title: Coronary flow velocity reserve during pharmacologic stress echocardiography with normal contractility adds important prognostic value in diabetic and nondiabetic patients.
abstract: BACKGROUND
  Coronary flow velocity reserve (CFVR) increases the diagnostic sensitivity of stress echocardiography. The aim of this study was to evaluate the prognostic value of CFVR in patients without new wall motion abnormalities during pharmacologic stress echocardiography.
  
  
  METHODS
  The outcomes of 651 patients with normal wall motion response during stress echocardiography with dobutamine up to 50 μg/kg/min (n = 351) or dipyridamole up to 0.84 mg/kg over 4 min (n = 300) were evaluated. CFVR was calculated simultaneously in the distal territory of the left anterior descending coronary artery. CFVR ≥ 2 was defined as normal. Major events considered during follow-up were cardiovascular death, myocardial infarction, and late myocardial revascularization.
  
  
  RESULTS
  Normal CFVR was recorded in 523 patients and reduced CFVR in 128. During a mean follow-up period of 34.6 ± 18 months, 48 major events occurred, in 25 patients (4.8%) with normal and 23 patients (18%) with reduced CFVR; event-free survival was significantly different between patients with normal versus abnormal CFVR (P < .0001). Diabetes increased risk only in patients with abnormal CFVR (P = .05). In the multivariate analysis, CFVR and history of smoking were the only independent predictors of combined morbidity and mortality. Abnormal CFVR was associated with a higher event rate, independently of the pharmacologic stress technique used. The event hazard ratio was inversely proportional to CFVR.
  
  
  CONCLUSIONS
  CFVR was an independent predictor of mortality after pharmacologic stress echocardiography with normal wall motion, and the degree of decrease was associated with increased risk. Diabetes worsened prognosis only with abnormal CFVR.
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina. Electronic address: lowensteinjorge@hotmail.com.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Lowenstein
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Cristian
authors.initials: C
authors.lastname: Caniggia
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Graciela
authors.initials: G
authors.lastname: Rousse
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Miguel
authors.initials: M
authors.lastname: Amor
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: María E
authors.initials: ME
authors.lastname: Sánchez
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Diego
authors.initials: D
authors.lastname: Alasia
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Norberto
authors.initials: N
authors.lastname: Casso
authors.affiliation: Polimedic, Santa Rosa, Argentina.
authors.forename: Alicia
authors.initials: A
authors.lastname: García
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zambrana
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Diego M
authors.initials: DM
authors.lastname: Lowenstein Haber
authors.affiliation: Investigaciones Médicas, Buenos Aires, Argentina.
authors.forename: Victor
authors.initials: V
authors.lastname: Darú
mesh_terms: D000368:Aged; D001118:Argentina / Q000453:epidemiology; D015897:Comorbidity; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000401:mortality* / Q000503:physiopathology*; D048909:Diabetes Complications / Q000000981:diagnostic imaging / Q000401:mortality* / Q000503:physiopathology*; D004280:Dobutamine; D004452:Echocardiography / Q000706:statistics & numerical data*; D005080:Exercise Test / Q000379:methods; D005260:Female; D053805:Fractional Flow Reserve, Myocardial; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D004280:Dobutamine
keywords: Coronary flow velocity reserve; Risk assessment; Stress echocardiographic prognosis; Stress echocardiography