Angiographic and clinical characteristics associated with the development of Q-wave and non-Q-wave myocardial infarction in the thrombolysis in myocardial infarction (TIMI) 14 trial

Abstract

Background: In the absence of thrombolytic therapy, patients with non-Q-wave myocardial infarction (MI) have previously been shown to have lower long-term mortality rates than patients with Q-wave MI. The goal of our study was to examine the angiographic and clinical differences between non-Q-wave MI and Q-wave MI in patients with ST elevation MI (STEMI) in the era of thrombolytic and combination therapy of thrombolytics plus glycoprotein IIb/IIIa inhibitors.

Methods: Angiography was performed 90 minutes after thrombolytic administration in the Thrombolysis in Myocardial Infarction (TIMI) 14 trial. The development of a non-Q-wave MI was assessed on electrocardiogram performed at the time of hospital discharge. Angiographic findings were assessed at an angiographic core laboratory by blinded investigators.

Results: The qualifying episode of ST elevation developed into a non-Q-wave MI in 36% of patients (315/878) and into a Q-wave MI in 64% of patients (563/878). In patients in whom non-Q-wave MI developed, the rate of TIMI grade 3 flow was higher, peak creatine kinase level was lower, mean left ventricular ejection fraction was greater, corrected TIMI frame counts (CTFCs) were lower (ie, faster blood flow), and chest pain duration after thrombolytic administration was shorter. Patients in whom non-Q-wave MI developed less frequently underwent a percutaneous coronary intervention (PCI), and when they did, they had faster post-PCI CTFCs and higher rates of post-PCI TIMI grade 3 flow. Patients in whom a non-Q-wave MI developed had lower rates of severe recurrent ischemia. There were no differences in 30-day or in-hospital mortality rates or recurrent MI between patients with Q-wave MI and patients with non-Q-wave MI.

Conclusion: After thrombolytic therapy in STEMI with or without abciximab, ejection fractions were higher, the duration of ischemia was shorter, and coronary blood flow at both 90 minutes and after PCI was faster in patients who sustained non-Q-wave MI than in patients who sustained Q-wave MI. No differences in mortality or recurrent MI rates were detected in patients who sustained a Q-wave MI and patients in whom a Q-wave MI did not evolve in the modern thrombolytic era.