Impact of pre-hospital emergency in the management and prognosis of acute myocardial infarction.

INTRODUCTION: In recent decades pre-hospital emergency plans have been developed in Portugal, in order to improve the quality and efficiency of medical care in acute situations. However, the real impact of these measures in the treatment of acute coronary patients has not been thoroughly studied. OBJECTIVE: To evaluate the impact of pre-hospital emergency care (PHE) in the management and prognosis of patients admitted to hospital with acute myocardial infarction (AMI). POPULATION: Three hundred and eighty-one consecutive patients admitted to our hospital with AMI between 7/1/2001 and 12/31/2002. METHODS: The patients referred to the Emergency Department (ED) after PHE care were prospectively compared with other patients admitted with AMI (controls), in terms of clinical and demographic characteristics, initial ECG, time of symptoms-to-ED, symptoms-to-ECG, and door-to-needle/balloon, Killip class, in-hospital morbidity and mortality, ejection fraction (EF) at discharge, morbidity and mortality during the first year and EF after one year. RESULTS: Of the 51 patients (mean age 66, 57% male) of the PHE group, 55% (mean age 66, 64% male) presented ST elevation on admission ECG. Of the 330 patients (mean age 63 years, 70% male) of the control group, ST elevation was present in 41% (p = 0.05), mean age 59 years (p < 0.02), 77% male (NS). There were no significant differences between the groups when cardiovascular risk factors, cardiac event history and comorbidity were studied. Time of symptoms-to-ED (124 vs. 256 min) and symptoms-to-ECG (138 vs. 292 min) were shorter in the PHE group (p < 0.005 and < 0.003, respectively). Door-to-ECG time was 14 min vs. 36 min in the control group (p < 0.02). In patients with ST elevation, door-to-needle (77 vs. 105 min) and door-to-balloon (79 vs. 132 min) times were shorter after PHE (NS, p = 0.08). Overall, the time of symptoms-to-reperfusion was shorter in the PHE group. There were no differences in Killip class, in-hospital mortality or one-year mortality/morbidity. The prevalence of EF < 45% was lower in the PHE group, both at discharge (39 vs. 58%, p = 0.08) and on the first year echocardiogram (8.3 vs. 46%, p < 0.04). CONCLUSIONS: Compared to other patients with AMI, those admitted to the ED after PHE are older and more frequently present ST elevation. PHE has a significant impact in reducing the time between first symptoms and admission to the ED, first ECG and reperfusion therapy. In patients with ST elevation at admission, the prevalence of heart failure after one year was found to be significantly lower in the PHE group, revealing the positive impact of PHE care in AMI that persists after one-year follow-up.