Impact of the magnitude of the initial ST-segment elevation on left ventricular function in patients with anterior acute myocardial infarction.

BACKGROUND: In the percutaneous coronary intervention (PCI) era, the impact of initial ST-segment elevation magnitude on left ventricular (LV) function in patients with acute myocardial infarction (AMI) remains unclear. METHODS AND RESULTS: In the present study, 239 patients with total occlusion and 81 patients with spontaneous reperfusion within 12 h of their first anterior AMI were evaluated. The sum of ST-segment elevation (SigmaST) was measured in leads I, aV(L) and V(1-6) shortly before angiography. Predischarge LV ejection fraction (LVEF) was obtained at 15+/-5 days. In total occlusion, the predischarge LVEF was significantly lower in patients with SigmaST >/=10 mm than in those with SigmaST <10 mm (51+/-14% vs 57+/-14%, p<0.01). However, in spontaneous reperfusion, there was no significant difference between patients with ST >/=10 mm and those with SigmaST <10 mm (61+/-13 vs 62+/-14 %, p=NS). Predischarge LVEF significantly correlated with SigmaST in total occlusion (r=-0.25, p<0.01), but not in spontaneous reperfusion (r=0.03, p=NS). CONCLUSION: The results suggest that initial SigmaST is an important predictor of LV function in patients with total occlusion, but not in those with spontaneous reperfusion.