One-year mortality in patients with acute ST-elevation myocardial infarction in the Vienna STEMI registry

Systems of care to treat acute ST-elevation myocardial infarction (STEMI) have been developed world wide in the past decade. Their effectiveness can only be proven by including and analyzing outcome data of consecutive patients in registries, which is not the case in the majority of STEMI networks. This study investigates 1-year mortality in STEMI patients in Vienna included over a 14 months time interval. The Vienna STEMI network is organized by a specific rotational system and offers both, primary percutaneous intervention (PPCI) and thrombolytic therapy (TT) as reperfusion strategies according to the recent guidelines.

At the time of investigation, the Vienna STEMI network consisted of the Viennese Ambulance Systems and five high-volume interventional cardiology departments. This network has been organized in order to increase the number of STEMI patients admitted for PPCI and to offer the fastest available reperfusion strategy, in the majority PPCI but in selected patients also TT (STEMI of short duration, mainly anterior wall MI and mainly patients younger than 75 years), followed by rescue PCI in non-responders and elective angiography with/without PCI in responders to TT during the index hospital stay.

One-year all-cause mortality rates in the Vienna STEMI network by use of the fastest available reperfusion strategy were 13.4% in patients who received reperfusion therapy after 2 h of symptom onset and 7.4% in patients treated within 2 h; (p = 0.017). Whereas PPCI and TT demonstrated a nonsignificant difference in 1-year mortality rates when initiated within 2 h of symptom onset (10.0% vs 5.7%; p = 0.59), PPCI was more effective in acute STEMI of > 2 h duration as compared to TT but this difference did not reach statistical significance (12.1% vs 18.2%; p = 0.07).

The reassuring long-term results of the Viennese STEMI network are another example of a specific regional system of care to offer timely diagnosis, transfer and reperfusion in patients with STEMI. In contrast to other metropolitan areas where TT has almost completely abandoned, we still use pharmacological reperfusion as a backup in case of expected and unacceptable time delays for PPCI in order to reduce myocardial damage especially in patients with larger infarctions of short duration with a low risk of bleeding complications.