Dual antiplatelet therapy in stroke and ICAS: Subgroup analysis of CHANCE.
AB OBJECTIVE: We aimed to investigate whether the efficacy and safety of clopidogrel plus aspirin vs aspirin alone were consistent between patients with and without intracranial arterial stenosis (ICAS), in the Clopidogrel in High-Risk Patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial.


METHODS
We assessed the interaction of the treatment effects of the 2 antiplatelet therapies among patients with and without ICAS, identified by magnetic resonance angiography (MRA) in CHANCE (ClinicalTrials.gov identifier NCT00979589).


RESULTS
Overall, 1,089 patients with MRA images available in CHANCE were included in this subanalysis, 608 patients (55.8%) with ICAS and 481 (44.2%) without. Patients with ICAS had higher rates of recurrent stroke (12.5% vs 5.4%; p<0.0001) at 90 days than those without. But there was no statistically significant treatment by presence of ICAS interaction on either the primary outcome of any stroke (hazard ratio for clopidogrel plus aspirin vs aspirin alone: 0.79 [0.47-1.32] vs 1.12 [0.56-2.25]; interaction p=0.522) or the safety outcome of any bleeding event (interaction p=0.277).


CONCLUSIONS
The results indicated higher rate of recurrent stroke in minor stroke or high-risk TIA patients with ICAS than in those without. However, there was no significant difference in the response to the 2 antiplatelet therapies between patients with and without ICAS in the CHANCE trial. Classification of evidence: This study provides Class II evidence that for patients with acute minor stroke or TIA with and without ICAS identified by MRA, clopidogrel plus aspirin is not significantly different than aspirin alone in preventing recurrent stroke.
Liping
L
Liu
Ka Sing Lawrence
KS
Wong
Xinyi
X
Leng
Yuehua
Y
Pu
Yilong
Y
Wang
Jing
J
Jing
Xinying
X
Zou
Yuesong
Y
Pan
Anxin
A
Wang
Xia
X
Meng
Chunxue
C
Wang
Xingquan
X
Zhao
Yannie
Y
Soo
S Claiborne
SC
Johnston
Yongjun
Y
Wang
D000368:Aged; D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D000077144:Clopidogrel; D003251:Constriction, Pathologic / Q000473:pathology; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D020765:Intracranial Arterial Diseases / Q000188:drug therapy* / Q000517:prevention & control; D002546:Ischemic Attack, Transient / Q000188:drug therapy* / Q000517:prevention & control; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology*; D012008:Recurrence; D020521:Stroke / Q000188:drug therapy* / Q000517:prevention & control; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin