Resolution of ST-segment depression: A new prognostic marker in ST-segment elevation myocardial infarction

To evaluate the prognostic impact of ST depression resolution among patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI in the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) trial.

In this study, 4729 of 5745 patients had analysable ECGs demonstrating concomitant ST-segment depression. Resolution of summation operatorST elevation (STE-R) and summation operatorST depression (STD-R) on 30 min post-PCI ECGs was dichotomized into those with > or =50 vs. <50% ST-segment resolution. Overall, 1143 patients (24%) had STD-R<50%. These patients had higher risk characteristics including older age, female sex, diabetes, hypertension, prior CHF/MI, Killip class >I, triple vessel disease, and less frequent TIMI 3 flow in the culprit coronary vessel post-PCI. After multivariable adjustment and accounting for STE-R, STD-R<50% remained an independent predictor for 90 day death and the composite of death, cardiogenic shock, or CHF. When compared with patients with both STE-R and STD-R> or =50%, patients with both STE-R and STD-R<50% had the worst outcomes [hazard ratios (HR) 90 day death: 2.54; 95% confidence intervals (CI): 1.71-3.77; HR 90 day composite: 2.18; 95% CI: 1.63-2.91].

When ST depression is present in STEMI patients undergoing primary PCI, STD-R<50% provides independent prognostic value that is incremental to STE-R.