Role of ST‐Segment Resolution Alone and in Combination With TIMI Flow After Primary Percutaneous Coronary Intervention for ST‐Segment–Elevation Myocardial Infarction

Background To evaluate the role of ST-segment resolution (STR) alone and in combination with Thrombolysis in Myocardial Infarction (TIMI) flow in reperfusion evaluation after primary percutaneous coronary intervention (PPCI) for ST-segment-elevation myocardial infarction by investigating the long-term prognostic impact. Methods and Results From January 2013 through September 2014, we studied 5966 patients with ST-segment-elevation myocardial infarction enrolled in the CAMI (China Acute Myocardial Infarction) registry with available data of STR evaluated at 120 minutes after PPCI. Successful STR included STR ≥50% and complete STR (ST-segment back to the equipotential line). After PPCI, the TIMI flow was assessed. The primary outcome was 2-year all-cause mortality. STR < 50%, STR ≥50%, and complete STR occurred in 20.6%, 64.3%, and 15.1% of patients, respectively. By multivariable analysis, STR ≥50% (5.6%; adjusted hazard ratio [HR], 0.45 [95% CI, 0.36-0.56]) and complete STR (5.1%; adjusted HR, 0.48 [95% CI, 0.34-0.67]) were significantly associated with lower 2-year mortality than STR <50% (11.7%). Successful STR was an independent predictor of 2-year mortality across the spectrum of clinical variables. After combining TIMI flow with STR, different 2-year mortality was observed in subgroups, with the lowest in successful STR and TIMI 3 flow, intermediate when either of these measures was reduced, and highest when both were abnormal. Conclusions Post-PPCI STR is a robust long-term prognosticator for ST-segment-elevation myocardial infarction, whereas the integrated analysis of STR plus TIMI flow yields incremental prognostic information beyond either measure alone, supporting it as a convenient and reliable surrogate end point for defining successful PPCI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01874691.