Intracoronary electrocardiogram ST-segment elevation in patients with non-ST-segment elevation myocardial infarction and its association with culprit lesion location and myocardial injury

AIMS: An intracoronary electrocardiogram (IC-ECG) is a sensitive method to detect local myocardial ischaemia. We investigated the prevalence of IC-ECG ST-segment elevation (STE) with respect to culprit lesion location in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and its relationship with elevated levels of cardiac biomarkers. METHODS AND RESULTS: We examined 87 NSTEMI patients who underwent IC-ECG recording by locating the insulated polymer-coated guidewire distal to the culprit lesion before percutaneous coronary intervention (PCI). Cardiac biomarkers were serially examined. IC-ECG STE was observed in 24 patients (27.6%) before PCI, and was significantly more frequent in patients with LCx culprit lesions (LAD vs. LCx vs. RCA, 12.1% vs. 53.3% vs. 16.7%; p<0.001). Peak cardiac troponin I (cTnI) values were associated with IC-ECG STE, ejection fraction (EF), cTnI values on admission, and type B2/C lesions. In multivariate analysis, IC-ECG STE (odds ratio [OR], 5.04; 95% confidence intervals [CI]: 1.51-16.85; p=0.009), and EF (OR, 0.95; 95% CI: 0.90-1.00; p=0.043) were predictors of greater peak cTnI values. CONCLUSIONS: IC-ECG STE was not uncommon in NSTEMI patients, particularly those with LCx culprit lesions. IC-ECG monitoring before PCI may help identify NSTEMI patients with high risk of greater myocardial injury.