title: Association between gait speed as a measure of frailty and risk of cardiovascular events after myocardial infarction.
abstract: OBJECTIVE
  This study sought to determine the additional clinical value of gait speed to Framingham risk score (FRS), cardiac function, and comorbid conditions in predicting cardiovascular events in patients with ST-segment elevation myocardial infarction.
  
  
  BACKGROUND
  There is growing evidence that gait speed is inversely associated with all-cause mortality, particularly cardiovascular mortality, among the elderly.
  
  
  METHODS
  We undertook a single-center prospective observational study of gait speed in 472 patients with ST-segment elevation myocardial infarction in Japan, between 2001 and 2008. Gait speeds were measured using a 200-m course before discharge in all patients, and we followed up cardiovascular events, which consist of cardiovascular deaths, nonfatal myocardial infarctions, and nonfatal ischemic strokes.
  
  
  RESULTS
  During the 2,596 person-years of follow-up, 83 patients (17.6%) experienced cardiovascular events. Cardiovascular events increased across decreasing tertiles of gait speed (fastest tertile: n = 5, 3.2%; middle tertile: n = 20, 12.6%; slowest tertile, n = 58, 36.7%). By multiple adjusted Cox proportional hazards analysis, gait speed was a significant and independent predictor of cardiovascular events (hazard ratio for increasing 0.1 m/s of gait speed: 0.71, 95% confidence interval [CI]: 0.63 to 0.81, p < 0.001). The addition of gait speed to the model incorporating FRS, B-type natriuretic peptide levels, and comorbidity index improved reclassification (net reclassification index: 32.8%, 95% CI: 17.4 to 48.3, p < 0.001) and the C-statistics with a reasonable global fit and calibration (C-statistics: from 0.703 [95% CI: 0.636 to 0.763] to 0.786 [95% CI: 0.738 to 0.829]).
  
  
  CONCLUSIONS
  Among patients with ST-segment elevation myocardial infarction, slow gait speed was significantly associated with an increased risk of cardiovascular events. (Gait Speed for Predicting Cardiovascular Events After Myocardial Infarction; NCT01484158).
authors.affiliation: Division of Cardiology, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Konishi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Akiyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakayama
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kiyokuni
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sumita
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ebina
authors.forename: Masami
authors.initials: M
authors.lastname: Kosuge
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hibi
authors.forename: Kengo
authors.initials: K
authors.lastname: Tsukahara
authors.forename: Noriaki
authors.initials: N
authors.lastname: Iwahashi
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Endo
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Maejima
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Saka
authors.forename: Katsutaka
authors.initials: K
authors.lastname: Hashiba
authors.forename: Kozo
authors.initials: K
authors.lastname: Okada
authors.forename: Masataka
authors.initials: M
authors.lastname: Taguri
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Seigo
authors.initials: S
authors.lastname: Sugiyama
authors.forename: Hisao
authors.initials: H
authors.lastname: Ogawa
authors.forename: Hironobu
authors.initials: H
authors.lastname: Sashika
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umemura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D005684:Gait; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000601:surgery; D062645:Percutaneous Coronary Intervention; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D016138:Walking / Q000706:statistics & numerical data*