Original-clinicalGeneralPredictive value of electrocardiographic QT interval and T-wave morphology parameters for all-cause and cardiovascular mortality in a general population sample
Introduction
In patients with cardiovascular disease, abnormalities of ventricular repolarization on the electrocardiogram (ECG) are associated with cardiac morbidity and mortality; however, in the general population, the predictive value of heart rate-corrected QT interval for mortality has been weak.1, 2, 3, 4, 5 In recent years, computer-based analysis of digital ECG has produced new measures of ventricular repolarization, characterizing the three-dimensional morphology of the T wave.6, 7 These T-wave morphology parameters have been shown to provide prognostic information on survival in patients with cardiovascular disease as well as in patients with diabetes mellitus or end-stage renal disease.8, 9, 10, 11, 12, 13 Some evidence indicates that T-wave morphology parameters may contain prognostic information on mortality risk in the general population as well.7, 14, 15
The aim of this study was to explore the predictive value of T-wave morphology parameters for all-cause and cardiovascular mortality in the general population. The prespecified substudy of the Health 2000 Study provided high-quality digital ECGs and detailed clinical data from a large general population sample.16 We assessed ventricular repolarization using a set of four T-wave morphology parameters: principal component analysis ratio (PCA ratio, an estimate of T-wave complexity); T-wave morphology dispersion (TMD, an estimate of deviation between T waves); total cosine R-to-T (TCRT, an estimate of deviation between R and T waves); and T-wave residuum (TWR, an estimate of repolarization heterogeneity). We hypothesized that T-wave morphology parameters may provide independent prognostic information on all-cause and cardiovascular mortality in a large general population sample.
Section snippets
Study population and disease classification
The study population was derived from the Health 2000 Study, an epidemiologic survey that was conducted in Finland between fall 2000 and spring 2001. The study population, drawn from the Finnish Population Information System, was a two-stage stratified cluster sample of 8,028 Finnish adults aged ≥30 years. The Health 2000 Study consisted of a home interview, a comprehensive health examination including questionnaires, measurements (e.g., height, weight, blood pressure [BP], ECG), and a
Clinical data
Clinical characteristics of the study population are given in Table 1. Mean follow-up was 71 ± 9 months (5.9 ± 0.8 years). Of the 5,917 study subjects, 335 (5.7%) died during follow-up (9.6 deaths per 1,000 person-years of follow-up). Of all 335 deaths, 131 (39%) were cardiovascular deaths. In men, significant clinical predictors of all-cause and cardiovascular mortality were age, current smoking (all-cause mortality only), systolic BP, diastolic BP (all-cause mortality only), hypertension,
Main findings
In a large, population-based prospective study, ECG T-wave morphology parameters, but not heart rate-corrected QT interval, provide independent prognostic information specifically on cardiovascular mortality. T-wave morphology parameters show gender specificity in their performance, with PCA ratio and TMD in men as well as TWR in women providing the highest prognostic value.
QT interval as a mortality predictor in the general population
The T wave on the surface ECG is generated by myocardial voltage gradients during ventricular repolarization.24 Time from
Conclusion
In the general population, rate-adjusted QT interval and T-wave morphology parameters have predictive value for all-cause and cardiovascular mortality. However, when other risk factors of mortality are taken into account, T-wave morphology parameters, but not rate-adjusted QT interval, provide independent and thus potentially clinically useful risk assessment data for the general population. The independent prognostic value of these parameters is specifically related to cardiovascular mortality
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Electrocardiographic T-wave morphology and risk of mortality
2021, International Journal of CardiologyParameters of repolarization heterogeneity are associated with myocardial recovery in acute heart failure
2020, International Journal of CardiologyCitation Excerpt :These parameters include QRST angle, T peak to T end interval, JT interval, QT dispersion, and others [16]. Increased repolarization heterogeneity on ECG is associated with adverse cardiovascular and overall outcomes even in healthy community dwelling adult populations [7,8]. Markers of repolarization heterogeneity are also known to be associated with adverse outcomes in numerous cardiovascular populations, including hypertrophic cardiomyopathy, post myocardial infarction populations, and valvular heart disease, largely through their association with increased risk of ventricular arrhythmias [9–11].
ECG left ventricular hypertrophy as a risk predictor of sudden cardiac death
2019, International Journal of CardiologyComparison of automated interval measurements by widely used algorithms in digital electrocardiographs
2018, American Heart JournalVentricular repolarization alterations in women with angina pectoris and suspected coronary microvascular dysfunction
2018, Journal of ElectrocardiologyTracking interlead heterogeneity of R- and T-wave morphology to disclose latent risk for sudden cardiac death
2017, Heart RhythmCitation Excerpt :This problem has been attributed to difficulties similar to those with QT dispersion with respect to reproducibility and accuracy due to irregularities in the apex of the T wave and its termination. Given the limitations of interval-based measurements, considerable interest has arisen about whether assessing the entire morphology of the T wave might be a more precise and sound approach for quantifying nonuniformities in repolarization.20,23–26 The inherent advantage of considering morphology-based assessment is evident in superimposition of precordial leads in Figure 3 (right panel).
This work was supported by grants to Dr. Porthan from the Aarne Koskelo Foundation, the Finnish Foundation for Cardiovascular Research, the Ida Montin Foundation, the Orion-Farmos Research Foundation, and the Paavo and Eila Salonen Foundation.