BACKGROUND: Beta-blockers improve clinical outcome when administered early after acute myocardial infarction. However, whether beta-blockers actually reduce the myocardial infarction size is still in dispute. Cardiac magnetic resonance imaging can accurately depict the left ventricular (LV) ischemic myocardium at risk (T2-weighted hyperintense region) early after myocardial infarction, as well as the extent of necrosis (delayed gadolinium enhancement). The aim of this study was to determine whether early administration of metoprolol could increase myocardial salvage, measured as the difference between the extent of myocardium at risk and myocardial necrosis. METHODS AND RESULTS: Twelve Yorkshire pigs underwent a 90-minute left anterior descending coronary occlusion, followed by reperfusion. They were randomized to metoprolol (7.5 mg during myocardial infarction) or placebo. Global and regional LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance imaging studies performed 4 and 22 days after reperfusion in 10 survivors. Despite similar extent of myocardium at risk in metoprolol- and placebo-treated pigs (30.9% of LV versus 30.6%; P=NS), metoprolol resulted in 5-fold-larger salvaged myocardium (32.4% versus 6.2% of myocardium at risk; P=0.015). The LV ejection fraction significantly improved in metoprolol-treated pigs between days 4 and 22 (37.2% versus 43.0%; P=0.037), whereas it remained unchanged in pigs treated with placebo (35.1% versus 35.0%; P=NS). The extent of myocardial salvage was related directly to LV ejection fraction improvement (P=0.031) and regional LV wall motion recovery (P=0.039) at day 22. CONCLUSIONS: Early metoprolol administration during acute coronary occlusion increases myocardial salvage. The extent of myocardial salvage, measured as the difference between myocardium at risk and myocardial necrosis, was associated with regional and global LV motion improvement.
BACKGROUND: Beta-blockers improve clinical outcome when administered early after acute myocardial infarction. However, whether beta-blockers actually reduce the myocardial infarction size is still in dispute. Cardiac magnetic resonance imaging can accurately depict the left ventricular (LV) ischemic myocardium at risk (T2-weighted hyperintense region) early after myocardial infarction, as well as the extent of necrosis (delayed gadolinium enhancement). The aim of this study was to determine whether early administration of metoprolol could increase myocardial salvage, measured as the difference between the extent of myocardium at risk and myocardial necrosis. METHODS AND RESULTS: Twelve Yorkshire pigs underwent a 90-minute left anterior descending coronary occlusion, followed by reperfusion. They were randomized to metoprolol (7.5 mg during myocardial infarction) or placebo. Global and regional LV function, extent of myocardium at risk, and myocardial necrosis were quantified by cardiac magnetic resonance imaging studies performed 4 and 22 days after reperfusion in 10 survivors. Despite similar extent of myocardium at risk in metoprolol- and placebo-treated pigs (30.9% of LV versus 30.6%; P=NS), metoprolol resulted in 5-fold-larger salvaged myocardium (32.4% versus 6.2% of myocardium at risk; P=0.015). The LV ejection fraction significantly improved in metoprolol-treated pigs between days 4 and 22 (37.2% versus 43.0%; P=0.037), whereas it remained unchanged in pigs treated with placebo (35.1% versus 35.0%; P=NS). The extent of myocardial salvage was related directly to LV ejection fraction improvement (P=0.031) and regional LV wall motion recovery (P=0.039) at day 22. CONCLUSIONS: Early metoprolol administration during acute coronary occlusion increases myocardial salvage. The extent of myocardial salvage, measured as the difference between myocardium at risk and myocardial necrosis, was associated with regional and global LV motion improvement.
Authors: Hans Erik Bøtker; Derek Hausenloy; Ioanna Andreadou; Salvatore Antonucci; Kerstin Boengler; Sean M Davidson; Soni Deshwal; Yvan Devaux; Fabio Di Lisa; Moises Di Sante; Panagiotis Efentakis; Saveria Femminò; David García-Dorado; Zoltán Giricz; Borja Ibanez; Efstathios Iliodromitis; Nina Kaludercic; Petra Kleinbongard; Markus Neuhäuser; Michel Ovize; Pasquale Pagliaro; Michael Rahbek-Schmidt; Marisol Ruiz-Meana; Klaus-Dieter Schlüter; Rainer Schulz; Andreas Skyschally; Catherine Wilder; Derek M Yellon; Peter Ferdinandy; Gerd Heusch Journal: Basic Res Cardiol Date: 2018-08-17 Impact factor: 17.165
Authors: Karl H Schuleri; Andrew J Boyle; Marco Centola; Luciano C Amado; Robert Evers; Jeffrey M Zimmet; Kristine S Evers; Katherine M Ostbye; Diana G Scorpio; Joshua M Hare; Albert C Lardo Journal: Comp Med Date: 2008-12 Impact factor: 0.982
Authors: Declan P O'Regan; Rizwan Ahmed; Clare Neuwirth; Yvonne Tan; Giuliana Durighel; Joseph V Hajnal; Imad Nadra; Simon J Corbett; Stuart A Cook Journal: Am J Physiol Heart Circ Physiol Date: 2009-05-08 Impact factor: 4.733