PLASMA-LEVELS OF CYCLIC-NUCLEOTIDES IN CHRONIC CONGESTIVE-HEART-FAILURE AND THEIR CLINICAL IMPLICATION

Plasma levels of cyclic nucleotides were determined by radioimmunoassay in 196 cardiac patients and 50 normal persons. Plasma levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) increased with the deterioration of cardiac function. The level of cGMP was correlated with the cardiothoracic ratio, ratio of pre-ejection period and left ventricular ejection time, the intracardiac diameter, left ventricular ejection fraction and left ventricular short axis shortening (r = 0.55, r = 0.50, r = 0.55, r = -0.53 and r = -0.50, respectively; P < 0.001). There were only weak correlations between the level of cAMP and the cardiothoracic ratio, the ratio of pre-ejection period and the left ventricular ejection time, left ventricular ejection fraction, and left ventricular short axis shortening (r = 0.35, r = 0.38, r = -0.28 and r = -0.3 1, respectively; P < 0.0 1). The correlations between cGMP and mean pulmonary artery pressure (r = 0.48; P < 0.05) and mean left atrial pressure (r = 0.55; P < 0.01) were also significant. In patients who had received cardioversion and valve replacement the plasma cGMP level decreased significantly. During the follow-up period, 29 of 108 patients died (26.9%), the initial plasma levels of cAMP and cGMP in the dead group were significantly higher than those in the survival group (27.41 +/- 1.13 and 31.11 +/- 3.33 vs. 21.56 +/- 0.60 and 17.45 +/- 1.05 nmol/l, respectively; P < 0.01). We concluded that the plasma concentrations of cyclic nucleotides were elevated in patients with congestive heart failure and could be used as useful parameters in evaluation of cardiac function, therapeutic effect and prognosis.