title: Role of Perfusion at Rest in the Diagnosis of Myocardial Infarction Using Vasodilator Stress Cardiovascular Magnetic Resonance.
abstract: In clinical practice, perfusion at rest in vasodilator stress single-photon emission computed tomography is commonly used to confirm myocardial infarction (MI) and ischemia and to rule out artifacts. It is unclear whether perfusion at rest carries similar information in cardiovascular magnetic resonance (CMR). We sought to determine whether chronic MI is associated with abnormal perfusion at rest on CMR. We compared areas of infarct and remote myocardium in 31 patients who underwent vasodilator stress CMR (1.5 T), had MI confirmed by late gadolinium enhancement (LGE scar), and coronary angiography within 6 months. Stress perfusion imaging during gadolinium first pass was followed by reversal with aminophylline (75 to 125 mg), rest perfusion, and LGE imaging. Resting and peak-stress time-intensity curves were used to obtain maximal upslopes (normalized by blood pool upslopes), which were compared between infarcted and remote myocardial regions of interest. At rest, there was no significant difference between the slopes in the regions of interest supplied by arteries with and without stenosis >70% (0.31 ± 0.16 vs 0.26 ± 0.15 1/s), irrespective of LGE scar. However, at peak stress, we found significant differences (0.20 ± 0.11 vs 0.30 ± 0.22 1/s; p <0.05), reflecting the expected stress-induced ischemia. Similarly, at rest, there was no difference between infarcted and remote myocardium (0.27 ± 0.14 vs 0.30 ± 0.17 1/s), irrespective of stenosis, but significant differences were seen during stress (0.21 ± 0.16 vs 0.28 ± 0.18 1/s; p <0.001), reflecting inducible ischemia. In conclusion, abnormalities in myocardial perfusion at rest associated with chronic MI are not reliably detectable on CMR images. Accordingly, unlike single-photon emission computed tomography, normal CMR perfusion at rest should not be used to rule out chronic MI.
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois.
authors.forename: Mita B
authors.initials: MB
authors.lastname: Patel
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois. Electronic address: vmoravi@bsd.uchicago.edu.
authors.forename: Victor
authors.initials: V
authors.lastname: Mor-Avi
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois.
authors.forename: Keigo
authors.initials: K
authors.lastname: Kawaji
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Nathan
authors.affiliation: Department of Medicine and Radiology, University of Virginia Health System, Charlottesville, Virginia.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Kramer
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois; Department of Radiology, University of Chicago Medical Center, Chicago, Illinois.
authors.forename: Roberto M
authors.initials: RM
authors.lastname: Lang
authors.affiliation: Department of Medicine, University of Chicago Medical Center, Chicago, Illinois; Department of Radiology, University of Chicago Medical Center, Chicago, Illinois.
authors.forename: Amit R
authors.initials: AR
authors.lastname: Patel
mesh_terms: D000241:Adenosine; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D055414:Myocardial Perfusion Imaging; D011687:Purines; D011720:Pyrazoles; D012146:Rest / Q000502:physiology*; D012189:Retrospective Studies; D014665:Vasodilator Agents
chemical_list: D011687:Purines; D011720:Pyrazoles; D014665:Vasodilator Agents; C430916:regadenoson; D000241:Adenosine