral circulationand systemic vascular resistance in patients with severe congestive heart failure

OBJECTIVES This study was done to determine the spillover and extraction of endothelin-1 (ET-1) in the peripheral circulation, and to evaluate the fac tors that regulate local ET-1 extraction in the peripheral circulation in p atients with congestive heart failure (CHF). BACKGROUND The relationship between the spillover and extraction of the ET- 1 in the peripheral circulation and systemic vascular resistance (SVR) has not been fully clarified. METHODS We measured plasma levels of ET-1 both in femoral artery (FA) and f emoral vein (FV) in 93 patients with CHF. RESULTS Plasma ET-1 was significantly higher in FV than in FA in New York H eart Association (NYHA) functional class II patients, but there was no diff erence of ET-1 between FA and FV in functional class III patients. In patie nts with functional class IV, plasma ET-1 was significantly lower in FV tha n in FA, and SVR was significantly higher than in patients with NYHA class II or class III. Moreover, a significant positive correlation existed betwe en plasma ET-1 extraction across the lower leg and SVR in these patients. A mong the various neurohumoral factors and hemodynamics, plasma levels of ET -1, angiotensin II in the FA showed an independent and significant relation ship with the plasma arteriovenous difference of ET-1 in the lower limb. CONCLUSIONS Circulating ET-1 is extracted in peripheral circulation in pati ents with severe CHF, suggesting the possibility of upregulation of ET rece ptors of vascular beds in the lower limb in these patients. The peripheral extraction of ET-1 correlates with SVR in severe CHF patients and is mainly regulated by the local ET-1 and renin angiotensin systems. (C) 1999 by the American College of Cardiology.