Regression of Q waves and clinical outcomes following primary PCI in anterior STEMI.

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 90 min following PCI, as well as at hospitalization discharge and 12 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€¯2784 IU/l vs. 3814 ±â€¯2595 IU/l vs. 1733 ±â€¯1583 IU/l respectively, p < 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 (p = 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]; p = 0.03), but there was no significant difference between NQ and RQ groups (HR 3.3 [0.8; 13.8]; p = 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.

Incidence and Significance of Spontaneous ST Segment Re-elevation After Reperfused Anterior Acute Myocardial Infarction　- Relationship With Infarct Size, Adverse Remodeling, and Events at 1 Year.

BACKGROUND: Up to 25% of patients with ST elevation myocardial infarction (STEMI) have ST segment re-elevation after initial regression post-reperfusion and there are few data regarding its prognostic significance.Methods and Results:A standard 12-lead electrocardiogram (ECG) was recorded in 662 patients with anterior STEMI referred for primary percutaneous coronary intervention (PPCI). ECGs were recorded 60-90 min after PPCI and at discharge. ST segment re-elevation was defined as a ≥0.1-mV increase in STMax between the post-PPCI and discharge ECGs. Infarct size (assessed as creatine kinase [CK] peak), echocardiography at baseline and follow-up, and all-cause death and heart failure events at 1 year were assessed. In all, 128 patients (19%) had ST segment re-elevation. There was no difference between patients with and without re-elevation in infarct size (CK peak [mean±SD] 4,231±2,656 vs. 3,993±2,819 IU/L; P=0.402), left ventricular (LV) ejection fraction (50.7±11.6% vs. 52.2±10.8%; P=0.186), LV adverse remodeling (20.1±38.9% vs. 18.3±30.9%; P=0.631), or all-cause mortality and heart failure events (22 [19.8%] vs. 106 [19.2%]; P=0.887) at 1 year. CONCLUSIONS: Among anterior STEMI patients treated by PPCI, ST segment re-elevation was present in 19% and was not associated with increased infarct size or major adverse events at 1 year.