Dipyridamole scintigraphy and intravascular ultrasound after successful coronary intervention.
Despite angiographically successful interventions, perfusion defects are not uncommonly observed in postinterventional perfusion scintigrams. The aim of this study was to test the hypothesis that perfusion defects after coronary intervention are associated with a significant residual stenosis in the treated vessel segment detectable by intravascular ultrasound but not by angiography.


METHODS
Forty consecutive patients with angiographically successful coronary interventions were prospectively studied by intravascular ultrasound immediately after the intervention. Within 48 hr after the intervention all patients had myocardial scintigraphy using 99mTc-methoxyisobutyl-isonitrile SPECT after dipyridamole stress. Myocardial perfusion defects in the scintigram were assigned to a segmental left ventricular model and compared to the perfusion territory of the treated vessel estimated from the coronary angiogram.


RESULTS
Twenty of 40 patients had reversible myocardial perfusion defects. Mean ultrasound area stenosis was 50% in these patients and 33% in patients without perfusion defects (p < 0.002); ultrasound percent plaque area was 75% versus 63% (p < 0.0001), respectively. The best concordance between residual area stenosis and perfusion defects was found for an ultrasound area stenosis > or = 40%.


CONCLUSIONS
Patients with stress-induced myocardial perfusion defects immediately after successful coronary intervention show high-grade residual stenoses that are more pronounced in patients with perfusion defects than in patients with normal postinterventional scintigrams. In addition, vessels serving myocardial regions with perfusion defects showed a significantly higher plaque burden indicating diffuse atherosclerotic changes in the vessel. The evaluation of the postprocedural result by intravascular ultrasound contributes to a better understanding of the discrepancy between the angiographic finding of a widely patent vessel but scintigraphic evidence of impaired perfusion.
Bachmann
R
R
Department of Nuclear Medicine, University of Cologne, Germany.
Sechtem
U
U
Voth
E
E
Schröder
J
J
Höpp
H W
HW
Schicha
H
H
D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003326:Coronary Circulation; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000628:therapy; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015607:Stents; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D018084:Ultrasonography, Interventional
D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi