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494 Effect of ischemic postconditioning on infarct size evaluated by magnetic resonance imaging in patients treated with Primary Percutaneous Coronary Intervention
S241
Abstracts
myocardium perfused by that artery from a subsequent episode of sustained ischemia. This phenomenon can be induced by pharmacological agents. Tumor Necrosis Factor-alpha (TNF), a multifunctional cytokine, could mimic ischemic preconditioning and thus lead to cardioprotection. However, its cardioprotective effect remains controversial. For that reason, we developed a porcine myocardial infarction model to assess the role of TNF in the preconditioning phenomenon. MATERIAL AND METHODS: Male pigs (n ⫽ 25) (35-40kg) were used for this study. The pigs underwent myocardial infarction by occlusion of left anterior descending (LAD) artery just distal to the second diagonal branch by inflated balloon catheter during a 50 minute period. After this period, the balloon was deflated and a three hour period of reperfusion was allowed. Myocardial infarction size (IS) which is the ratio of area of necrosis and area at risk was calculated by coloration method with Triphenyltetrazolium chlorure and Evans blue once animal sacrifice after the reperfusion period. Four different groups were performed during that study. In the placebo group (P), normal saline was injected 15 minutes before the ischemiareperfusion (IR) period in the coronary artery just at the level of occlusion. Two different doses (0.1 g/kg (TNF 0.1) and 1 g/kg (TNF 1)) of TNF were given 15 minutes before the IR period in the coronary artery just at the level of occlusion. In the IPC group, brief occlusions (four times, each time 1 minute) were performed before the IR period. RESULTS: There were significant differences in the IS between the TNF (0.1 and 1) and PC versus placebo group (see table). Moreover, there are no significant differences between TNF (0.1 or 1) versus PC (P ⫽ 0.388) and TNF 0.1 versus TNF 1 (P ⫽ 0.206).
We observed a significant decrease of IS in the IPC group and groups treated with TNF (0.1 or 1). These results demonstrate a similar cardioprotective effect of TNF as compared to IPC in a porcine model of myocardial infarction.
CONCLUSION:
494 EFFECT OF ISCHEMIC POSTCONDITIONING ON INFARCT SIZE EVALUATED BY MAGNETIC RESONANCE IMAGING IN PATIENTS TREATED WITH PRIMARY PERCUTANEOUS CORONARY INTERVENTION N Dwyer, Y Mikami, J Hubacek, M Traboulsi, M Friedrich, T Anderson Calgary, Alberta
The benefits of ischemic postconditioning limiting myocardial infarct size in the clinical setting are uncertain. Postconditioning is a sequence of repetitive interruptions of coronary blood flow following reperfusion. We tested the hypothesis that ischemic postconditioning would lead to a reduction in infarct size in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PPCI). METHODS: Sixty-five patients (median age 58 yrs; 88% male) with chest pain ⱕ 6 hours, ST-elevation, no previous myocardial infarction, ⬍ ⫽ TIMI 1 flow and Rentrop collateral grade ⬍ ⫽ 1 of the infarct related artery eligible for PPCI were included. The patients were randomized to standard PCI (n ⫽ 34) or 4 cycles of 30 seconds reperfusion and 30 seconds of re-occlusion before permanent reperfusion (n ⫽ 31). The endpoint of infarct size, expressed as a percentage of myocardium at risk, was determined on day 3 with delayed gadolinium enhancement and T2-weighted cardiac magnetic resonance imaging. Data are expressed as mean ⫾ SD. RESULTS: The infarct size, expressed as a percentage of myocardium at risk, in the postconditioned group was smaller (56.7 ⫾ 22.3%) than in the standard group (65.8 ⫾ 19.4%), but did not reach statistical significance (P ⫽ 0.08). The impact of postconditioning was independent of the size of myocardium at risk and location of the culprit lesion. The LV ejection fraction was greater in the postconditioned than standard group, 55.7 ⫾ 9.0% and 51.7 ⫾ 10.3% respectively, but did not reach statistical significance (P ⫽ 0.08). Peak CK, total CK release, myocardial blush grade, final TIMI flow grade, corrected TIMI frame count, percentage ST-segment resolution and amount of residual ST-segment deviation did not differ significantly between the groups. CONCLUSION: Postconditioning, in addition to PPCI, leads to an early 14% relative reduction in infarct size, which did not reach statistical significance due to lack of statistical power. The clinical benefits of postconditioning are reflected in the 4% absolute improvement of LVEF and warrant further investigation with a multicenter trial. BACKGROUND:
495 EFFECTS OF RECONSTITUTED HDL INFUSIONS ON EARLY ENDOTHELIAL PROGENITOR CELL DEATH AND SERUM STROMAL-DERIVED FACTOR-1 LEVELS CY Lee, E Rhéaume, C Berry, A Kernaleguen, G Brand, L Boileau, G Théberge-Julien, J Grégoire, R Ibrahim, P L’Allier, JC Tardif Montréal, Québec BACKGROUND: The Effect of rHDL on Atherosclerosis Safety and Efficacy (ERASE) trial was a randomized, double-blind, placebo (PLB)-controlled trial which evaluated 4 weekly iv. infusions of reconstituted HDL (rHDL) on plaque burden in patients with recent acute coronary syndromes (ACS). A significant reduction in atheroma volume was observed with rHDL but not with PLB (JAMA 2007). Moreover, in the ERASE
