title: Prediction of long-term outcome of cardiac resynchronization therapy by acute pressure-volume loop measurements.
abstract: OBJECTIVE
  Invasive assessment of acute haemodynamic response to biventricular pacing has been proposed as a tool to determine individual response and to optimize the effects of CRT. However, the long-term results of this approach have been poorly studied. The present study relates acute haemodynamic effects of CRT to long-term outcome.
  
  
  RESULTS
  Forty-one patients were analysed in the present study. During temporary biventricular pacing before implantation, acute changes in LV pump function were assessed by pressure-volume loop measurements and related to long-term response after CRT. In the study population [30 (71%) men, NYHA class 2.9 ± 0.4, EF 28 ± 7%, QRS 150 ± 25 ms], baseline mean stroke work (SW) and dP/dt(max) were 4.6 ± 2.6 L × mmHg and 874 ± 259 mmHg/s, respectively. During biventricular pacing, mean SW and dP/dt(max) increased significantly by 43 ± 39% (+ 2.2 ± 2.4 L × mmHg, P < 0.001) and 13 ± 18% (+ 96 ± 136 mmHg/s, P < 0.001), respectively. In long-term responders (n = 29, 71%) compared with non-responders (n = 12, 29%), the acute increase in SW was significantly higher (+57 ± 33% vs. + 10 ± 30%, P < 0.001), whereas the acute increase in dP/dt(max) was not significantly different between responders and non-responders (+ 15 ± 18% vs. 6 ± 15%, P = 0.139). Receiver operating characteristic (ROC) curve analysis indicated that SW was superior to dP/dt(max), QRS duration and LV dyssynchrony in prediction of response to CRT. A cut-off value for SW of 20% yielded a sensitivity of 90% and specificity of 75% to predict reverse remodelling at 6 months.
  
  
  CONCLUSIONS
  Invasive assessment of acute haemodynamics is a reliable tool to determine individual response to CRT. An acute increase in SW predicts long-term response to CRT with a higher accuracy than an acute increase in dP/dt(max), baseline QRS duration, and degree of LV mechanical dyssynchrony.
authors.affiliation: Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands. gj.deroest@vumc.nl
authors.forename: Gerben J
authors.initials: GJ
authors.lastname: de Roest
authors.forename: Cornelis P
authors.initials: CP
authors.lastname: Allaart
authors.forename: Sebastiaan A
authors.initials: SA
authors.lastname: Kleijn
authors.forename: Peter Paul H M
authors.initials: PP
authors.lastname: Delnoy
authors.forename: LiNa
authors.initials: L
authors.lastname: Wu
authors.forename: Matthijs L
authors.initials: ML
authors.lastname: Hendriks
authors.forename: Jean G F
authors.initials: JG
authors.lastname: Bronzwaer
authors.forename: Albert C
authors.initials: AC
authors.lastname: van Rossum
authors.forename: Carel C
authors.initials: CC
authors.lastname: de Cock
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000628:therapy*