Typical chest pain and onset of acute myocardial infarction in a prospective cohort of emergency calls

We read with interest the paper by Gupta et al in the August 2002 issue of Annals. In their retrospective, cross-sectional study over a 5-year period, only 53% (380/721) of patients diagnosed with acute myocardial infarction presented with chest pain. We have conducted a prospective study in Ferrara, Italy, from January 1998 to December 1999, based on the calls addressed to the Emergency Coordinating Unit. The organization of the Emergency Service in Ferrara, a town in northern Italy with approximately 150,000 inhabitants, is reported elsewhere. The only available hospital in this community is St. Anna Hospital, which serves as the sole teaching center for the School of Medicine. Emergency calls are addressed to the phone number 118 (the equivalent for 911 in the United States), referring to the Emergency Coordinating Unit located inside the hospital. The operator is a highly-trained nurse who, on the basis of a few quick but precise questions, makes a rough classification of emergency calls, identifies the level of severity and assigns the intervention to the nearest starting point of ambulances. Ambulances are strategically distributed throughout the territory, and the average time of arrival at the emergency department is within 15 minutes from the time the call is received. During the considered period, 221 patients (mean age 68±12.5 years) were diagnosed with myocardial infarction. Of these, 40 (mean age 67.8±12.5 years; 33 men) died in the ED. The remaining 181 (mean age 68.9±12.6 years; 127 men) were admitted to the hospital. Of the hospitalized patients, 90% (163) reported typical chest pain. The frequency of other complaints were diaphoresis, 47.5% (86); shortness of breath, 29.8% (54); nausea and vomiting, 20.4% (37); dizziness/syncope, 9.4% (17); and palpitations, 2.8% (5). Our percentage of patients presenting with chest pain (90%) is higher than the one (53%) reported by Gupta et al1 in their unselected cohort of patients presenting to the ED. An intermediate value (66%) was reported by the National Registry of Myocardial Infarction. A first consideration is that such differences could be related with the age of patients. In fact, our patients were significantly younger than those in the other 2 studies. This may be important for prognosis because prodromal angina shortly preceding myocardial infarction seems to be associated with a smaller infarct size and a better short- and long-term survival, but only in nonelderly patients. As concerns our sample, keeping in mind that the Health System in Italy is totally free, it appears to be important that a trained Emergency Coordinating Unit operator, in a few seconds, can reach a high level of precision in collecting symptoms from the patients. In the presence of paucity of economic resources, a precise evaluation of the level of severity permits prompt identification of the facilities needed (eg, ambulance with only paramedic staff, ambulance with physician aboard, helicopter) and a more rational use of them.