title: A novel technique for the assessment of preoperative cardiovascular risk: reactive hyperemic response to short-term exercise.
abstract: BACKGROUND
  Perioperative vascular function has been widely studied using noninvasive techniques that measure reactive hyperemia as a surrogate marker of vascular function. However, studies are limited to a static setting with patients tested at rest. We hypothesized that exercise would increase reactive hyperemia as measured by digital thermal monitoring (DTM) in association to patients' cardiometabolic risk.
  
  
  METHODS
  Thirty patients (58 ± 9 years) scheduled for noncardiac surgery were studied prospectively. Preoperatively, temperature rebound (TR) following upper arm cuff occlusion was measured before and 10 minutes after exercise. Data are presented as means ± SD. Statistical analysis utilized ANOVA and Fisher's exact test, with P values <0.05 regarded as significant.
  
  
  RESULTS
  Following exercise, TR-derived parameters increased significantly (absolute: 0.53 ± 0.95 versus 0.04 ± 0.42°C, P=0.04, and % change: 1.78 ± 3.29 versus 0.14 ± 1.27 %, P=0.03). All patients with preoperative cardiac risk factors had a change in TR (after/before exercise, ΔTR) with values falling in the lower two tertiles of the study population (ΔTR <1.1%).
  
  
  CONCLUSIONS
  Exercise increased the reactive hyperemic response to ischemia. This dynamic response was blunted in patients with cardiac risk factors. The usability of this short-term effect for the preoperative assessment of endothelial function warrants further study.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Cologne, Cologne, Germany. robert.schier@gmx.net
authors.forename: Robert
authors.initials: R
authors.lastname: Schier
authors.forename: Jochen
authors.initials: J
authors.lastname: Hinkelbein
authors.forename: Hanke
authors.initials: H
authors.lastname: Marcus
authors.forename: Ashley
authors.initials: A
authors.lastname: Smallwood
authors.forename: Arlene M
authors.initials: AM
authors.lastname: Correa
authors.forename: Reza
authors.initials: R
authors.lastname: Mehran
authors.forename: Randa
authors.initials: R
authors.lastname: El-Zein
authors.forename: Bernhard
authors.initials: B
authors.lastname: Riedel
mesh_terms: D002318:Cardiovascular Diseases / Q000150:complications* / Q000601:surgery*; D003710:Demography; D015444:Exercise; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000150:complications* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013696:Temperature; D013997:Time Factors