title: Impact of renal insufficiency on long-term clinical outcome in patients with heart failure treated by cardiac resynchronization therapy.
abstract: BACKGROUND
  Renal insufficiency is recognized as a predictor of mortality and adverse outcome in heart failure (HF) patients. However, the long-term clinical outcome of cardiac resynchronization therapy (CRT) in Japanese HF patients with renal insufficiency remains uncertain.
  
  
  METHODS
  We evaluated 67 consecutive patients who underwent CRT at our hospital. The patients were divided into two groups according to a baseline estimated glomerular filtration rate (e-GFR) cut-off value of 50ml/min, which is defined as the time at which patients should be referred to a nephrologist, by the Japanese Society of Nephrology. Follow-up echocardiographic findings and renal function were examined at 3-6 months after CRT. Then, we compared long-term clinical outcomes between the two groups, and analyzed the effect of CRT on renal function, echocardiographic parameters and cardiac survival.
  
  
  RESULTS
  During a mean follow-up period of 30.3 months, patients with advanced renal insufficiency (e-GFR<50ml/min) had significant higher all-cause mortality (log-rank p=0.033) and higher cardiac mortality combined with HF hospitalization (log-rank p=0.017) than patients with e-GFR≥50ml/min. Multivariate analysis revealed that advanced renal insufficiency was an independent predictor of cardiac mortality combined with HF hospitalization (odds ratio=3.01, p=0.008). Subgroup analysis in the baseline advanced renal insufficiency group revealed that patients with preserved renal function by CRT (<10% reduction in e-GFR) had a higher rate of decrease of left ventricular end-systolic diameter (-14.0% vs. -0.8%, p=0.023) and lower cardiac mortality combined with HF hospitalization (log-rank p=0.029) compared with patients with deterioration of renal function (≥10% reduction in e-GFR).
  
  
  CONCLUSIONS
  The present study suggests that advanced renal insufficiency is quite useful for the prediction of worsening clinical outcomes in HF patients treated by CRT. Preservation of renal function by CRT brings about better cardiac survival through prevention of adverse cardiac events, even in HF patients with advanced renal insufficiency.
authors: Department of Cardiology, Yokohama City University Hospital, Yokohama, Japan. j_hosoda@yokohama-cu.ac.jp
authors: Junya
authors: J
authors: Hosoda
authors: Toshiyuki
authors: T
authors: Ishikawa
authors: Kohei
authors: K
authors: Matsushita
authors: Katsumi
authors: K
authors: Matsumoto
authors: Yuichiro
authors: Y
authors: Kimura
authors: Mihoko
authors: M
authors: Miyamoto
authors: Hideyuki
authors: H
authors: Ogawa
authors: Takeshi
authors: T
authors: Takamura
authors: Teruyasu
authors: T
authors: Sugano
authors: Tomoaki
authors: T
authors: Ishigami
authors: Kazuaki
authors: K
authors: Uchino
authors: Kazuo
authors: K
authors: Kimura
authors: Satoshi
authors: S
authors: Umemura
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D051437:Renal Insufficiency / Q000150:complications*