Does Lack of ST-Segment Resolution Still Have Prognostic Value 6 Years After an Acute Myocardial Infarction Treated With Coronary Intervention?

Background: Limited data exist in regard to the correlation between ST-segment resolution (STR) in patients treated with primary percutaneous coronary intervention (pPCI) and very late mortality. The aim of the study was to determine the correlation between STR and 6-year mortality in patients successfully treated with pPCI. Methods: We prospectively studied a group of 303 patients who had sustained an acute myocardial infarction with ST-segment elevation and subsequently exhibited TIMI 3 flow after pPCI. The patients were analyzed in 2 groups according to STR. Results: There were 222 patients (73.3%) with STR and 81 patients (26.7%) without it. The mean "pain-to-balloon" time was 4.3 +/- 2.1 hours in the former group vs 4.9 +/- 2.8 hours in the latter (P = 0.016). In total, 64 people (21%) died during the 6-year follow-up period: 37 (17%) showed STR and 28 (35%) did not (P < 0.001). In multivariate analysis, STR, ejection fraction, and maximum creatine kinase and creatine kinase-MB levels were all associated with death. Anterior myocardial infarction, "pain-to-balloon" time, and ejection fraction were all further associated with lack of STR. Conclusions: Lack of early STR is associated with significantly higher mortality rates after successful pPCI during a 6-year follow-up period. Absence of an early STR appears to identify patients who are less likely to benefit from the early restoration of infarct-affected artery, possibly due to microvascular damage. STR therefore appears to be a powerful prognostic marker for the occurrence of an acute myocardial infarction 6 years later.