Limitation of myocardial infarct expansion by reperfusion independent of myocardial salvage.

Abstract

Very early reperfusion after coronary occlusion can reduce infarct size and preserve left ventricular function. Whether later reperfusion is of benefit is unclear. We studied the effect of very early reperfusion with myocardial salvage and "late" reperfusion without myocardial salvage on infarct expansion and aneurysm formation. Sixty-eight rats underwent left coronary artery ligation and were randomized to 30 min reperfusion, 2 hr reperfusion, or permanent coronary artery ligation. The animals were killed and the hearts examined at 2 weeks. Thirty minute reperfusion reduced infarct size, extent of transmurality, and infarct expansion. Two hour reperfusion reduced neither infarct size nor transmurality but inhibited infarct expansion. The results of this study in the rat preparation suggest a beneficial effect of "late" reperfusion on infarct expansion independent of myocardial salvage. If these results are confirmed in human beings, the period after myocardial infarction during which a patient can be considered for thrombolytic therapy or reperfusion by percutaneous transluminal coronary angioplasty could be greatly prolonged.

Angiographically Documented Late Reocclusion After Successful Coronary Angioplasty of an Infarct-Related Lesion Is a Powerful Predictor of Long-Term Mortality

“…The mechanisms by which late reocclusion may independently affect long-term prognosis are not known specifically; as previously discussed, late reocclusion may interfere with left ventricular remodeling, electrical stability, and the availability of collaterals in the event of occlusion of a contralateral artery. 3,4,8,9 Nevertheless, despite similar baseline characteristics in patients with and without reocclusion, the design of our study does not allow us to exclude the hypothesis that late reocclusion may be a marker rather than the actual cause of late mortality.…”

“…1,2 Although this is explained in part by a beneficial effect on left ventricular function, some experimental and clinical studies suggest that reestablishing patency of the infarct-related artery (IRA) may have beneficial effects that are independent of myocardial salvage. [3][4][5][6][7] Possible mechanisms include reduction of ventricular remodeling, improvement in electrical stability, and provision of collaterals in the event of occlusion of a contralateral coronary artery. 3,4,8,9 Patency of the IRA, however, is a dynamic process.…”

“…[3][4][5][6][7] Possible mechanisms include reduction of ventricular remodeling, improvement in electrical stability, and provision of collaterals in the event of occlusion of a contralateral coronary artery. 3,4,8,9 Patency of the IRA, however, is a dynamic process. Angiographic studies have demonstrated frequent reocclusion of patent IRAs.…”

Injectable hydrogel properties influence infarct expansion and extent of postinfarction left ventricular remodeling in an ovine model

“…Future work will evaluate the impact of MeHA treatment time and infarct reperfusion status on LV remodeling. This MI model involves a permanent occlusion, which generally is associated with a more profound remodeling stimulus (34,35) than in reperfused infarct models that have been used to evaluate the impact of other injectable materials with reperfusion (17,25,36).…”

Remodelage précoce du ventricule gauche après un accident coronarien aigu

“…L'étendue de l'infarctus et son caractère transmural sont des déterminants essentiels du remodelage ventriculaire [29,30]. La réouverture précoce de l'artère occluse et la reperfusion tissulaire qui en découle limitent la taille de la zone infarcie et s'accompagnent d'un bénéfice clinique net en termes de mortalité, de survenue d'insuffisance cardiaque et d'arythmies [31].…”