Abstract 12742: Low-Intensity Pulsed Ultrasound Enhances Angiogenesis and Ameliorates Left Ventricular Dysfunction in a Porcine Model of Chronic Myocardial Ischemia
Background: Despite recent advances in medical technology, the number of patients with severe ischemic heart disease (IHD) has been increasing.
It is therefore crucial to develop new, effective therapeutic strategies. In this study, we aimed to apply the low-intensity pulsed ultrasound (LIPUS) to the treatment of IHD.
Methods and Results: In cultured human vascular endothelial cells, the LIPUS (1, 16, 32, 48 and 64-cycle at the intensity of 250 mW/cm2 for 20 min) up-regulated mRNA expression of VEGF 3 hours after irradiation with a peak at 32-cycle LIPUS (P≤0.05) (Figure ). Based on this in vitro finding, we then examined the effects of LIPUS in a porcine model of chronic myocardial ischemia with an ameroid constrictor placed around the left circumflex coronary artery (n=18). The heart was treated with either sham or LIPUS (20-min irradiation with 32-cycle) at 3 different short axis levels 3 times a week. After 4 weeks, the reduced left ventricular ejection fraction (LVEF) was significantly improved in the LIPUS group (46±4 to 57±5%, P≤0.05), whereas it remained unchanged in the control group (46±5 to 47±6%, P=0.33) (Figure ). Capillary density in the ischemic area was significantly increased in the LIPUS group compared with the control group (1084±175 vs. 858±151 /mm2, P≤0.05). Regional myocardial blood flow in the ischemic area was also improved in the LIPUS group (0.78±0.2 to 1.39±0.4 ml/min/g, P≤0.05) but not in the control group. The protein expression of VEGF, eNOS and bFGF in the ischemic area was significantly enhanced in the LIPUS group compared with the control group. There were no adverse effects of the LIPUS study, such as myocardial injury and arrhythmias.
Conclusions: The LIPUS therapy ameliorates ischemia-induced LV dysfunction by enhancing angiogenesis and myocardial blood flow in the ischemic myocardium without any adverse effects, indicating that the LIPUS therapy is a promising strategy for the treatment of IHD.
- © 2013 by American Heart Association, Inc.