Table 4.2 Dual antiplatelet therapy		COR	LOE
Reworded	For patients with minor IS and high-risk TIA who did not receive intravenous thrombolysis, dual antiplatelet therapy is initiated within 24 hours of symptom onset if their NIHSS score is <3. The recommended treatment regimen includes aspirin 100 mg/day and clopidogrel 75 mg/day (with a loading dose of 300 mg on the first day) for 21 days. Subsequently, the treatment can be switched to monotherapy with clopidogrel 75 mg/day for 90 days.	I	A
New recommendation	For patients with non-cardioembolic minor IS (NIHSS score ≤3) or high-risk TIA (ABCD2 score ≥4) who present within 24 hours of symptoms onset, it is recommended considering CYP2C19 genetic rapid testing to determine if the patient carries CYP2C19 LoF alleles. The results of this genetic testing will aid in selecting antiplatelet agents.	I	A
	The genetic subgroup analysis of the CHANCE study revealed that patients carrying CYP2C19 LoF alleles did not show a significant reduction in stroke recurrence when treated with clopidogrel plus aspirin compared with aspirin alone.93 There was an interaction between the treatment group and genetic variation. The PRINCE study found that in patients who had a stroke or TIA carrying CYP2C19 LoF alleles, early administration of ticagrelor with aspirin reduced platelet hyper-reactivity and lowered the risk of 90-day stroke recurrence (secondary outcome) compared with clopidogrel with aspirin.94
New recommendation	For patients with non-cardioembolic minor IS (NIHSS score ≤3) or high-risk TIA (ABCD2 score ≤4) who present within 24 hours of symptom onset, if CYP2C19 gene can be tested and the patient carries CYP2C19 LoF alleles, ticagrelor plus aspirin for 21 days (ticagrelor loading dose of 180 mg on the first day, followed by 90 mg two times per day), and continue with ticagrelor monotherapy (90 mg two times per day) for 90 days are recommended.	I	A
	The CHANCE-2 study found that among patients with minor stroke or high-risk TIA who carry CYP2C19 LoF (*2, *3) alleles, ticagrelor plus aspirin demonstrated superior efficacy in preventing stroke recurrence compared with clopidogrel plus aspirin (HR 0.77, 95% CI 0.64 to 0.94, p=0.008).6 The PRINCE study found that in patients who had a stroke or TIA carrying CYP2C19 LoF alleles, early administration of ticagrelor with aspirin reduced platelet hyper-reactivity and lowered the risk of 90-day stroke recurrence (secondary outcome) compared with clopidogrel with aspirin.94
New recommendation	For patients with moderate IS (NIHSS score of 4–5) who present within 24 hours of symptom onset, ticagrelor plus aspirin for 30 days (ticagrelor loading dose of 180 mg on the first day, followed by 90 mg two times per day) may reduce the risk of recurrent stroke and death within 30 days.	IIb	B
	The THALES study found that patients with moderate stroke (NIHSS score of 4–5) benefited from ticagrelor plus aspirin compared (NIHSS score ≤3) with aspirin alone, as opposed to patients with minor strokes, without an increased risk of intracranial bleeding or other severe bleeding events.95