Dipyridamole myocardial perfusion tomography in patients with severe aortic stenosis.
Patients with aortic stenosis (AS) may have classic angina pectoris. The safety of exercise testing in adults with AS is controversial and, in fact, exercise testing in such patients is considered to be contraindicated especially in severe aortic stenosis (SAS). Furthermore, exercise testing has low specificity in uncovering coronary artery disease (CAD) in patients with AS, because the baseline ECG is frequently abnormal. We wished to assess the safety and diagnostic accuracy of dipyridamole stress myocardial perfusion tomography (DMPT) in the detection of CAD in patients with SAS.


METHODS
The study included 30 patients with SAS (mean aortic valve area 0.57 +/- 0.09 cm(2)). All patients underwent dipyridamole myocardial perfusion scintigraphy (SPECT), coronary arteriography and catheterization, as well as Doppler echocardiography. Myocardial perfusion tomography was applied with (99m)Tc hexakis-2-methoxyisobutyl isonitrile (MIBI) by a single day rest-dipyridamole infusion protocol. Hemodynamic, electrocardiographic and clinical responses were compared with those of 50 control patients without AS.


RESULTS
Hemodynamic responses during dipyridamole stress tests demonstrated no significant differences between the controls and the AS patients in the following parameters: systolic blood pressure, heart rate, rate-pressure product or incidence of headache, chest pain, dyspnea, flushing and dizziness. A reversible perfusion defect was observed in 10 patients with DMPT. The existence of coronary lesions was determined by coronary arteriography in 8 of 10 patients (sensitivity 100%, specificity 91%).


CONCLUSIONS
The results showed that DMPT is well tolerated, even by patients with SAS and is of high diagnostic value in assessing CAD.
Demirkol
Mehmet Onur
MO
Department of Nuclear Medicine, Koşuyolu Heart and Research Hospital, Istanbul, Turkey. onurdemirkol@hotmail.com
Yaymaci
Bengi
B
Debeş
Hakan
H
Başaran
Yelda
Y
Turan
Fikret
F
D000368:Aged; D001024:Aortic Valve Stenosis / Q000150:complications* / Q000503:physiopathology*; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology; D004176:Dipyridamole / Q000009:adverse effects*; D004452:Echocardiography; D005080:Exercise Test / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion / Q000009:adverse effects*; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014054:Tomography / Q000009:adverse effects*; D015899:Tomography, Emission-Computed, Single-Photon
D010726:Phosphodiesterase Inhibitors; D004176:Dipyridamole