title: Effect of atrioventricular optimization on circulating N-terminal pro brain natriuretic peptide following cardiac resynchronization therapy.
abstract: OBJECTIVE
  Following CRT, atrioventricular (AV) optimization is not routinely practised. To evaluate its clinical utility, we examined the effect of AV delay optimization on the prognostic biomarker NT-proBNP.
  
  
  RESULTS
  We prospectively studied 72 patients (mean age 73 ± 12.5 years, 70.8% male, 55.6% ischaemic) undergoing iterative AV optimization. Patients were divided into those whose nominal setting appeared ideal and not changed (Group 1, n = 22) and those whose AV delay was optimized (Group 2, n = 50). All patients underwent NT-proBNP assessment prior to CRT, and pre- and a median 5 days post-optimization. Compared with Group 1, NT-proBNP fell significantly in Group 2 patients (median 474 pg/mL) following optimization (P = 0.00001). A significant change in filling pattern (defined as a change in AV delay >50 ms) was required in 30% of patients, and it was this subgroup that derived the greater reduction in NT-proBNP levels [-1407 pg/mL, interquartile range (IQR) -3042 to -346 pg/mL] compared with those requiring <50 ms AV delay change (-125 pg/mL, IQR -1038 to 6 pg/mL), P = 0.0011. The benefit of AV optimization was principally observed in reverse remodelling non-responders (median -2167 pg/mL, IQR -3042 to -305 pg/mL) and in patients with a pseudonormal or restrictive filling pattern (median -1407 pg/mL, IQR -2809 to -342 pg/mL), compared with those with more benign diastolic filling (median - 264 pg/mL, IQR -1038 to -21 pg/mL), P = 0.033.
  
  
  CONCLUSIONS
  In one-third of patients, major filling pattern changes are achieved with AV optimization, associated with subsequent rapid falls in NT-proBNP. The greater the AV delay change, the larger the NT-proBNP fall, and non-responders and those with restrictive or pseudonormal filling despite CRT are most likely to benefit.
authors: St George's Healthcare NHS Trust, Department of Cardiology, Blackshaw Road, London, UK. nesan_s@hotmail.com
authors: Nesan
authors: N
authors: Shanmugam
authors: Ana Garcia
authors: AG
authors: Campos
authors: Oscar
authors: O
authors: Prada-Delgado
authors: Mukhtar
authors: M
authors: Bizrah
authors: Oswaldo
authors: O
authors: Valencia
authors: Sue
authors: S
authors: Jones
authors: Paul
authors: P
authors: Collinson
authors: Lisa
authors: L
authors: Anderson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D020257:Ventricular Remodeling / Q000502:physiology
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain