[Rapid resolution of ST segment elevation predicts recovery of left myocardial contraction in patients with acute myocardial infarction treated with percutaneous coronary angioplasty].

BACKGROUND: Early epicardial vessel patency and tissue perfusion limit infarct size, improve survival and are crucial for optimum functional recovery of the ischaemic myocardium in patients with acute myocardial infarction (AMI). Coronary angiography has been considered the "gold standard" in assessment of reperfusion. Restoration of coronary patency is not a guarantee of myocardial cellular perfusion. ST-segment elevation resolution observed in electrocardiogram (ECG) early after initiation of primary PTCA could be potentially correlated with reperfusion.

AIM: The aim of the study was the prospective assessment of left ventricular (LV) contractility recovery in patients after primary PTCA for AMI in 3 and 6 month follow-up according to early ST-segment elevation resolution analysis.

METHODS: 111 consecutive patients (80 men and 31 women age 36-78) with AMI treated by successful primary PTCA (Thrombolysis in Myocardial Infarction grade 3 flow and residual stenosis less than 30%) within 12 h of chest pain onset were enrolled in the study. 12-lead ECG was performed on admission and 1 hour after the beginning of the PTCA. The patients were divided into 2 groups according to ST-segment elevation resolution in the ECG (> 50% depression of the elevated ST-segment) within 1 hour after the procedure. The mean pain-to-balloon time was not significantly different in both groups. In each patient, global ejection fraction (EF) and wall motion index (WMI) were derived immediately after primary PTCA and after 3 and 6 month follow-up.

RESULTS: Of the 111 patients studied, 82 (68%) had early ST-segment resolution and 29 (32%) did not. Contractility disturbances of infarct related ventricular wall, evaluated by EF and WMI, were significantly higher in the group of patients without early ST-segment resolution immediately after primary PTCA. EF and WMI improved significantly after 3 and 6 months in the group of patients with improvement was insignificant ST-segment elevation resolution, while in the group without ST-segment resolution.

CONCLUSIONS: 1. Presence of early ST segment elevation resolution after angiographically successful primary PTCA identifies patients who are more likely to benefit from the early restoration of flow in the infarct related artery. 2. TIMI measures greatly overestimate the success of primary PTCA; they only assess vessel patency, not myocardial cellular perfusion. 3. "Electrocardiographic reperfusion" provides a real-time physiologic marker of cellular perfusion and is a significant predictor of LV contractility recovery--more useful than angiographic reperfusion. 4. ST-segment monitoring is a reliable, non-invasive and inexpensive method to evaluate myocardial perfusion.