Giuseppe Berton, Rocco Cordiano, Rosa Palmieri, Gianluigi Guarnieri, Maria Stefani, Paolo Palatini

Background.The pre-hospital time delay in acute myocardial infarction (AMI) is still a challeng-ing problem since for many patients there are long intervals between the onset of symptoms and the initiation of therapy. The aim of this study was to verify which, among several clinical variables, areassociated with a prolonged pre-hospital time delay.

Methods. Five hundred and twenty-six unselected patients with AMI and consecutively admittedto three coronary care units were enrolled. The pre-hospital time delay was defined as the time inter-val from the onset of symptoms to admission to the coronary care unit. Clinical variables included:age, gender, body mass index, level of education, alcohol consumption, smoking habits, regular phys-ical  activity,  history  of  hypertension,  diabetes  mellitus,  history  of  coronary  artery  disease  (docu-mented history of angina and/or previous myocardial infarction), chronic atrial fibrillation, Q-waveAMI and off hours onset of symptoms. After univariate analysis, multivariable regression analysiswas used.

Results.The mean age of the patients was 66.6 ± 12.1 years and 28.7% were female. The medianpre-hospital time interval was 200 min (95% confidence interval 60-1140). For 342 patients the pre-hospital time interval was ≤6 hours and for 184 patients it was > 6 hours. Those variables which, atunivariate analysis, were found to significantly influence the pre-hospital delay were analyzed usinga  multivariable  regression  model  where  the  dependent  variable  was  the  pre-hospital  time  interval.Chronic atrial fibrillation (p = 0.010), a history of coronary artery disease (p = 0.017), diabetes (p =0.016) and age ≥70 years (p = 0.009) were found to be independently associated with a prolonged pre-hospital time interval. Similar results were obtained when considering only Q-wave AMI. As expect-ed, the thrombolytic therapy rate was much lower in patients with a longer pre-hospital time delay.

Conclusions.The present study shows that, in case of AMI, the time interval between the onset ofsymptoms and a patient’s arrival to hospital is still far from being optimal. This is especially true forolder patients with diabetes, a history of coronary artery disease or chronic atrial fibrillation. Cardi-ologists should be aware of this problem and should implement adequate educational strategies ad-dressed to those patients at highest risk.

Italian Heart J, 2001;2(10):766-771.

Key Words: Acute myocardial infarction; Pre-hospital time delay; Thrombolysis.