An epicardial delivery of nitroglycerine by active hydraulic ventricular support drug delivery system improves cardiac function in a rat model.

We have used a novel active hydraulic ventricular support drug delivery system (ASD) device, which is a non-transplant surgical approach, can adhere to heart surface, and deliver the drug directly into the epicardium. This study is intended to compare the effect of administration of nitroglycerine (NTG) through ASD and intravenous injection on the ischemic injury during acute myocardial infarction (AMI). 30 male SD rats were allocated into five groups (n = 6): sham, AMI, I.V., ASD high dose (ASDH), and ASD low dose (ASDL) respectively. Ligation of the left anterior descending (LAD) coronary artery was performed to induce myocardial infarction. Electrocardiograms were monitored, and serum myoglobin (Mb) was assessed. Hemodynamics was observed on pre- and post-operation. Hematoxylin and eosin (H&E) staining was performed for histological diagnosis. In all model animals, ligation of LAD provoked ST segment elevation and Mb level augmentation. In ASDH group, Mb showed obvious decrease as compared with other treatment groups. Hemodynamic parameters showed significant improvement in ASDH and ASDL groups than the I.V. group. H&E staining showed that AMI group rats had wavy fibers and loss of transverse striations while ASD group rats had obvious improvement. Unlike the I.V. group, ASD group rats showed significant vasodilation. Therefore, delivery of NTG through ASD to the cardiomyocytes could improve the therapeutic efficacy. A novel effective route for local delivery of agents to manage AMI has been proved.