Logistic regression analysis showed that smoking history (odds ratio (OR): 1.193, 95% confidence interval (CI): 1.002–1.422, p = 0.048), hypertension (OR: 3.371, 95% CI: 2.914–3.898, p < 0.001), diabetes mellitus (OR: 1.911, 95% CI: 1.632–2.237, p < 0.001), CYP2C19 intermediate metabolizer (IM) + poor metabolizer (PM) phenotypes (OR: 1.424, 95% CI: 1.243–1.631, p < 0.001), and dyslipidemia (OR: 1.294, 95% CI: 1.077–1.554, p = 0.006) were independent risk factors for premature CI. The gene discussed is CYP2C19; the disease is diabetes mellitus.