The electrocardiographic reperfusion peak in patients with ST-elevation myocardial infarction

ST peak during percutaneous coronary intervention serves as an early prognostic predictor in patients with ST-segment elevation myocardial

AIMS

To evaluate the clinical importance of the ST peak phenomenon during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

Continuous ST monitoring was performed in 942 STEMI patients from arrival until 90 minutes after revascularisation. ST peak was defined as ≥1 mm increase in the ST-segment during PCI compared with the ST elevation before intervention. ST peak was observed in 26.9% of patients. During median follow-up of 4.1 years, 20.7% of patients experienced a major adverse cardiac event (MACE). ST peak was associated with higher rates of mortality (13.4% versus 9.3%; p=0.044), admission for heart failure (10.6% versus 5.2%; p=0.002) and MACE (26.9% versus 18.2%; p=0.002), but not reinfarction (7.1% versus 5.2%; p=0.14). In two different Cox regression analyses, adjusting for predictors of MACE and ST peak including ST resolution and epicardial flow, ST peak remained significantly associated with MACE: adjusted hazard ratio (HR) 1.40 (95% confidence interval [CI] 1.01-1.95) and 1.41 (95% CI: 1.02-1.96).

CONCLUSIONS

In the largest study hitherto evaluating the ST peak phenomenon during primary PCI, we demonstrated that ST peak is a strong predictor of adverse long-term outcome and provides independent prognostic information beyond that provided by ST resolution and epicardial flow.

ST peak during primary percutaneous coronary intervention predicts final infarct size, left ventricular function, and clinical outcome

BACKGROUND AND PURPOSE

One third of patients treated with primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction develop a secondary increase in electrocardiographic ST segment (ST peak) during reperfusion. The purpose was to determine the clinical importance of ST peak during primary PCI.

METHODS

A total of 363 patients with ST-elevation myocardial infarction were stratified to no ST peak or ST peak. Final infarct size and ejection fraction (EF) were assessed by cardiovascular magnetic resonance.

RESULTS

Patients with ST peak had a larger infarct size (14% vs 10%; P = .003) and lower EF (53% vs 57%; P = .022). Rates of cardiac mortality (8% vs 3%; P = .047) and cardiac events (cardiac mortality and admission for heart failure; 19% vs 10%; P = .018) were higher among patients with ST peak, but not all-cause mortality (8% vs 5%; P = .46). In a multivariable Cox regression analysis, ST peak remained significantly associated with cardiac events (adjusted hazard ratio, 2.03 [1.08-3.82]).

CONCLUSION

ST peak during primary PCI is related to larger final infarct size, a reduced EF, and adverse cardiac clinical outcome.