Diagnostic value of perfusion cardiovascular magnetic resonance in patients with angina pectoris but normal coronary angiograms assessed by intracoronary acetylcholine testing.
BACKGROUND
Perfusion cardiovascular magnetic resonance (CMR) has a high sensitivity for the detection of significant coronary artery disease (CAD). However, the specificity of this method is lower than its sensitivity. The reason for this observation is hitherto unclear and has been either explained by 'false-positive' results or by microvascular dysfunction in patients without CAD.


OBJECTIVE
To evaluate whether pathological myocardial perfusion-CMR imaging in symptomatic patients without significant CAD is associated with coronary epicardial or microvascular dysfunction.


METHODS
In this retrospective study, 42 patients who presented with unstable angina pectoris underwent (a) an adenosine-stress perfusion-CMR study; (b) coronary angiography; (c) intracoronary acetylcholine (ACh) testing following coronary angiography with exclusion of significant CAD. The CMR protocol comprised cine imaging followed by adenosine first-pass perfusion imaging and late gadolinium enhancement-CMR. Diagnostic left ventriculography and multiplane coronary angiography were performed before intracoronary ACh testing.


RESULTS
An adenosine-induced, reversible subendocardial perfusion defect was detected in 22/42 patients (52%) without significant CAD. Coronary epicardial vasospasm was detected in 10/42 patients (24%) while microvascular dysfunction was found in 20/42 patients (48%). Patients with a reversible stress-induced perfusion defect had significantly more often a pathological coronary epicardial or microvascular vasoreaction (20/22; 91%) during intracoronary ACh testing than those without a perfusion defect (10/20; 50%; p<0.01). Univariate correlation analyses revealed a substantial association between a pathological ACh-testing result and a perfusion defect in the antecedent CMR study (r= +0.45; p<0.01).


CONCLUSIONS
Reversible perfusion defects depicted by perfusion-CMR in patients without significant CAD are mostly due to coronary epicardial or microvascular dysfunction, and correct interpretation of such perfusion-CMR results may enable targeted treatment.
Yilmaz
Ali
A
Division of Cardiology, Robert-Bosch-Krankenhaus, Auerbachstrasse 110, Stuttgart 70376, Germany. ali.yilmaz@rbk.de
Athanasiadis
Anastasios
A
Mahrholdt
Heiko
H
Voehringer
Matthias
M
Ong
Peter
P
Hill
Stefan
S
Kispert
Eva-Maria
EM
Seebo
Melanie
M
Sechtem
Udo
U
D000109:Acetylcholine / Q000008:administration & dosage; D000241:Adenosine; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000175:diagnosis*; D003287:Contrast Media; D017023:Coronary Angiography; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D012189:Retrospective Studies; D014665:Vasodilator Agents / Q000008:administration & dosage
D003287:Contrast Media; D014665:Vasodilator Agents; D019786:Gadolinium DTPA; D000241:Adenosine; D000109:Acetylcholine