Risk prediction of cardiovascular death based on the QTc interval: evaluating age and gender differences in a large primary care population

TY - JOUR

T1 - Risk prediction of cardiovascular death based on the QTc interval

T2 - evaluating age and gender differences in a large primary care population

AU - Nielsen, Jonas B

AU - Graff, Claus

AU - Rasmussen, Peter V

AU - Pietersen, Adrian

AU - Lind, Bent

AU - Olesen, Morten S

AU - Struijk, Johannes J

AU - Haunsø, Stig

AU - Svendsen, Jesper H

AU - Køber, Lars

AU - Gerds, Thomas A

AU - Holst, Anders G

N1 - © The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.

PY - 2014/5/21

Y1 - 2014/5/21

N2 - AIMS: Using a large, contemporary primary care population we aimed to provide absolute long-term risks of cardiovascular death (CVD) based on the QTc interval and to test whether the QTc interval is of value in risk prediction of CVD on an individual level.METHODS AND RESULTS: Digital electrocardiograms from 173 529 primary care patients aged 50-90 years were collected during 2001-11. The Framingham formula was used for heart rate-correction of the QT interval. Data on medication, comorbidity, and outcomes were retrieved from administrative registries. During a median follow-up period of 6.1 years, 6647 persons died from cardiovascular causes. Long-term risks of CVD were estimated for subgroups defined by age, gender, cardiovascular disease, and QTc interval categories. In general, we observed an increased risk of CVD for both very short and long QTc intervals. Prolongation of the QTc interval resulted in the worst prognosis for men whereas in women, a very short QTc interval was equivalent in risk to a borderline prolonged QTc interval. The effect of the QTc interval on the absolute risk of CVD was most pronounced in the elderly and in those with cardiovascular disease whereas the effect was negligible for middle-aged women without cardiovascular disease. The most important improvement in prediction accuracy was noted for women aged 70-90 years. In this subgroup, a total of 9.5% were reclassified (7.2% more accurately vs. 2.3% more inaccurately) within clinically relevant 5-year risk groups when the QTc interval was added to a conventional risk model for CVD.CONCLUSION: Important differences were observed across subgroups when the absolute long-term risk of CVD was estimated based on QTc interval duration. The accuracy of the personalized CVD prognosis can be improved when the QTc interval is introduced to a conventional risk model for CVD.

AB - AIMS: Using a large, contemporary primary care population we aimed to provide absolute long-term risks of cardiovascular death (CVD) based on the QTc interval and to test whether the QTc interval is of value in risk prediction of CVD on an individual level.METHODS AND RESULTS: Digital electrocardiograms from 173 529 primary care patients aged 50-90 years were collected during 2001-11. The Framingham formula was used for heart rate-correction of the QT interval. Data on medication, comorbidity, and outcomes were retrieved from administrative registries. During a median follow-up period of 6.1 years, 6647 persons died from cardiovascular causes. Long-term risks of CVD were estimated for subgroups defined by age, gender, cardiovascular disease, and QTc interval categories. In general, we observed an increased risk of CVD for both very short and long QTc intervals. Prolongation of the QTc interval resulted in the worst prognosis for men whereas in women, a very short QTc interval was equivalent in risk to a borderline prolonged QTc interval. The effect of the QTc interval on the absolute risk of CVD was most pronounced in the elderly and in those with cardiovascular disease whereas the effect was negligible for middle-aged women without cardiovascular disease. The most important improvement in prediction accuracy was noted for women aged 70-90 years. In this subgroup, a total of 9.5% were reclassified (7.2% more accurately vs. 2.3% more inaccurately) within clinically relevant 5-year risk groups when the QTc interval was added to a conventional risk model for CVD.CONCLUSION: Important differences were observed across subgroups when the absolute long-term risk of CVD was estimated based on QTc interval duration. The accuracy of the personalized CVD prognosis can be improved when the QTc interval is introduced to a conventional risk model for CVD.

KW - Age Factors

KW - Aged

KW - Aged, 80 and over

KW - Cardiovascular Diseases

KW - Electrocardiography

KW - Female

KW - Heart Rate

KW - Humans

KW - Male

KW - Middle Aged

KW - Risk Assessment

KW - Sex Factors

U2 - 10.1093/eurheartj/ehu081

DO - 10.1093/eurheartj/ehu081

M3 - Journal article

C2 - 24603310

SN - 0195-668X

VL - 35

SP - 1335

EP - 1344

JO - European Heart Journal

JF - European Heart Journal

IS - 20

ER -