Elsevier

Journal of Electrocardiology

Volume 42, Issue 6, November–December 2009, Pages 555-560
Journal of Electrocardiology

The prognostic value of the Tpeak-Tend interval in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

https://doi.org/10.1016/j.jelectrocard.2009.06.009Get rights and content

Abstract

Introduction

The Tpeak-Tend interval (TpTe) has been linked to increased arrhythmic risk. TpTe was investigated before and after primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation myocardial infarction (STEMI).

Method

Patients with first-time STEMI treated with pPCI were included (n = 101; mean age 62 years; range 39-89 years; 74% men). Digital electrocardiograms were taken pre- and post-PCI, respectively. Tpeak-Tend interval was measured in leads with limited ST-segment deviation. The primary end point was all-cause mortality during 22 ± 7 months (mean ± SD) of follow-up.

Results

Pre- and post-PCI TpTe were 104 milliseconds [98-109 milliseconds] and 106 milliseconds [99-112 milliseconds], respectively (mean [95% confidence interval], P = .59). A prolonged pre-PCI TpTe was associated with increased mortality (hazard ratio, 10.5 [1.7-20.4] for a cutoff value of 100 milliseconds). Uncorrected QT and heart rate–corrected QT intervals (Fridericia-corrected QT) were prolonged after PCI (QT: 401 vs 410 milliseconds, P = .022, and Fridericia-corrected QT: 430 vs 448 milliseconds, P < .0001).

Conclusion

In patients with STEMI undergoing pPCI, pre-PCI TpTe predicted subsequent all-cause mortality, and the QT interval was increased after the procedure.

Introduction

Myocardial infarction (MI) is a major cause of morbidity and mortality. Electrophysiological characterization of arrhythmogenic substrates in the myocardium of post-MI patients has shown clinical promise for prediction of malignant arrhythmias. Among these variables and measurements are a prolonged QT interval, signal-averaged electrocardiogram (ECG), and T wave alternans, but they all have drawback of not being useful in the acute clinical setting because their prognostic value is first manifested when measured 6 to 8 weeks post-MI.1, 2, 3, 4, 5

The interval from the peak to the end of the T wave (Tpeak-Tend interval, or TpTe) has been proposed to represent repolarization dispersion in the heart. However, to what extent TpTe expresses transmural apicobasal, left-to-right ventricle, or anterior-posterior electrical gradients influence is not clear.6, 7 A prolonged TpTe has been associated with arrhythmic events in various clinical conditions,2,8, 9, 10, 11, 12, 13 but little is known about TpTe in the acute setting of transmural myocardial ischemia and reperfusion, for example, in patients with ST-segment elevation MI (STEMI) undergoing primary percutaneous coronary intervention (pPCI). The purpose of the present study was to evaluate TpTe immediately before and after pPCI in patients with STEMI and evaluate its prognostic value.

Section snippets

Study subjects

Patients were recruited from a single tertiary catheterization laboratory of a high PCI volume center (Gentofte University Hospital, Copenhagen, Denmark: 650 pPCI and 1200 elective PCI per year performed by 5 PCI operators). Patients were included if they had (1) relevant chest discomfort, (2) ECG changes fulfilling the criteria for STEMI, (3) pPCI, and (4) a significant stenosis or occlusion requiring placement of at least 1 intracoronary stent. After pPCI, patients received usual standard of

Demographics and follow-up

Demographic, clinical, and angiographic data are summarized in Table 1. No patients were lost to follow-up. There were 10 deaths in the population, with a mean (SD) follow-up time of 683 (211) days.

TpTe and survival

The pre-pPCI TpTe was prolonged in patients that died during follow-up. However, the post-pPCI TpTe was similar between surviving and deceased patients (Table 2). Using the Youden index, the optimal cutoff point was determined to be 100 milliseconds for the pre-pPCI TpTe, with a sensitivity and

Discussion

The main findings of this study of patients with STEMI undergoing pPCI were: (1) the pre-pPCI TpTe predict all-cause mortality; (2) TpTe was not associated with infarct-related artery, LVEF, or symptom to balloon time; and (3) QT interval was prolonged after pPCI.

Conclusion

In conclusion, TpTe pre-pPCI predicted all-cause mortality in patients with STEMI undergoing pPCI. TpTe and the QT interval were increased after pPCI, whereas TpTe seems to be independent of infarct-related artery, LVEF, and symptom to balloon time. Pre-pPCI may be a new marker of increased risk in patients with STEMI undergoing pPCI, and the clinical value of this parameter should be further evaluated.

References (34)

  • KantersJ.K. et al.

    T-peak to T-end (TpTe) interval in long QT syndrome

    J Electrocardiol

    (2008)
  • De LucaG. et al.

    Symptom-onset-to-balloon time and mortality in patients with acute myocardial infarction treated by primary angioplasty

    J Am Coll Cardiol

    (2003)
  • KuriachanV. et al.

    Role of risk stratification after myocardial infarction

    Curr Treat Options Cardiovasc Med

    (2009)
  • HuikuriH.V. et al.

    Prediction of fatal or near-fatal cardiac arrhythmia events in patients with depressed left ventricular function after an acute myocardial infarction

    Eur Heart J

    (2009)
  • TaggartP. et al.

    Transmural repolarisation in the left ventricle in humans during normoxia and ischaemia

    Cardiovasc Res

    (2001)
  • OpthofT. et al.

    Is there a significant transmural gradient in repolarization time in the intact heart? Repolarization gradients in the intact heart

    Circ Arrhythmia Electrophysiol

    (2009)
  • AntzelevitchC.

    Tpeak-Tend interval as an index of transmural dispersion of repolarization

    Eur J Clin Invest

    (2001)
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    The study was supported by the Danish Heart Foundation, John and Tove Girotti's Foundation, Danish National Research Foundation, King Christian X' Foundation and Lægernes Forsikringsforening.

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