Epidemiology of acute myocardial infarction in the Italian CCU network: the BLITZ study.

AIMS: A large number of descriptive data on patients with acute myocardial infarction are based on clinical trials and registries on non consecutive patients: these data may give only a partial picture on treatment delay, patient characteristics, treatment and outcome of acute myocardial infarction in the real world. METHODS AND
RESULTS: The BLITZ survey prospectively enrolled all of the patients with acute myocardial infarction admitted in 296 (87%) Italian Coronary Care Units from 15-29 October 2001. Data on treatment delay, therapeutic strategies, duration of hospitalization and 30-day outcome were collected. One thousand nine hundred and fifty-nine consecutive patients (mean age 67+/-12 years, 70% males) were enrolled, 65% with ST-segment elevation (STEMI), 30% with no ST-segment elevation (NSTEMI) and 5% with undetermined ECG. The median delay between symptom onset and hospital arrival was 2h and 9 min with 76% of patients hospitalized within the sixth hour (26% within the first hour, 48% within the second). The median delay from hospital arrival to reperfusion therapy in STEMI was 45 min (IQR 26-85) for thrombolysis (50% of the patients) and 85 min (IQR 60-135) for primary angioplasty (15% of the patients). Coronary angiography was performed during hospital stay in 46% of the patients (STEMI 48%, NSTEMI 43%, undetermined AMI 35%), coronary angioplasty in 25% (STEMI 26%, NSTEMI 15%, undetermined AMI 13%) and coronary bypass in 1.4% (1%, 2.2% and 1% respectively). Twenty-two percent of the patients admitted to hospitals without cath-lab were transferred to a tertiary care hospital for invasive procedures. The overall median hospital stay was 10 days (IQR 7-12, STEMI 10, NSTEMI 9, undetermined AMI 11) and was not significantly different between hospitals with or without cath-lab (respectively, 9 and 10 days, P=0.38). After discharge and up to 30 days, coronary angiography was performed in 11% (STEMI 11%, NSTEMI 11%, undetermined MI 9%), angioplasty in 10% (STEMI 10%, NSTEMI 11%, undetermined MI 7%), bypass surgery in 7% (STEMI 5%, NSTEMI 11%, undetermined AMI 7%). The in-hospital and 30-day case fatality rates were 7.4% and 9.4%, respectively (7.5% and 9.5% for STEMI, 5.2% and 7.1% for NSTEMI, 18.2% and 21.2% for undetermined MI).
CONCLUSIONS: Patients with acute myocardial infarction admitted to the Italian CCUs, are older than those represented in clinical trials. A high proportion of these cases has the chance to receive early reperfusion therapy. Short-term mortality is lower than expected for patients with STEMI, but higher than reported for NSTEMI.