Impact of age on short- and long-term mortality of patients with ST-elevation myocardial infarction in the VIENNA STEMI network.

BACKGROUND AND AIM

Our senescent society includes a growing number of elderly people suffering from ST-elevation myocardial infarction (STEMI); however, exactly this population is often underrepresented in randomized trials. Hence, our aim was to investigate the influence of age on patient characteristics, as well as short- and long-term outcome in the Vienna STEMI registry.

METHODS

We included all patients of the Vienna STEMI registry (2003-2009). Patients were stratified into age cohorts (≤45, 46-59, 60-79 and ≥80 years, respectively). Differences between cohorts were investigated by descriptive statistics and regression models. Crude and adjusted mortality rates were investigated using log rank test and Cox regression models, respectively. The influence of treatment on mortality was further investigated using propensity score matching.

RESULTS

A total of 4579 patients fulfilled the criteria for further investigation. With rising age of cohorts, the number of females, diabetes mellitus (DM), hypertension (HTN), previous myocardial infarction (MI), shock, no reperfusion therapy and anterior wall infarction significantly increased. In contrast, the number of patients with a positive family history, smoking and hyperlipidemia (HLP) significantly declined. Log rank analysis showed significant differences between age cohorts for short- and long-term mortality. Cox regression analysis for short-term mortality revealed an independent association for age at the event, HTN and shock, while age, smoking, DM, HTN, HLP, previous MI and shock independently influenced long-term mortality after correction for confounders. Also, we found a significant association of age and total ischemic time (TIT), which however had no influence on long-term mortality (interaction term p = 0.236). Propensity score matching revealed reduced mortality rates for patients who received reperfusion therapy compared to conservative management, irrespective of age.

CONCLUSIONS

Increasing age independently influenced short- and long-term mortality in patients with STEMI in the Vienna STEMI network. The TIT significantly increased with baseline age, but had no impact on mortality. Furthermore, reperfusion therapy exerted beneficial effects irrespective of the patients' age.