ST-segment elevation and the Tpeak-Tend/QT ratio predict the occurrence of malignant arrhythmia events in patients with vasospastic angina.

BACKGROUND

ST-segment elevation (STE) and an increased Tpeak-Tend interval (Tp-e) have prognostic value for malignant arrhythmia events (MAEs) in patients with ST-segment elevation myocardial infarction (STEMI) and Brugada syndrome. Whether STE could predict MAEs and has an electrophysiological relationship with Tp-e in electrocardiogram (ECG) of vasospastic angina (VA) patients needs to be elucidated.

METHODS

Sixty-five patients with VA and 23 patients with VA complicated by MAEs were enrolled. The relationship of ECG parameters and MAEs (defined as ventricular tachycardia/ventricular fibrillation (VT/VF), syncope, and aborted sudden death) was analyzed by t-test, regression and receiver operating characteristic (ROC) curve analyses.

RESULTS

Patients with MAEs showed greater STE (P<0.001) and corrected QT dispersion (cQTd) (P=0.021), a longer corrected Tp-e interval (cTp-e) (P<0.001), and a larger Tp-e/QT ratio (P<0.001) than those in non-MAE groups. Univariate analysis revealed that cQTd (odds ratio (OR)=1.065; P=0.020), cTp-e (OR=1.159; P=0.001), Tp-e/QT (OR=1.344, P=0.002), and STE (OR=5.655, P<0.001) were significantly associated with MAEs. In the multivariate analysis, Tp-e/QT and STE remained predictors of MAEs. ROC curve analysis showed that the areas under curve (AUCs) for Tp-e/QT (AUC=0.944) and STE (AUC=0.974) were not significantly different (P>0.05), but both were significantly different than AUCs for cQTd (AUC=0.724) and cTp-e (AUC=0.841) (all P<0.05). STE was well fitted with the Tp-e/QT ratio in a multivariable linear regression model.

CONCLUSIONS

STE and increased Tp-e/QT ratio had related electrophysiological properties and were independent prognostic indicators of MAEs in patients with VA.