Cardiac angiotensin-converting enzyme activity in myocardial infarction

The cardiac renin-angiotensin system is regarded as an important modulator in the infarct heart. Little is known about their presence and regulation i n human hearts. We measured angiotensin-converting enzyme (ACE) and renin a ctivities at the aortic root and anterior interventricular vein (AIV) in 51 patients with previous myocardial infarction (MI): anterior wall MI in 31 and inferior wall MI in :20 and 33 control subjects. In the anterior wall M I group, the serum ACE activity was increased significantly in the AIV than in the aortic root (16.2 +/- 5.3 vs 15.3 +/- 5.0 nmol/min/ml, p < 0.001), whereas the activity was not different between the aortic root and AIV in t he control (14.4 +/- 3.7 vs 14.4 +/- 3.7 nmol/min/ml) and in the inferior w all MI (16.5 +/- 4.8 vs. 17.0 +/- 5.2 nmol/min/ml) groups. On the other han d, there was Inc. no significant difference in plasma renin activity betwee n the AIV and aortic root in the 3 groups (control group, 1.0 +/- 0.5 vs 1. 0 +/- 0.5 pg/ml/hour; anterior wall MI group, 1.3 +/- 0.8 vs 1.3 +/- 0.8 pg /ml/hour; inferior wall MI group, 1.2 +/- 0.7 vs 1.3 +/- 0.8 pg/ml/hour). T he difference in serum ACE activity between the AIV and aortic root had a s ignificant positive linear correlation with pulmonary capillary wedge press ure (r = 0.606, p < 0.001), and had a significant negative linear correlati on with left ventricular ejection fraction (r -0.620, p < 0.001) in the ant erior wall MI group. Serum ACE activity from the infarct region of the left ventricle was augmented in patients with MI, and the activity was increase d in proportion to the severity of left ventricular dysfunction, (C) 1999 b y Excerpta Medica, Inc.