Abstracts
myocardium perfused by that artery from a subsequent episode of sustained ischemia. This phenomenon can be induced by pharmacological agents. Tumor Necrosis Factor-alpha (TNF), a multifunctional cytokine, could mimic ischemic preconditioning and thus lead to cardioprotection. However, its cardioprotective effect remains controversial. For that reason, we developed a porcine myocardial infarction model to assess the role of TNF in the preconditioning phenomenon. MATERIAL AND METHODS: Male pigs (n ⫽ 25) (35-40kg) were used for this study. The pigs underwent myocardial infarction by occlusion of left anterior descending (LAD) artery just distal to the second diagonal branch by inflated balloon catheter during a 50 minute period. After this period, the balloon was deflated and a three hour period of reperfusion was allowed. Myocardial infarction size (IS) which is the ratio of area of necrosis and area at risk was calculated by coloration method with Triphenyltetrazolium chlorure and Evans blue once animal sacrifice after the reperfusion period. Four different groups were performed during that study. In the placebo group (P), normal saline was injected 15 minutes before the ischemiareperfusion (IR) period in the coronary artery just at the level of occlusion. Two different doses (0.1 g/kg (TNF 0.1) and 1 g/kg (TNF 1)) of TNF were given 15 minutes before the IR period in the coronary artery just at the level of occlusion. In the IPC group, brief occlusions (four times, each time 1 minute) were performed before the IR period. RESULTS: There were significant differences in the IS between the TNF (0.1 and 1) and PC versus placebo group (see table). Moreover, there are no significant differences between TNF (0.1 or 1) versus PC (P ⫽ 0.388) and TNF 0.1 versus TNF 1 (P ⫽ 0.206).
We observed a significant decrease of IS in the IPC group and groups treated with TNF (0.1 or 1). These results demonstrate a similar cardioprotective effect of TNF as compared to IPC in a porcine model of myocardial infarction.
CONCLUSION:
494 EFFECT OF ISCHEMIC POSTCONDITIONING ON INFARCT SIZE EVALUATED BY MAGNETIC RESONANCE IMAGING IN PATIENTS TREATED WITH PRIMARY PERCUTANEOUS CORONARY INTERVENTION N Dwyer, Y Mikami, J Hubacek, M Traboulsi, M Friedrich, T Anderson Calgary, Alberta
The benefits of ischemic postconditioning limiting myocardial infarct size in the clinical setting are uncertain. Postconditioning is a sequence of repetitive interruptions of coronary blood flow following reperfusion. We tested the hypothesis that ischemic postconditioning would lead to a reduction in infarct size in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PPCI). METHODS: Sixty-five patients (median age 58 yrs; 88% male) with chest pain ⱕ 6 hours, ST-elevation, no previous myocardial infarction, ⬍ ⫽ TIMI 1 flow and Rentrop collateral grade ⬍ ⫽ 1 of the infarct related artery eligible for PPCI were included. The patients were randomized to standard PCI (n ⫽ 34) or 4 cycles of 30 seconds reperfusion and 30 seconds of re-occlusion before permanent reperfusion (n ⫽ 31). The endpoint of infarct size, expressed as a percentage of myocardium at risk, was determined on day 3 with delayed gadolinium enhancement and T2-weighted cardiac magnetic resonance imaging. Data are expressed as mean ⫾ SD. RESULTS: The infarct size, expressed as a percentage of myocardium at risk, in the postconditioned group was smaller (56.7 ⫾ 22.3%) than in the standard group (65.8 ⫾ 19.4%), but did not reach statistical significance (P ⫽ 0.08). The impact of postconditioning was independent of the size of myocardium at risk and location of the culprit lesion. The LV ejection fraction was greater in the postconditioned than standard group, 55.7 ⫾ 9.0% and 51.7 ⫾ 10.3% respectively, but did not reach statistical significance (P ⫽ 0.08). Peak CK, total CK release, myocardial blush grade, final TIMI flow grade, corrected TIMI frame count, percentage ST-segment resolution and amount of residual ST-segment deviation did not differ significantly between the groups. CONCLUSION: Postconditioning, in addition to PPCI, leads to an early 14% relative reduction in infarct size, which did not reach statistical significance due to lack of statistical power. The clinical benefits of postconditioning are reflected in the 4% absolute improvement of LVEF and warrant further investigation with a multicenter trial. BACKGROUND:
495 EFFECTS OF RECONSTITUTED HDL INFUSIONS ON EARLY ENDOTHELIAL PROGENITOR CELL DEATH AND SERUM STROMAL-DERIVED FACTOR-1 LEVELS CY Lee, E Rhéaume, C Berry, A Kernaleguen, G Brand, L Boileau, G Théberge-Julien, J Grégoire, R Ibrahim, P L’Allier, JC Tardif Montréal, Québec BACKGROUND: The Effect of rHDL on Atherosclerosis Safety and Efficacy (ERASE) trial was a randomized, double-blind, placebo (PLB)-controlled trial which evaluated 4 weekly iv. infusions of reconstituted HDL (rHDL) on plaque burden in patients with recent acute coronary syndromes (ACS). A significant reduction in atheroma volume was observed with rHDL but not with PLB (JAMA 2007). Moreover, in the ERASE