title: Prognostic role of coronary flow reserve for left ventricular functional improvement after cardiac resynchronization therapy in patients with dilated cardiomyopathy.
abstract: OBJECTIVE
  The aim of the study was to assess the value of coronary flow reserve (CFR) for predicting improvement of left ventricular function after cardiac resynchronization therapy (CRT).
  
  
  RESULTS
  Study population included 40 patients (mean age 58 ± 9 years) with heart failure (ejection fraction 25, 7 ± 5, 4%) and QRS duration of 158 ± 22 ms, planned for CRT. Before and after CRT implantation, CFR was measured non-invasively during hyperaemia induced with adenosine. Responders were defined by decrease in end-systolic volume ≥15%. Follow-up echocardiography and CFR measurements were obtained after 6 months. At baseline there was no significant difference in left ventricular ejection fraction (LVEF), QRS duration, 6 min walk test distance and coronary flow velocity at rest between responder (n = 26) vs. non-responder group (n = 14, P = ns). Before CRT implantation, responders compared with non-responders, showed a greater increase in coronary flow velocity during hyperaemia, and consequently higher CFR: 2.41 ± 0.60 vs. 1.61 ± 0.45 (P = 0.001). There was significant correlation between CFR before CRT implantation and LVEF after 6 months (r = 0.545, P = 0.001). End-diastolic, end-systolic left ventricular diameter, and CFR before CRT were predictors of LV functional improvement. By multivariate analysis, only CFR before CRT was independent predictor of left ventricular recovery in the follow-up period (P = 0.001).
  
  
  CONCLUSIONS
  Our results demonstrate that preserved CFR in patients with dilated cardiomyopathy is predictive of left ventricular improvement after CRT implantation.
authors: Clinical Center of Serbia, Cardiology Clinic, Medical School, University of Belgrade, Koste Todorovica 8, 11000 Belgrade, Serbia skali.ana7@gmail.com.
authors: Ana
authors: A
authors: Djordjevic Dikic
authors: Pacemaker Center, Clinical Center of Serbia, Medical School, University of Belgrade, Belgrade, Serbia.
authors: Gabrijela
authors: G
authors: Nikcevic
authors: Pacemaker Center, Clinical Center of Serbia, Medical School, University of Belgrade, Belgrade, Serbia.
authors: Srdjan
authors: S
authors: Raspopovic
authors: Pacemaker Center, Clinical Center of Serbia, Medical School, University of Belgrade, Belgrade, Serbia.
authors: Velibor
authors: V
authors: Jovanovic
authors: Clinical Center of Serbia, Cardiology Clinic, Medical School, University of Belgrade, Koste Todorovica 8, 11000 Belgrade, Serbia.
authors: Milorad
authors: M
authors: Tesic
authors: Clinical Center of Serbia, Cardiology Clinic, Medical School, University of Belgrade, Koste Todorovica 8, 11000 Belgrade, Serbia.
authors: Branko
authors: B
authors: Beleslin
authors: Clinical Center of Serbia, Cardiology Clinic, Medical School, University of Belgrade, Koste Todorovica 8, 11000 Belgrade, Serbia.
authors: Jelena
authors: J
authors: Stepanovic
authors: Clinical Center of Serbia, Cardiology Clinic, Medical School, University of Belgrade, Koste Todorovica 8, 11000 Belgrade, Serbia.
authors: Vojislav
authors: V
authors: Giga
authors: Pacemaker Center, Clinical Center of Serbia, Medical School, University of Belgrade, Belgrade, Serbia.
authors: Goran
authors: G
authors: Milasinovic
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000628:therapy; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D053805:Fractional Flow Reserve, Myocardial; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Cardiac resynchronization therapy; Coronary flow reserve; Dilated cardiomyopathy