Electrocardiogram score for the selection of reperfusion strategy in early latecomers with ST-segment elevation myocardial infarction.

Objective: The clinical benefit of percutaneous coronary intervention (PCI) is controversial in ST-segment elevation myocardial infarction (STEMI) patients presenting 12-72 hours after symptom onset. Several studies suggested this conflicting result was associated with myocardial area at risk (MaR) of enrolled patients. MaR could be estimated by the electrocardiogram (ECG) score. Our objective was to evaluate the benefits of PCI in STEMI latecomers with different MaR.

Methods: We constructed a prospective cohort involving 436 patients presenting 12-72 hours after STEMI onset and who met an inclusion criteria. 218 underwent PCI and 218 received the optimal medical therapy (OMT) alone. Individual MaR was quantified by the combined Aldrich ST and Selvester QRS score. The primary endpoint was a composite of cardiovascular death, reinfarction or revascularization within two years.

Results: The 2-year cumulative primary endpoint rate was respectively 9.2% in PCI group and 5.3% in OMT group when MaR<35% (adjusted hazard ratio for PCI vs. OMT, 1.855; 95% confidence interval [CI], 0.617-5.575; P=0.271), and was 12.8% in PCI group and 23.1% in OMT group when MaR ≥35% (adjusted hazard ratio for PCI vs. OMT, 0.448; 95% CI, 0.228-0.884; P=0.021).

Conclusion: The benefit of PCI for the STEMI latecomers was associated with the MaR. PCI, compared with OMT, could significantly reduce the 2-year primary outcomes in patients with MaR≥35%, but not in ones with MaR<35%.