Development and validation of an ankle brachial index model for the prediction of cardiovascular events

Ankle Brachial Index Collaboration

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Background The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS. Design An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events. Methods Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events. Results In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women. Conclusions An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.
Original languageEnglish
Pages (from-to)310-320
Number of pages11
JournalEuropean Journal of Preventive Cardiology
Volume21
Issue number3
Early online date23 Dec 2013
DOIs
Publication statusPublished - Mar 2014

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Cardiovascular Models
Ankle Brachial Index

Keywords

  • ankle brachial index
  • cardiovascular diseases
  • risk assessment

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Development and validation of an ankle brachial index model for the prediction of cardiovascular events. / Ankle Brachial Index Collaboration.

In: European Journal of Preventive Cardiology, Vol. 21, No. 3, 03.2014, p. 310-320.

Research output: Contribution to journalArticle

@article{44323ef6f20647a4ac6c08ea07210914,
title = "Development and validation of an ankle brachial index model for the prediction of cardiovascular events",
abstract = "Background The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS. Design An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events. Methods Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events. Results In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95{\%} CI 0.599 to 0.737) in men and 0.578 (95{\%} CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95{\%} CI 0.612 to 0.749) and large increase in women to 0.690 (95{\%} CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3{\%} (95{\%} CI 0.0 to 7.6{\%}, p = 0.050) and 9.6{\%} (95{\%} CI 6.1 to 16.4{\%}, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19{\%} resulted in higher NRI of 15.9{\%} (95{\%} CI 6.1 to 20.6{\%}, p < 0.001) in men and 23.3{\%} (95{\%} CI 13.8 to 62.5{\%}, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0{\%} (95{\%} CI 2.3 to 4.2{\%}, p = 0.567) in men and 1.1{\%} (95{\%} CI 1.9 to 4.0{\%}, p = 0.483) in women. Conclusions An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.",
keywords = "ankle brachial index, cardiovascular diseases, risk assessment",
author = "FGR Fowkes and GD Murray and I. Butcher and Folsom, {A. R.} and Hirsch, {A. T.} and DJ Couper and G. deBacker and M. Kornitzer and AB Newman and KC Sutton-Tyrell and M. Cushman and AJ Lee and JF Price and d'Agostino, {R. B.} and Murabito, {J. M.} and PE Norman and Masaki, {K. H.} and Bouter, {L. M.} and Heine, {R. J.} and Stehouwer, {C. D. A.} and McDermott, {M. M.} and HEJH Stoffers and Knottnerus, {J. A.} and M. Ogren and B. Hedblad and W Koenig and C Meisinger and JA Cauley and OH Franco and Hunink, {M. G. M.} and A. Hofman and Witteman, {J. C.} and Criqui, {M. H.} and Langer, {R. D.} and Hiatt, {W. R.} and RF Hamman and {Ankle Brachial Index Collaboration}",
year = "2014",
month = "3",
doi = "10.1177/2047487313516564",
language = "English",
volume = "21",
pages = "310--320",
journal = "European Journal of Preventive Cardiology",
issn = "2047-4873",
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TY - JOUR

T1 - Development and validation of an ankle brachial index model for the prediction of cardiovascular events

AU - Fowkes, FGR

AU - Murray, GD

AU - Butcher, I.

AU - Folsom, A. R.

AU - Hirsch, A. T.

AU - Couper, DJ

AU - deBacker, G.

AU - Kornitzer, M.

AU - Newman, AB

AU - Sutton-Tyrell, KC

AU - Cushman, M.

AU - Lee, AJ

AU - Price, JF

AU - d'Agostino, R. B.

AU - Murabito, J. M.

AU - Norman, PE

AU - Masaki, K. H.

AU - Bouter, L. M.

AU - Heine, R. J.

AU - Stehouwer, C. D. A.

AU - McDermott, M. M.

AU - Stoffers, HEJH

AU - Knottnerus, J. A.

AU - Ogren, M.

AU - Hedblad, B.

AU - Koenig, W

AU - Meisinger, C

AU - Cauley, JA

AU - Franco, OH

AU - Hunink, M. G. M.

AU - Hofman, A.

AU - Witteman, J. C.

AU - Criqui, M. H.

AU - Langer, R. D.

AU - Hiatt, W. R.

AU - Hamman, RF

AU - Ankle Brachial Index Collaboration

PY - 2014/3

Y1 - 2014/3

N2 - Background The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS. Design An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events. Methods Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events. Results In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women. Conclusions An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

AB - Background The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS. Design An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events. Methods Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events. Results In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women. Conclusions An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

KW - ankle brachial index

KW - cardiovascular diseases

KW - risk assessment

U2 - 10.1177/2047487313516564

DO - 10.1177/2047487313516564

M3 - Article

VL - 21

SP - 310

EP - 320

JO - European Journal of Preventive Cardiology

JF - European Journal of Preventive Cardiology

SN - 2047-4873

IS - 3

ER -