Background
Guidelines for treatment of patients with myocardial infarction (MI) have been regularly updated. In addition, a new definition for acute MI has been recently established. The aim of our study was to evaluate development of treatment and effects on patient outcome.

Methods
We prospectively collected data from MI patients who were treated in 22 hospitals in Berlin, Germany, during the years 1999 to 2004. In the study we consecutively included 6080 MI patients presenting with (STEMI, n=4314) and without persistent ST-segment elevation (NSTEMI, n=1766).

Results
STEMI and NSTEMI patients showed an increase over time in arterial hypertension, smoking, hypercholesterolaemia, history of congestive heart failure, and renal failure.
The application of acute percutaneous coronary intervention increased from 15.3% to 62.3% (p<0.001) for NSTEMI and from 24.7% to 71.8% (p<0.001) for STEMI patients.
Concomitant therapy with beta-blockers, ACE inhibitors, statins, GP IIb/IIIa, and aspirin increased in parallel in both groups.
The decrease in hospital mortality was more pronounced for NSTEMI (13.5% vs. 4.6%, p<0.001) than with STEMI patients (13.0% vs. 9.4%, p=0.005).

Conclusions
Adherence to guidelines has led to a higher level of hospital care for NSTEMI and STEMI patients. Hospital mortality decreased for both groups, with a greater impact on NSTEMI patients.