Published Online
on May 21, 2007

A more recent version of this article appeared on June 12, 2007

This Article Full Text (PDF) All Versions of this Article: 115/23/2909    most recent CIRCULATIONAHA.106.679639v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ibanez, B. Articles by Badimon, J. J. Search for Related Content PubMed PubMed Citation Articles by Ibanez, B. Articles by Badimon, J. J. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Heart Attack Hazardous Substances DB METOPROLOL Related Collections Animal models of human disease Other Treatment CT and MRI Acute myocardial infarction

Submitted on November 27, 2006
Accepted on April 9, 2007

Early Metoprolol Administration Before Coronary Reperfusion Results in Increased Myocardial Salvage. Analysis of Ischemic Myocardium at Risk Using Cardiac Magnetic Resonance

Borja Ibanez MD, Susanna Prat-González MD, Walter S. Speidl MD, Gemma Vilahur DVM, PhD, Antonio Pinero MD, Giovanni Cimmino MD, Mario J. García MD, Valentin Fuster MD, PhD, Javier Sanz MD, and Juan J. Badimon PhD^*

From the Zena and Michael A. Wiener Cardiovascular Institute, Mount Sinai School of Medicine, New York, NY. Dr Vilahur currently is at the Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, UAB, Barcelona, Spain.

^* To whom correspondence should be addressed. E-mail: juan.badimon{at}mssm.edu.

Background---Blockers improve clinical outcome when administered early after acute myocardial infarction. However, whether -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.

Key words: imaging • magnetic resonance imaging • metoprolol • myocardial infarction

This article has been cited by other articles:

				D. P. O'Regan, R. Ahmed, C. Neuwirth, Y. Tan, G. Durighel, J. V. Hajnal, I. Nadra, S. J. Corbett, and S. A. Cook Cardiac MRI of myocardial salvage at the peri-infarct border zones after primary coronary intervention Am J Physiol Heart Circ Physiol, July 1, 2009; 297(1): H340 - H346. [Abstract] [Full Text] [PDF]

				M. Carlsson, J. F.A. Ubachs, E. Hedstrom, E. Heiberg, S. Jovinge, and H. Arheden Myocardium at risk after acute infarction in humans on cardiac magnetic resonance quantitative assessment during follow-up and validation with single-photon emission computed tomography. J. Am. Coll. Cardiol. Img., May 1, 2009; 2(5): 569 - 576. [Abstract] [Full Text] [PDF]

				D. P. O'Regan, R. Ahmed, N. Karunanithy, C. Neuwirth, Y. Tan, G. Durighel, J. V. Hajnal, I. Nadra, S. J. Corbett, and S. A. Cook Reperfusion Hemorrhage Following Acute Myocardial Infarction: Assessment with T2* Mapping and Effect on Measuring the Area at Risk Radiology, March 1, 2009; 250(3): 916 - 922. [Abstract] [Full Text] [PDF]

				M. G. Friedrich Tissue characterization of acute myocardial infarction and myocarditis by cardiac magnetic resonance. J. Am. Coll. Cardiol. Img., September 1, 2008; 1(5): 652 - 662. [Abstract] [Full Text] [PDF]

				A. E. Arai Using Magnetic Resonance Imaging to Characterize Recent Myocardial Injury: Utility in Acute Coronary Syndrome and Other Clinical Scenarios Circulation, August 19, 2008; 118(8): 795 - 796. [Full Text] [PDF]

				R. Ramaraj, M. B. Forman, E. K. Jackson, C. J. Lowenstein, B. Ibanez, G. Cimmino, J. J. Badimon, P. G. Korantzopoulos, J. A. Goudevenos, D. M. Yellon, et al. Myocardial Reperfusion Injury N. Engl. J. Med., December 6, 2007; 357(23): 2408 - 2410. [Full Text] [PDF]

				E. R. Bates Role of Intravenous -Blockers in the Treatment of ST-Elevation Myocardial Infarction: Of Mice (Dogs, Pigs) and Men Circulation, June 12, 2007; 115(23): 2904 - 2906. [Full Text] [PDF]