Objectives To investigate the pathophysiological role of adrenomedullin in myocardial infarction.

Patients and design Plasma concentrations of adrenomedullin, atrial natriuretic factor, and brain natriuretic peptide were measured by radioimmunoassay in 31 patients with acute myocardial infarction over four weeks, and in 44 normal subjects.

Results In patients with acute myocardial infarction, plasma adrenomedullin reached a peak of (mean (SD) 14.0 (9.0) pmol/l at 24 hours after the onset of symptoms and remained increased at all sampling points except the four week point compared with the value in normal subjects (5.0 (2.0) pmol/l). Adrenomedullin concentrations on admission were higher in patients from Killip class II, III, and IV than class I, and correlated positively with peak plasma creatine kinase and left ventricular end diastolic volume index, and negatively with left ventricular ejection fraction. The values from 12 to 48 hours were negatively correlated with systemic vascular resistance index. During the time course studied, adrenomedullin concentrations were positively correlated with atrial natriuretic factor (r = 0.40, p < 0.001) and brain natriuretic peptide (r = 0.53, p < 0.001).

Conclusions Plasma adrenomedullin concentrations increased in the acute phase of myocardial infarction in proportion with clinical severity, suggesting that adrenomedullin may play an important role in the pathophysiology of myocardial infarction.