[Age-related differences in the clinical symptoms and triggering factors among Chinese patients with acute myocardial infarction].

To analyze the age-related differences in the clinical symptoms and triggering factors among Chinese patients with acute myocardial infarction.Acute myocardial infarction Patients (n=14 854) registered in the China Acute Myocardial Infarction Registry from January 2013 to March 2014 were included in this study. Patients were divided into 4 groups: <55 years old group (3 950 patients), 55-64 years old group (4 361 patients), 65-74 years old group ( 3 759 patients), and ≥75 years old group (2 784 patients). Demographic features, medical history, clinical presentation and triggering factors were obtained via electronic data capture system.(1)Persistent chest pain and sweat were the major typical symptoms 66.4%(9 863/14 854) and 63.8%(9 471/14 854)) in the whole cohort. Prevalence of persistent chest pain among four groups were 73.8%(2 915/3 950), 69.2%(3 016/4 361), 63.6%(2 394/3 759) and 55.2%(1 538/2 784), and radiating pain among four groups were 36.2%(1 428/3 950), 34.1%(1 487/4 361), 30.9%(1 160/3 759)and 25.9%(722/2 784), and sweat among four groups were 70.0%(2 765/3 950), 66.5%(2 898/4 361), 61.8%%(2 323/3 759)and 53.3%(1 485/2 784), and there were statistical significance for all above symptoms among groups (all P<0.001). (2)triggering factors before acute myocardial infarction could be found in 19.4%(2 879/14 854) of the patients. Prevalence of existed triggering factors among four groups were 23.8%(941/3 950), 21.0%(914/4 361), 16.6%(625/3 759) and 14.3%(399/2 784, P<0.001). Recent excessive unhealthy lifestyles among four groups were 20.8%(196/3 950), 11.9%(109/4 361), 10.1%(63/3 759) and 9.0%(36/2 784) among the 4 groups (P<0.001).Persistent chest pain and sweat are absent in nearly half of Chinese patients in ≥75 years old group. Triggering factors prior to acute myocardial infarction could be evidenced in about twenty percent patients, and which are more often in young patients. Clinical Trail Registry: National Institutes of Health，NCT018746.