The terminal part of the QT interval (T peak to T end): a predictor of mortality after acute myocardial infarction.

Abstract

BACKGROUND:

The terminal part of the QT interval (T peak to T end; Tp-e)-an index for dispersion of cardiac repolarization-is often prolonged in patients experiencing malignant ventricular arrhythmias after acute myocardial infarction (AMI). We wanted to explore whether high Tp-e might predict mortality or fatal arrhythmia post-AMI.

METHODS:

Tp-e was measured prospectively in 1359/1384 (98.2%) consecutive patients with ST elevation (n = 525) or non-ST elevation (n = 859) myocardial infarction (STEMI or NSTEMI) admitted for coronary angiography.

RESULTS:

Tp-e was significantly correlated with age, heart rate (HR), heart failure, LVEF, creatinine, three-vessel disease, previous AMI and QRS and QT duration. During a mean follow-up of 1.3 years (range 0.4-2.3),109 patients (7.9%) died; 25, 45, and 39 from cardiac arrhythmia, nonarrhythmic cardiac causes and other causes, respectively. Long Tp-e was strongly associated with increased risk of death, and Tp-e remained a significant predictor of death in multivariable Cox analyses (RR 1.5, 95% CI[1.3-1.7]). HR-corrected Tp-e (cTp-e) was the strongest predictor of death (RR 1.6 [1.4-1.9]). Tp-e and cTp-e were particularly strong predictors of fatal cardiac arrhythmia (RR 1.6 [1.2-2.1] and RR 1.8 [1.4-2.4]). Findings were similar in STEMI and NSTEMI. When comparing two methods for measuring Tp-e, one including the tail of the T wave and one not, the former had markedly higher predictive power (P < 0.001).

CONCLUSION:

Tp-e, and in particular cTp-e, were strong predictors of mortality during the first year post-AMI, and should be further evaluated as prognostic factors additional to established post-AMI risk factors.

• Authors: Gunnar Erikssen, Knut Liestøl, Lars Gullestad, Kristina H Haugaa, Bjørn Bendz, Jan P Amlie
• Journal: Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc (Ann Noninvasive Electrocardiol) Vol. 17 Issue 2 Pg. 85-94 (Apr 2012) ISSN: 1542-474X [Electronic] United States
• PMID: 22537325 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012, Wiley Periodicals, Inc.

Chemical References

• Biomarkers
• Creatinine

Topics

• Adult
• Age Factors
• Aged
• Aged, 80 and over
• Biomarkers (blood)
• Coronary Angiography
• Coronary Disease (physiopathology)
• Creatinine (blood)
• Electrocardiography
• Female
• Heart Conduction System (physiopathology)
• Heart Failure (physiopathology)
• Heart Rate (physiology)
• Humans
• Male
• Middle Aged
• Myocardial Infarction (complications, mortality, physiopathology)
• Norway (epidemiology)
• Predictive Value of Tests
• Proportional Hazards Models
• Prospective Studies
• ROC Curve
• Risk Factors
• Survival Rate
• Tachycardia, Ventricular (physiopathology)