title: Quadriceps isometric strength as a predictor of exercise capacity in coronary artery disease patients.
abstract: BACKGROUND
  Quadriceps strength is related to exercise capacity in normal subjects and different patient populations, but the relationship between maximal quadriceps isometric strength (QIS) and different exercise capacity levels in coronary artery disease (CAD) patients has not been systematically evaluated yet.
  
  
  METHODS
  We studied 621 patients (60.6 ± 9.9 years, 538 males) with recent coronary artery bypass grafting or myocardial infarction, who underwent treadmill exercise testing, maximal QIS measurement (hand-held dynamometry), and coronary arteriography. Maximal QIS was expressed as absolute value (kg), %bodyweight, and %predicted maximum. Logistic regression was used to assess the relationship of maximal QIS, age, sex, number of diseased coronary vessels, peak systolic blood pressure, peak heart rate, brain natriuretic peptide, and left ventricular ejection fraction with 5, 7, and 10 estimated metabolic equivalents (eMETs) exercise capacity levels.
  
  
  RESULTS
  Maximal QIS %bodyweight was the strongest predictor of exercise capacity in each eMETs category. Receiver-operating characteristics curves identified maximal QIS of 46, 51, and 59 % bodyweight as the best predictive cut offs for 5, 7 and 10 eMETs, respectively, with positive predictive values of 0.72, 0.66, and 0.67, respectively.
  
  
  CONCLUSIONS
  Maximal QIS is related with eMETs levels reached at exercise testing in CAD patients, and identified maximal QIS cut-off values for eMETs prediction may be used to set strength training goals according to patients' needs with regard to habitual physical activity level. Hand-held dynamometry may meet the need of easiness of use and low cost required for strength evaluation in large-scale clinical trials.
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan Kitasato University Hospital, Sagamihara, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kamiya
authors.affiliation: Scientific Institute of Veruno, Veruno, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mezzani
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Hotta
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Shimizu
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kamekawa
authors.affiliation: Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Noda
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan Kitasato University, Sagamihara, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Yamaoka-Tojo
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan Kitasato University, Sagamihara, Japan.
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Matsunaga
authors.affiliation: Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan Kitasato University, Sagamihara, Japan tak9999@med.kitasato-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Masuda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D005080:Exercise Test / Q000295:instrumentation; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D052097:Quadriceps Muscle / Q000503:physiopathology*; D012372:ROC Curve; D015203:Reproducibility of Results
keywords: Cardiac rehabilitation; coronary artery disease; exercise capacity; muscle strength