Ischemic ST-segment episodes during the initial 24 hours of ST elevation myocardial infarction predict prognosis at 1 and 5 years

Abstract 

Objectives

The aims of the study were to assess the prognostic value of recurrent ischemic episodes during the first 24 hours in ST elevation myocardial infarction (STEMI) treated with thrombolysis and to explore those episodes as a part of a low-risk prognostic feature.

Design

Two hundred twenty patients with STEMI treated with thrombolysis were monitored for 24 hours with continuous online vectorcardiography assessing ST vector changes to record recurrent ischemic events.

Results

Ischemic events measured as an increase in ST-change vector magnitude (STC-VM) more than 50 μV for at least 2 minutes during 4- to 24-hour predicted mortality in a 5-year follow-up based on a multivariable analysis (hazard ratio, 1.18/episode; confidence interval, 1.01-1.37). The more episodes there were, the worse the prognosis. A low-risk group with a 1-year mortality of 1.9% could be identified.

Conclusion

Continuous ST-segment monitoring during the first 24 hours of a myocardial infarction is a valuable tool for identifying high- and low-risk patients. The STC-VM events during 4 to 24 hours of the first day of a myocardial infarction predict mortality within 5 years.

Keywords: Myocardial infarction, STEMI, Vectorcardiography, Electrocardiography, Thrombolysis, Reperfusion, Recurrent ischemic episodes, ST segment, Prognosis, Survival, Myocardial ischemia