Evaluation of Tc-99m-labeled glycoprotein IIb/IIIa receptor antagonist DMP444 SPECT in patients with infective endocarditis.
OBJECTIVE
Infective endocarditis (IE) is characterized by aggregation of activated platelets, fibrin, and bacteria. DMP444, a high-affinity glycoprotein IIb/IIIa receptor antagonist, binds to the fibrinogen-binding domain of activated platelets, depicting a key feature of IE. Tc-99m DMP444 scintigraphy was studied in a group of patients with possible IE.


METHODS
Tc-99m DMP444 (600 MBq; 16 mCi) planar and SPECT images of the heart were recorded in patients with possible IE for as long as 6 hours after injection. Results were compared to echocardiography and the Duke classification.


RESULTS
Sixteen patients (age range, 37 to 78 years) participated. DMP444 imaging was positive on SPECT in five patients, and all had definite endocarditis (affecting both prosthetic and native valves). Eleven patients were DMP444 negative, seven with no proof of IE. The remaining four patients were classified as having IE, but three had been receiving adequate intravenous antibiotic regimens for > or = 2 weeks at the time of scintigraphy and one had Q-fever endocarditis.


CONCLUSIONS
DMP444 SPECT allows in vivo visualization of IE if it is performed within 1 to 2 weeks after the start of antibiotic treatment. Given the high affinity of DMP444 for activated platelets, the results indicate the involvement of activated platelets in early IE.
Brouwers
Frederieke M
FM
Department of Nuclear Medicine, University Medical Center Nijmegen, The Netherlands.
Oyen
Wim J G
WJ
Boerman
Otto C
OC
Barrett
John A
JA
Verheugt
Freek W A
FW
Corstens
Frans H M
FH
Van der Meer
Jos W M
JW
D000328:Adult; D000368:Aged; D004452:Echocardiography; D004697:Endocarditis, Bacterial / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides; D015609:Organotechnetium Compounds; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors*; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon
C411949:DMP 444; D009842:Oligopeptides; D015609:Organotechnetium Compounds; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D019275:Radiopharmaceuticals