Abstract 6179: Baseline Q Trumps Time from Symptom Onset as a Prognostic Marker in STEMI Patients Treated with Primary PCI
Current ST Elevation AMI guidelines and quality improvement initiatives emphasize that time from symptom onset to reperfusion is a critical factor in selection of reperfusion method and patient outcome. In fibrinolytic-treated patients, the presence of baseline Q-waves may signal later MI presentation and worse outcome. Whether these relationships hold with primary PCI is unclear. We tested this hypothesis in 5,186 analyzable STEMI patients (presenting <6 hours after symptom onset) undergoing primary PCI in APEX-AMI. Ninety-day mortality and death/CHF/shock adjusted for baseline factors (age, SBP, HR, Killip class, infarct site, extent of baseline ST deviation, symptom onset to randomization and Q-wave on the admission ECG). A majority of patients (56.4%) had Q-waves on admission. The table⇓ shows key baseline characteristics and 90-day outcomes according to presence of Q waves in the presenting STEMI and by time from sx onset to randomization. Multivariable adjustment of 90-day mortality (HR 1.89, 95%CI (1.36 –2.62), p<0.001) and composite outcomes HR 1.88(1.51–2.35), p<0.001 revealed that baseline Q but not time had prognostic value. These data argue strongly for considering baseline Q as an independent marker of the evolutionary state of myocardial infarction and a potentially useful tool in evaluating needed future therapeutic options for STEMI patients undergoing PCI.