title: Ampere Hour as a Predictor of Cardiac Resynchronization Defibrillator Pulse Generator Battery Longevity: A Multicenter Study.
abstract: BACKGROUND
  Cardiac resynchronization defibrillator (CRT-D) devices improve survival for New York Heart Association classes II-IV systolic heart failure patients with QRS > 120 ms and left ventricular ejection fraction < 35%. A limitation of 100% CRT pacing is excess battery depletion and pulse generator (PG) replacement compared to VVI or dual-chamber systems. Ampere hour (Ah) measures PG battery capacity and may predict CRT-D device longevity.
  
  
  METHODS
  We performed a multicenter retrospective study of all CRT-D devices implanted at our centers from August 1, 2008 to December 31, 2010. Analysis was performed for survival to elective replacement indicator (ERI) between 1.0 Ah, 1.4 Ah, and 2.0 Ah devices, per manufacturers' specifications.
  
  
  RESULTS
  One thousand three hundred and two patients were studied through December 31, 2014. Patients were followed for an average of 3.0 ± 1.3 years (794 1.0 Ah, 322 2.0 Ah, and 186 1.4 Ah devices under study). CRT-D generator ERI occurred in 13.5% of 1.0 Ah systems (107 out of 794), versus 3.8% in 1.4 Ah (seven out of 186), and 0.3% in 2.0 Ah devices (one out of 322) over mean follow-up of 3.0 years. Odds ratio (OR) for reaching ERI with 1.0 Ah device versus 1.4 Ah or 2.0 Ah was 9.73, P < 0.0001. Univariate predictors for ERI included 1.0 Ah device and LV pacing output >3V @ 1 ms (OR: 3.74, P < 0.001). LV impedance >1,000 ohms predicted improved device survival (OR: 0.38, P = 0.0025).
  
  
  CONCLUSIONS
  CRT-D battery capacity measured by Ah is a strong predictor of survival to ERI for modern systems. Further study on cost and morbidity associated with early PG change in 1.0 Ah systems is warranted.
authors.affiliation: Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Ellis
authors.affiliation: Vanderbilt University Medical School, Nashville, Tennessee.
authors.forename: Deanna I
authors.initials: DI
authors.lastname: Dickerman
authors.affiliation: Vanderbilt Heart and Vascular Institute, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Jodi M
authors.initials: JM
authors.lastname: Orton
authors.affiliation: Henry Ford Hospital Detroit, Detroit, Michigan.
authors.forename: Sohail
authors.initials: S
authors.lastname: Hassan
authors.affiliation: University of Michigan/Cardiovascular Center, Ann Arbor, Michigan.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Good
authors.affiliation: Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Okabe
authors.affiliation: Cooper Health System, Camden, New Jersey.
authors.forename: John A
authors.initials: JA
authors.lastname: Andriulli
authors.affiliation: North Ohio Heart Center, Elyria, Ohio.
authors.forename: Kara J
authors.initials: KJ
authors.lastname: Quan
authors.affiliation: Cardiac Electrophysiology Laboratory, Philadelphia, Pennsylvania.
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Greenspon
mesh_terms: D000368:Aged; D058409:Cardiac Resynchronization Therapy Devices / Q000706:statistics & numerical data*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D020878:Device Removal / Q000379:methods / Q000706:statistics & numerical data*; D011211:Electric Power Supplies / Q000706:statistics & numerical data*; D004735:Energy Transfer; D004868:Equipment Failure / Q000706:statistics & numerical data; D019544:Equipment Failure Analysis / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
keywords: Ampere hour; ICD; battery; defibrillator; longevity; resynchronization