Incidence and Implications of Q Waves After Acute ST-Elevation Myocardial Infarction in the Percutaneous Coronary Intervention Era

Background: Immediate coronary reperfusion is the cornerstone of therapy for acute ST-elevation myocardial infarction (STEMI), aiming to limit myocardial damage. Traditionally, the development of pathological Q waves on the electrocardiogram (ECG) has been considered a marker of irreversible transmural myocardial injury. However, most data on the incidence of pathological Q waves originate from the thrombolytic era. Therefore, the incidence and clinical significance of pathological Q waves in patients undergoing percutaneous coronary intervention (PCI) within the currently recommended time window remain unclear, as does the overall relationship with clinical outcomes. Methods: This study included 116 patients with STEMI who underwent PCI. In accordance with the current European Society of Cardiology guidelines, treatment was initiated within the recommended 90 minutes after admission. Results: Pathological Q waves developed in approximately 14% of patients, a lower incidence than that reported in the thrombolytic era. Pathological Q waves were more frequent among older patients, those with a lower baseline left ventricular ejection fraction (LVEF), and those with a longer time interval between admission and PCI. After adjustment for multiple variables, the presence of new pathological Q waves was not associated with an increased rate of one-year readmissions. Conclusions: In patients with STEMI undergoing PCI within the recommended time window, the incidence of pathological Q waves is substantially lower than that reported in the thrombolytic era and does not appear to be associated with a higher risk for readmissions. Further larger studies are warranted to confirm these findings.