A meta-analysis of nine randomized clinical trials (61,623 patients) comparing P2Y12 inhibitors (five trials with clopidogrel and four trials with ticagrelor) to aspirin for secondary prevention of cardiovascular events found a significantly lower MACE risk (risk ratio, 0.89; 95% CI 0.84–0.95) and MI risk (risk ratio, 0.81; 95% CI 0.71–0.92), as well as a non-significant lower risk of stroke (risk ratio, 0.85; 95% CI 0.73–1.01) and major bleeding (risk ratio, 0.94; 95% CI 0.72–1.22) with P2Y12 inhibitors [66]. This evidence concerns the gene P2RY12 and stroke disorder.