In the treatment of acute myocardial infarction (MI) reperfusion therapy significantly improves survival. However, an open epicardial coronary artery is not necessarily equivalent to optimal myocardial reperfusion. Despite a widely patent artery, complete reperfusion at the myocardial level may not occur because of occlusion of the microvasulature. The applicant has used contrast-enhanced magnetic resonance imaging (MRI) to document microvascular obstruction or """"""""no-reflow"""""""" in patients with reperfused acute MI and correlated it with adverse clinical outcomes. This proposal extends her prior work by applying MRI to the setting of elective percutaneous coronary interventions (PCI), an area in which microvascular obstruction has not been fully described.
Specific aims i nclude: (1) Determining the prevalence of microvascular obstruction by MRI after elective PCI; (2) Determining clinical risk factors for development and angiographic and cardiac enzyme correlates of microvascular obstruction; (3) Determining the time course of evolving microvascular obstruction by serial MRI from 2-4 hours to 24 hours to 6 months after PCI; (4) Correlating the presence and extent of microvascular obstruction with global and regional left ventricular function; and (5) Relating the presence and extent of microvascular obstruction to 3-5 year clinical outcome. This study will be performed at the Johns Hopkins Hospital, under the mentorship of Dr. Joao Lima, a leading expert in cardiovascular MRI. Johns Hopkins has extensive MRI facilities and a comprehensive research program that includes extensive collaboration between Cardiology and Radiology. In addition, the School of Public Health is world-renowned. Hence, Johns Hopkins provides the ideal environment for the applicant to achieve her goals of designing and performing clinical trials addressing the pathophysiology of coronary syndromes, using MRI as a tool to answer research questions in coronary syndromes, and expanding the clinical applicability of cardiac MRI.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
1K23HL004444-01
Application #
6190348
Study Section
Special Emphasis Panel (ZHL1-CSR-F (M1))
Project Start
2000-09-15
Project End
2005-08-31
Budget Start
2000-09-15
Budget End
2001-08-31
Support Year
1
Fiscal Year
2000
Total Cost
$128,218
Indirect Cost
Name
Johns Hopkins University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
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Strauss, David G; Selvester, Ronald H; Lima, Joao A C et al. (2008) ECG quantification of myocardial scar in cardiomyopathy patients with or without conduction defects: correlation with cardiac magnetic resonance and arrhythmogenesis. Circ Arrhythm Electrophysiol 1:327-36
Wu, Katherine C; Weiss, Robert G; Thiemann, David R et al. (2008) Late gadolinium enhancement by cardiovascular magnetic resonance heralds an adverse prognosis in nonischemic cardiomyopathy. J Am Coll Cardiol 51:2414-21
Schmidt, Andre; Azevedo, Clerio F; Cheng, Alan et al. (2007) Infarct tissue heterogeneity by magnetic resonance imaging identifies enhanced cardiac arrhythmia susceptibility in patients with left ventricular dysfunction. Circulation 115:2006-14
Luo, Albert K; Wu, Katherine C (2006) Imaging microvascular obstruction and its clinical significance following acute myocardial infarction. Heart Fail Rev 11:305-12
Schmidt, Andre; Wu, Katherine C (2006) MRI assessment of myocardial viability. Semin Ultrasound CT MR 27:11-9
Wu, Katherine C; Lima, Joao A C (2003) Noninvasive imaging of myocardial viability: current techniques and future developments. Circ Res 93:1146-58