Objective: The aim was to examine the usefulness of plasma N-terminal proatrial natriuretic factor (N-terminal proANP) as a non-invasive marker of cardiac pressure in patients with normal to mildly elevated serum creatinine.
Methods: Blood samples were drawn at rest from 100 patients with cardiac disease undergoing diagnostic cardiac catheterization.
Results: Using multivariate analysis, N-terminal proANP was independently related to mean pulmonary capillary wedge pressure (PCWP), mean right atrial pressure, serum creatinine (s-creatinine) and cardiac index. These indices accounted for about 50% of the variation in N-terminal proANP. All patients with N-terminal proANP < 1000 pmol/l had normal PCWP (< 13 mmHg). Areas under the receiver-operating characteristic (ROC) curves for N-terminal proANP for the detection of PCWP > or = 13, > or = 18 and > or = 24 mmHg were 0.903, 0.870 and 0.876, respectively.
Conclusion: These results suggest that analysis of plasma N-terminal proANP is a simple and powerful method for assessing cardiac pressure in patients with heart disease and normal and mildly elevated s-creatinine (< 165 micromol/l). The value of N-terminal proANP cannot, however, indiscriminately be used to assess cardiac haemodynamics. N-terminal proANP measurement is a useful screening parameter for identifying patients with normal cardiac pressures.