Prognostic significance of QRS fragmentation and correlation with infarct size in patients with anterior ST-segment elevation myocardial infarction treated with percutaneous coronary intervention: Insights from the INFUSE-AMI trial

Background QRS fragmentation (fQRS) is believed to reflect myocardial scar formation in patients with coronary disease. Whether early formation of fQRS in patients with ST-segment elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) is correlated with infarct size and prognosis is unknown. We assessed the prognostic value of fQRS at 60 min post-PCI and its correlation with infarct size in patients with anterior STEMI managed with primary PCI. Methods The INFUSE-AMI trial enrolled 452 patients with anterior STEMI undergoing primary PCI. Electrocardiograms (ECGs) were performed at baseline and 60 min post-PCI. Infarct size was evaluated using cardiac magnetic resonance imaging at 30 days post-PCI. Target vessel failure (TVF) was defined as the composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target vessel revascularization. Study groups were defined as patients with versus without fQRS at 60 min post-PCI. Results Out of 421 patients with ECG data 60 min post-PCI, 68 patients (16.2%) had fQRS. Patients with versus without fQRS had similar baseline characteristics and infarct size (16.9% ± 8.7% vs. 16.1% ± 10.5%, p = 0.62), but patients with fQRS had higher adjusted risk of 1-year TVF (adjusted HR 2.27, 95% CI 1.06–4.89, p = 0.036) and a trend toward a higher risk of the composite cardiac death or target vessel myocardial infarction (9.0% vs. 4.1%, p = 0.08) at 1 year. Conclusion fQRS in patients with STEMI is associated with TVF but does not correlate with infarct size.