[Establishment and characterization of a minipig model of microvascular coronary artery spasm].

OBJECTIVE: To observe the feasibility of establishing a porcine model of microvascular coronary artery spasm by intracoronary neuropeptide Y (NPY) infusion, and to analyze the characterization of this model.

METHODS: Minipigs were divided into four groups (n = 4 each): normal saline (NS) group, 1 nmol NPY group, 3 nmol NPY group, and 6 nmol NPY group. Arterial sheaths were planted into bilateral femoral arteries of minipigs. A pigtail catheter was placed at the left sheath to determine the hemodynamic parameters. NS and different doses of NPY were injected into the left anterior descending branch through the right sheath. Intravenous myocardial contrast echocardiography (MCE) was applied to measure the microvessel volume (α), filling velocity (β), and microcirculation blood flow (MBF) before and at 10 and 30 minutes after NS and NPY injection.

RESULTS: Before and after injection, there were no difference in α, β and MBF between NS and 1 nmol NPY group (all P > 0.05). In 3 nmol NPY group, α and MBF decreased at 10 min (P < 0.01 and 0.05, respectively), which were recovered at 30 min except α. Reductions of β (P < 0.05) and MBF (P < 0.01) were observed at 10 min in 6 nmol NPY group, which were recovered at 30 min, but MBF still remained lower than at baseline (P < 0.01) and compared to 3 nmol NPY group (P < 0.05).

CONCLUSION: Intracoronary injection of NPY into the anterior descending coronary artery can establish the porcine model of microvascular coronary artery spasm, which might serve as a useful animal model for coronary microvascular studies.