RENAL CIRCULATORY EFFECTS OF ADENOSINE IN PATIENTS WITH CHRONIC HEART-FAILURE

Objectives. We sought to study the renal circulatory effects of adenos ine in patients,with chronic congestive heart failure (CHF). Backgroun d. Renal blood flow (RBF) is often reduced in patients with chronic CH F and may lead to decreased renal function. The cause of reduced RBF i s multifactorial and involves systemic as well as local vasoregulatory mechanisms. Stimulation of renal adenosine A(1) receptors in animal m odels has resulted in a significant vasoconstriction of afferent and e fferent glomerular arterioles and deterioration of renal function. Alt hough adenosine serum levels have been shown to be elevated in patient s with CHF, their effect on the renal circulation in this patient popu lation has not been studied. Methods. Nine patients with CHF from left ventricular systolic dysfunction mere studied. The effects of adenosi ne at a dose of 10(-5) mol/liter infused directly into the main renal artery on heart rate, renal artery blood pressure, renal artery cross- sectional area (measured by intravascular ultrasound), renal Doppler b lood flow velocity (measured by a Doppler flow sire in the renal arter y), RBF and renal vascular resistance (RVR) were evaluated. Results. I nfusion of adenosine resulted in no significant effect on heart rate o r renal artery blood pressure but caused a substantial increase in RVR (11,204 +/- 1,469 to 31,494 +/- 3,911 dynes.s.cm(-5), p = 0.0005), wh ich led to a marked fall in RBF in every patient (mean values 376 +/- 36 to 146 +/- 22 ml/m(2), p 0.0002). These changes in RVR and RBF mere associated with no significant change in renal artery cross-sectional area (0.389 +/- 0.040 to 0.375 +/- 0.033 cm(2), p = 0.3). Conclusions . Stimulation of renal adenosine receptors in patients with CHF result s in marked renal vasoconstriction that leads to an important reductio n in RBF. Lack of change in renal artery cross sectional area suggests that adenosine affects intrarenal resistance blood vessels rather tha n large conductance vessels. These results may indicate a rationale fo r investigation of renal adenosine receptor blockade for enhancement o f RBF and improvement of renal function in patients with chronic CHF. (C) 1998 by the American College of Cardiology.