[Epidemiology of avoidable delay in the treatment of acute myocardial infarct: study conducted by "GISSI" (Italian Group for the Study of Survival after Myocardial Infarct)].

AIM OF THE STUDY: The delay between onset of symptoms and coronary care unit admission is decisive in the outcome of patients with acute myocardial infarction. The objective of the GISSI-Avoidable Delay Study was to evaluate the influence of the factors that affect the delay in acute myocardial infarction treatment.

METHODS: This study was a nationwide multicentre case-control study conducted in Italy by the 118 Coronary Care Units (CCUs) participating in GISSI-network. The median and mean times in cases and controls were compared for decision time, home-to-hospital time, and in-hospital time, and the influence of several potential risk factors on the delay was evaluated by comparison of patients admitted more than 6 hours after onset of symptoms with those admitted within 6 hours after onset. Among 5301 patients with acute myocardial infarction, 590 who came to a coronary care unit after 12 hours were considered cases. Controls included 600 patients treated within 2 hours, 603 between 2 and 6 hours, and 466 between 6 and 12 hours.

RESULTS: The median decision time among cases was 50-fold higher than that of controls who presented within 2 hours. Home-to-hospital time and in-hospital time appeared to play a less important role. Considering the patient-related variables, the delay seemed to be significantly affected by advanced age, living alone, low intensity of initial symptoms, history of diabetes, strong pain at onset of the infarction, occurrence of symptoms at night, and involvement of a general practitioner.

CONCLUSIONS: These data suggest that interventions aimed at reducing the delay in acute myocardial infarction treatment should primarly focus on the help-seeking behaviour of patients.