Predictive value of electrocardiographic QT interval and T-wave morphology parameters for all-cause and cardiovascular mortality in a general population sample.
BACKGROUND
The predictive value of ECG QT interval for mortality in the general population has been weak. Only a few population studies on the predictive value of ECG T-wave morphology parameters for mortality have been reported.


OBJECTIVE
The purpose of this study was to examine the predictive value of ECG QT interval and T-wave morphology parameters for all-cause and cardiovascular mortality in the general population.


METHODS
The prognostic values of ECG QT interval and four T-wave morphology parameters (principal component analysis ratio, T-wave morphology dispersion, total cosine R-to-T, T-wave residuum) were assessed in 5,917 adults (45% men; age 52 +/- 14 years) participating in the Finnish population-based Health 2000 Study.


RESULTS
After a mean follow-up of 5.9 +/- 0.8 years, 335 deaths had occurred, including 131 cardiovascular deaths. QT interval and, with a few exceptions, all T-wave morphology parameters were significant univariate mortality predictors. In men, in Cox multivariate analyses, principal component analysis ratio and T-wave morphology dispersion remained as independent predictors of all-cause and cardiovascular mortality, with the above-median T-wave morphology dispersion group showing the highest risk of cardiovascular death (hazard ratio [HR] 4.4, 95% confidence interval [CI] 2.1-9.4). In women, independent mortality predictors were total cosine R-to-T (cardiovascular mortality) and T-wave residuum (all-cause and cardiovascular mortality), with the above-median T-wave residuum group showing the highest risk of cardiovascular death (HR 2.2, 95% CI 1.1-4.2).


CONCLUSIONS
In the general population, T-wave morphology parameters, but not heart rate-corrected QT interval, provide independent prognostic information on mortality. The prognostic value of T-wave morphology parameters is specifically related to cardiovascular mortality and seems to be gender specific.
Porthan
Kimmo
K
Department of Cardiology, Helsinki University Central Hospital, Helsinki, Finland. porthan@mappi.helsinki.fi
Viitasalo
Matti
M
Jula
Antti
A
Reunanen
Antti
A
Rapola
Janne
J
Väänänen
Heikki
H
Nieminen
Markku S
MS
Toivonen
Lauri
L
Salomaa
Veikko
V
Oikarinen
Lasse
L
D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology; D016001:Confidence Intervals; D004562:Electrocardiography / Q000295:instrumentation*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008133:Long QT Syndrome / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires