Introduction:
The aim of this study is to estimate how much of the recent decrease in mortality among patients with myocardial infarction with ST-segment elevation (STEMI) can be attributed to improved treatment strategies, and how much it is related to changes in baseline clinical characteristics, and to compare these findings for men and women.

Material and methods:
This was a retrospective analysis of 32,790 patients with STEMI from the Polish Registry of Acute Coronary Syndromes PL-ACS hospitalised in 2005 and 2011. Changes in treatment strategies including pharmacotherapy were analysed. Observed in-hospital and 12-month mortality rates were compared with the outcomes in the groups matched on the propensity scores.

Results:
There was a substantial improvement in STEMI patient management between 2005 and 2011 in Poland. It included greater use of percutaneous coronary interventions and other guideline-based adjunctive therapies, and it was associated with a significant decline in in-hospital mortality. Relative 12-month mortality reduction rates were less pronounced and more related to changes in patients’ clinical characteristics. Higher mortality risk reductions were observed in women and were driven by relatively more positive changes in their baseline risk profiles when compared to men.

Conclusions:
The progress in the treatment strategies has helped to achieve better survival rates in STEMI patients. However, the ongoing changes in clinical characteristics of patients also played an important role, especially in women. Clinicians should focus on modifiable risk factors and post-discharge management to possibly prolong the positive aspects of in-hospital efforts.