Power of plasma N-terminal proatrial natriuretic factor to determine haemodynamics in patients with cardiac disease: relation to serum creatinine.

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 greater than or equal to 13, greater than or equal to 18 and greater than or equal to 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 mu mol/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.