title: Transthoracic echocardiography for non-invasive assessment of coronary vasodilator function after DES implantation.
abstract: OBJECTIVE
  Coronary vasodilator dysfunction has been reported after drug-eluting stent (DES) implantation. Recent ESC guidelines suggest that transthoracic echocardiography (TTE) may be considered for assessment of coronary flow reserve (CFR) and microvascular disease in patients with stable angina, but its reliability has not been tested in patients with DES. We sought to assess the agreement between TTE (CFRTTE) and invasive thermodilution-derived CFR (CFRThermodilution) as well as their association with index of microcirculatory resistance (IMR) in mid-term follow-up after percutaneous coronary intervention for acute coronary syndrome.
  
  
  RESULTS
  CFRTTE and CFRThermodilution were assessed 3 months after DES implantation in the left anterior descending artery in 24 patients. Patients with haemodynamically significant epicardial stenosis (fractional flow reserve <0.75) were excluded. Correlation between the two methods was good (r = 0.71, P < 0.001), but CFRThermodilution (mean ± SD) tended to be higher (3.17 ± 1.00 vs. 2.87 ± 0.72; mean difference 0.29, 95% confidence interval -0.06 to 0.59). In Bland-Altman analysis, there was a trend towards a greater difference in the range of higher invasive values. Nevertheless, TTE was successful in discriminating moderately impaired CFR (≤2.5) (P = 0.001) and severely impaired CFR (≤2.0) (P < 0.001) when compared with an invasive method. No association between either CFR measurements vs. IMR measurement was detected, suggesting that in addition to microcirculatory function, CFR also accounts for epicardial vasodilator function in the absence of haemodynamically significant stenosis.
  
  
  CONCLUSIONS
  TTE is a feasible and reliable method for the assessment of CFR and vasodilator dysfunction after DES implantation. Values obtained with this method successfully find abnormal CFR confirmed with the invasive thermodilution method.
authors.affiliation: Heart Centre Turku University Hospital and University of Turku, Hämeentie 9, Turku 20520, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Varho
authors.affiliation: Department of Cardiology, Satakunta Central Hospital, Pori, Finland.
authors.forename: Pasi P
authors.initials: PP
authors.lastname: Karjalainen
authors.affiliation: Department of Cardiology, Satakunta Central Hospital, Pori, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Ylitalo
authors.affiliation: Heart Centre Turku University Hospital and University of Turku, Hämeentie 9, Turku 20520, Finland.
authors.forename: Juhani K
authors.initials: JK
authors.lastname: Airaksinen
authors.affiliation: Department of Cardiology, Satakunta Central Hospital, Pori, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Mikkelsson
authors.affiliation: Department of Cardiology, Central Ostrobothnia Central Hospital, Kokkola, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Sia
authors.affiliation: Heart Centre Turku University Hospital and University of Turku, Hämeentie 9, Turku 20520, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Pietilä
authors.affiliation: Heart Centre Turku University Hospital and University of Turku, Hämeentie 9, Turku 20520, Finland tuoski@utu.fi.
authors.forename: Tuomas O
authors.initials: TO
authors.lastname: Kiviniemi
mesh_terms: D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000628:therapy*; D003326:Coronary Circulation; D054855:Drug-Eluting Stents; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D011446:Prospective Studies; D012307:Risk Factors; D020123:Sirolimus / Q000008:administration & dosage; D013815:Thermodilution; D016896:Treatment Outcome; D014664:Vasodilation
chemical_list: D007166:Immunosuppressive Agents; D020123:Sirolimus
keywords: Coronary flow reserve; Drug-eluting stent; Index of microcirculatory resistance; Thermodilution