Abstract 343: Poloxamer 188 Reduces the Infarct Size in Pigs Undergoing ST Elevation Myocadial infarction
Introduction: Poloxamer 188 (P188) is a synthetic surfactant known to stabilize the cell membrane integrity and thus minimizes reperfusion injury (RI). RI protection protects the myocardial loss due to reperfusion phase of myocardial infarction. We hypothesized that treatment with P188 at the beginning of reperfusion in acute ST elevation myocardial infarction (STEMI) reduces the infarct size.
Methods: Ten pigs underwent total occlusion of the middle left anterior descending artery with a 3.0x12mm balloon at 6 atmospheres for 40 minutes. EKG and angiogram confirmed the presence of STEMI. Amiodarone (40mg IV) was given before the STEMI to prevent fatal arrhythmias. We deflated the balloon at 40 min in the control group (n=5) and reperfused for 4 hours. In the P188 group (n=5), we administered a single bolus of 10gm of P188 immediately after balloon deflation, through the guide in the left main and subsequently 250mg/Kg of P188 was systemically infused over 4 hours of reperfusion. The area at risk (AAR), the infarct area (IA) and normal myocardium were stained by triphenyltetrazolium chloride and Evans blue, before euthanizing the animal. We harvested all hearts and weighed the left ventricle mass (LVM). The endpoint of the study was infarct size ratio (ISR); defined as IA/AAR. We cut the hearts in short axis to estimate the ISR by Photoshop®. We used unpaired t-test for statistical analysis.
Results: All animals survived the STEMI phase without complication. There was no significant difference in LVM between the control and P188 groups (106±9 vs. 102±6gm, P=0.7). AAR was similar in P188 and control groups (43%±6% vs. 47±4%, p=0.5). The ISR (Figure) was significantly reduced in P188 group vs. the control group (13±4% vs. 61±3%, p<0.0001).
Conclusion: The RI protection is an important step of myocardial protection in STEMI after reperfusion. P188 protects the cell membrane and reduces the infarct size when applied immediately after establishing flow to the coronary artery.
- © 2013 by American Heart Association, Inc.