[Relationship between brain natriuretic peptide and coronary stenosis: influence of aging]

The relationship between brain natriuretic peptide (BNP) and coronary stenosis, and the utility of BNP for the prediction of coronary stenosis were investigated.

This study included 100 consecutive patients (48 men, 52 women, mean age 65.8 +/- 9.9 years) who underwent elective cardiac catheterization for the diagnosis of coronary stenosis without other heart diseases (heart failure, valvular heart disease, cardiomyopathy, sick sinus syndrome), and E/A was recorded by echocardiography. The relationship between coronary stenosis, left ventricular ejection fraction by left ventriculography, left ventricular end-diastolic pressure, E/A, left ventricular stroke volume index by echocardiography and BNP were investigated.

Thirty-nine patients revealed coronary stenosis > or = 75% (CS), and 6 patients had chronic total occlusion. In the CS(+) group, BNP and left ventricular end-diastolic pressure were elevated significantly (50.7 +/- 48.5 vs 22.1 +/- 21.6 pg/ml, p < 0.05; 9.2 +/- 5.3 vs 6.4 +/- 3.4 mmHg, p < 0.05). In logistic regression analysis, BNP and left ventricular end-diastolic pressure had significant correlations with CS(+), independent of age, systolic blood pressure, E/A and left ventricular ejection fraction (p = 0.007, p = 0.05, respectively). Prognostic values of BNP (> 20 pg/ml) for the diagnosis of CS(+) were sensitivity of 79%, and specificity of 61% (p < 0.005). In the CS(-) group, the patients showing BNP > 20 pg/ml were older than the patients showing BNP < or = 20 pg/ml (68.4 +/- 8.5 vs 60.0 +/- 9.4, p < 0.05). Therefore, the prognostic values were reduced (sensitivity 78%, specificity 82%, p < 0.005) in the younger group (age < 65, n = 42). Even in patients with coronary stenosis but without chronic total occlusion, both BNP and left ventricular end-diastolic pressure were elevated significantly compared with the patients without coronary stenosis (22.1 +/- 21.6 vs 44.0 +/- 43.2 pg/ml, p < 0.01; 6.4 +/- 3.4 vs 9.1 +/- 5.2 mmHg, p < 0.01).

Plasma BNP levels are useful markers for detecting coronary stenosis, especially in younger patients.