Abstract

Background: The association between B-type natriuretic peptide (BNP) and coronary artery disease is not fully understood.

Objective: To assess whether ischaemia per se is a stimulus for BNP secretion.

Setting: University tertiary hospital, Spain (Virgen de la Arrixaca).

Design: Prospective interventional study.

Patients: 11 patients (55 (9) years, left ventricular ejection fraction (LVEF) 45% (7%) with a non-complicated anterior myocardial infarction (MI) and isolated stenosis of the left anterior descending (LAD) coronary artery, successfully treated by primary angioplasty.

Interventions: 11.0 (0.9) days after MI, the LAD was occluded (20 min) for intracoronary infusion of progenitor cells. Blood samples were obtained from the femoral artery (peripheral circulation (PC)) and the coronary sinus (coronary circulation (CC)) immediately before and after coronary occlusion.

Main outcome measures: BNP (pg/ml) was measured and ischaemia biomarkers were monitored.

Results: During coronary occlusion, all patients experienced transitory chest pain and ST-segment dynamic changes. After coronary occlusion, lactic acid levels rose in CC (1.42 (0.63) –1.78 (0.68) ng/ml, p = 0.003). Myoglobin and cardiac troponin T did not differ in CC or PC at 24 h. No differences were found in LVEF (+0.18% (2.4)%, p = 0.86) and motion score index (–0.02 (0.06), p = 0.37). Before occlusion, BNP levels did not differ significantly in CC versus PC (253 (56) vs 179 (34), p = 0.093). After occlusion, BNP showed a significant increase in CC (vs 332 (61), p = 0.004), but no change occurred in PC (vs 177 (23), p = 0.93), and circulating BNP levels were higher in CC versus PC (p = 0.008).

Conclusions: In response to acute ischaemia, BNP levels immediately increase in coronary sinus but not at the peripheral level. BNP release in the coronary effluent may exert local beneficial effects.