RESUMO
BACKGROUND: Pathological Q waves are correlated with infarct size, and Q-wave regression is associated with left ventricular ejection fraction improvement. There are limited data regarding the association of Q-wave regression and clinical outcomes. Our main objective was to assess the association of pathological Q wave evolution after reperfusion with clinical outcomes after anterior STEMI. METHODS: Standard 12-lead electrocardiograms (ECGs) were recorded in 780 anterior STEMI patients treated with primary percutaneous coronary intervention (PCI) from the CIRCUS trial. ECGs were recorded before and 90â¯min following PCI, as well as at hospitalization discharge and 12â¯months of follow-up. The number of classic ECG criteria Q waves was scored for each ECG. Patients were classified in the Q wave regression group if they had regression of at least one Q wave between the post-PCI, the discharge and/or one year ECGs. Patients were classified in the Q wave persistent group if they had the same number or greater between the post-PCI, the discharge and/or 1 and one year ECGs. All-cause death and heart failure events were assessed for all patients at one year. RESULTS: There were 323(43%) patients with persistent Q waves (PQ group), 378(49%) patients with Q wave regression (RQ group) and 60(8%) patients with non-Q wave MI (NQ group). Infarct size as measured by the peak creatine kinase was significantly greater in the PQ group compared to the RQ and NQ groups (4633⯱â¯2784â¯IU/l vs. 3814⯱â¯2595â¯IU/l vs. 1733⯱â¯1583â¯IU/l respectively, pâ¯<â¯0.0001). At one year, there were 22 deaths (7%) in the PQ-group, 15 (4%) in the RQ-group and none in the NQ-group (pâ¯=â¯0.04). There was a 4-fold increase in the risk of death or heart failure in the PQ compared to the NQ group (HR 4.7 [1.1; 19.3]; pâ¯=â¯0.03), but there was no significant difference between NQ and RQ groups (HR 3.3 [0.8; 13.8]; pâ¯=â¯0.09). CONCLUSION: In a population of anterior STEMI patients, persistent Q waves defined according to the classic ECG criteria after reperfusion was associated with a 4-fold increase in the risk of heart failure or death compared to non-Q-wave MI, while Q-wave regression was associated with significantly lower risk of events.