Objective To investigate the efficacy of double dose of clopidogrel in the treatment of acute myocardial infarction (AMI) in the elderly patients with ticagrelor CYP2C19 intermediate metabolism. Methods A total of 196 elderly patients with acute myocardial infarction were enrolled, who were admitted to the Cardiology Department in Beijing Shijitan Hospital from August 2016 to August 2018. All patients were found to be of CYP2C19 intermediate metabolism and randomized into the study group and control group (98 in each group). The two groups underwent percutaneous coronary intervention (PCI). The study group took oral clopidogrel at 300mg for the first time after surgery, then at 150mg once for three months before shifted to 75mg once. The control group took oral clopidogrel at 300mg for the first time after surgery and then at 75mg once. Both groups took medication once daily for 1 year. The two groups were compared in cardiac function related indicators and inflammatory factors interleukin-8 (IL-8) and C-reactive protein (CRP) levels before and after treatment as well as clinical efficacy, adverse reaction rate and recurrence rate. SPSS statistics 22.0 was used to analyze the data. Student′s t test or Chi-square test was employed for intergroup comparison. Results Compared with the control group after treatment, the study group had lower QRS [(4.74±0.81) vs (5.68±0.63) score], myocardial infarction [(13.86±2.47)% vs (17.23±3.02)%], cardiac troponin [(1.08±0.25) vs (3.12±0.77)μg/L], creatine kinase isoenzyme-MB[(45.82±8.45) vs (55.83±10.26)U/L], IL-8 [(39.54±8.22) vs (55.28±11.64)μg/L] and CRP[(5.22±0.86) vs(7.13±0.92) mg/L], but higher left ventricular ejection fraction [(52.90±5.83)% vs (44.93±5.46)%], the difference beingstatistically significant. The total effective rate was significantly higher in the study group than the control group [89.80%(88/98) vs78.57%(77/98)], but the incidence of adverse reactions [4.08%(4/98) vs 11.22%(11/98)] and recurrence rate [2.04%(2/98) vs 8.16%(8/98)] in the former was significantly lower than the latter, the differences being statistically significant. Conclusion Double dose of clopidogrel has a good clinical efficacy in the treatment of acute myocardial infarction in the elderly patients with ticagrelor CYP2C19 intermediate metabolism with low incidence of adverse reactions and recurrence rate.