Thromboembolic complications in patients with clopidogrel resistance after coil embolization for unruptured intracranial aneurysms.
OBJECTIVE
Antiplatelet resistance is known to be associated with symptomatic ischemic complication after endovascular coil embolization. The purpose of our study was to evaluate the relationship between antiplatelet resistance and clinically silent thromboembolic complications using DWI in patients who underwent coil embolization for unruptured intracranial aneurysm.


METHODS
Between October 2011 and May 2013, 58 patients with 62 unruptured aneurysms who were measured for antiplatelet response using VerifyNow assay and underwent elective coil embolization for an unruptured aneurysm with posttreatment DWI were enrolled. Diffusion-positive lesions were classified into 3 groups according to the number of lesions (n=0 [grade 0], n<6 [grade I], and n≥6 [grade II]). The relationship between antiplatelet resistance and diffusion-positive lesions was analyzed.


RESULTS
Sixty-two endovascular coiling procedures were performed on 58 patients. Clopidogrel resistance was revealed in 23 patients (39.7%) and diffusion-positive lesions were demonstrated in 28 patients (48.3%); these consisted of 19 (32.8%) grade I and 9 (15.5%) grade II lesions. Clopidogrel resistance was not relevant to the development of any diffusion-positive lesion (grade I and II, P=.789) but was associated with the development of multiple diffusion-positive lesions (grade II, P=.002). In the logistic regression prediction model, clopidogrel resistance showed significant correlation with the development of grade II lesions (P=.001).


CONCLUSIONS
Multiple diffusion-positive lesions (≥6 in number) occurred more frequently in patients with clopidogrel resistance after endovascular coiling for unruptured aneurysms.
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
B
B
Kim
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.) somatom.kim@samsung.com.
K
K
Kim
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
P
P
Jeon
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
S
S
Kim
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
H
H
Kim
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
H
H
Byun
From the Departments of Radiology (B.K., K.K., P.J., S.K., H.K., H.B., J.C.).
J
J
Cha
Neurosurgery (S.H., K.J.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
S
S
Hong
Neurosurgery (S.H., K.J.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
K
K
Jo
D000328:Adult; D000368:Aged; D001807:Blood Vessel Prosthesis; D000077144:Clopidogrel; D038524:Diffusion Magnetic Resonance Imaging; D004351:Drug Resistance; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000379:methods; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D013923:Thromboembolism / Q000453:epidemiology* / Q000209:etiology* / Q000517:prevention & control; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine