title: Impaired renal function is associated with echocardiographic nonresponse and poor prognosis after cardiac resynchronization therapy.
abstract: OBJECTIVE
  Aims of this study were to investigate the effect of renal function on left ventricular (LV) reverse remodeling and long-term outcome after cardiac resynchronization therapy (CRT), and to explore the relation between LV reverse remodeling and changes in renal function at 6-month follow-up.
  
  
  BACKGROUND
  Renal insufficiency is highly prevalent in heart failure patients, including patients eligible for CRT, and is associated with poor prognosis.
  
  
  METHODS
  The study comprised 490 patients undergoing CRT. Response to CRT was defined as a decrease in LV end-systolic volume ≥15% at 6-month follow-up. Primary end point during long-term follow-up was all-cause mortality.
  
  
  RESULTS
  At baseline, mean estimated glomerular filtration rate (eGFR) was 70 ± 28 ml/min/1.73 m². At 6-month follow-up, 263 patients (54%) demonstrated response to CRT. Responders had an eGFR of 74 ± 26 ml/min/1.73 m² versus 64 ± 28 ml/min/1.73 m² in nonresponders (p < 0.001). During long-term follow-up, patients with an eGFR <60 ml/min/1.73 m² had higher mortality than patients with an eGFR of 60 to 90 ml/min/1.73 m² or an eGFR >90 ml/min/1.73 m² (p < 0.001). Finally, responders to CRT had preservation of renal function (ΔeGFR -0.6), whereas nonresponders had a slight worsening in renal function (ΔeGFR -4.7, p < 0.05).
  
  
  CONCLUSIONS
  Impaired renal function in CRT candidates is associated with nonresponse during 6-month follow-up. Additionally, patients with impaired renal function have worse long-term survival after CRT. Response to CRT results in preservation of renal function.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, the Netherlands.
authors.forename: Rutger J
authors.initials: RJ
authors.lastname: Van Bommel
authors.forename: Sjoerd A
authors.initials: SA
authors.lastname: Mollema
authors.forename: C Jan Willem
authors.initials: CJ
authors.lastname: Borleffs
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertini
authors.forename: Claudia
authors.initials: C
authors.lastname: Ypenburg
authors.forename: Nina Ajmone
authors.initials: NA
authors.lastname: Marsan
authors.forename: Victoria
authors.initials: V
authors.lastname: Delgado
authors.forename: Ernst E
authors.initials: EE
authors.lastname: Van Der Wall
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000639:trends; D004452:Echocardiography / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries; D051437:Renal Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome