The prognostic significance of single-lead ST-segment resolution in ST-segment elevation myocardial infarction patients treated with primary PCI: A substudy of the randomized TOTAL trial

BACKGROUND: ST-segment elevation myocardial infarction (STEMI) is associated with high morbidity and mortality worldwide. Simple electrocardiogram (ECG) tools, including ST-segment resolution (STR) have been developed to identify high-risk STEMI patients after primary percutaneous coronary intervention (PCI).

SUBJECTS AND METHODS: We evaluated the prognostic impact of STR in the ECG lead with maximal baseline ST-segment elevation (STE) 30-60 minutes after primary PCI in 7,654 STEMI patients included in the TOTAL trial. Incomplete or no STR was defined as < 70% STR and complete STR as ≥ 70% STR. The primary outcome was the composite of cardiovascular death, recurrent myocardial infarction (MI), cardiogenic shock, or new or worsening New York Heart Association (NYHA) class IV heart failure at 1-year follow-up.

RESULTS: Of 7,654 patients, 42.9% had incomplete or no STR and 57.1% had complete STR. The primary outcome occurred in 341 patients (10.4%) in the incomplete or no STR group and in 234 patients (5.4%) in the complete STR group. In Cox regression analysis, adjusted hazard ratio for STR < 70% to predict the primary outcome was 1.56 (95% confidence interval 1.32-1.89; P < .001) (model adjusted for all baseline comorbidities, clinical status during hospitalization, angiographic findings, and procedural techniques).

CONCLUSION: In a large international study of STEMI patients, STR < 70% 30-60 minutes post primary PCI in the ECG lead with the greatest STE at admission was associated with an increased rate of the composite of cardiovascular death, recurrent MI, cardiogenic shock, or new or worsening NYHA class IV heart failure at 1-year follow-up. Clinicians should pay attention to this simple ECG finding.