Presence and severity of coronary artery disease and changes in B-type natriuretic peptide levels in patients with a normal systolic function

B-type brain natriuretic peptide (BNP) levels increase during myocardial ischemia. Here, the authors undertook to evaluate the correlation between changes in plasma BNP levels during exercise and the presence and severity of coronary artery disease (CAD). The study subjects consisted of 159 hospitalized patients with a normal systolic function. Patients were allocated to a control group (N = 101, comprising patients with coronary artery stenosis of < 50%) or to a CAD group (N = 58, comprising patients with stenosis of ≥ 50% or a greater coronary artery lesion). In addition, the CAD group was further subdivided into a single-vessel disease (VD) subgroup (N = 31) and a multi-VD subgroup (N = 27). All 159 study subjects underwent coronary angiography (CAG), and plasma BNP levels were measured before and immediately after exercise. A comparative study of BNP levels in the control and CAD groups before and after exercise revealed that BNP levels in the CAD group were significantly higher [22.4 (5.0-28.5) vs. 54.3 (13.1-74.6), P = 0.000; 35.0 (6.2-37.6) vs. 82.5 (23.2-102.8) pg/mL, P = 0.002, respectively]. Changes in BNP levels during exercise in the CAD group tended to be greater than in the control group, but without significance [12.6 (0-13.6) vs. 28.3 (2.8-25.5) pg/mL; P = 0.083]. Subgroup analysis showed that BNP levels tended to be positively related to the proportion of disease vessels, but statistical significance was only found between the control and multi-VD subgroup. Summarizing, this study shows that BNP level changes caused by exercise are closely related with the presence of CAD in patients with a normal systolic function. However, the relationship between these level changes and CAD severity requires further evaluation.