The epidemic of inadequate biventricular pacing in patients with persistent or permanent atrial fibrillation and its association with mortality.
BACKGROUND
We classified patients' atrial fibrillation (AF), assessed its impact on biventricular pacing (BIVP%), and determined whether AF classification or BIVP% independently correlate with mortality in cardiac resynchronization therapy defibrillator patients.


RESULTS
Cardiac resynchronization therapy defibrillator patients were classified as permanent (daily mean AF burden ≥23 hours), persistent (≥7 consecutive days of AF ≥23 hours/d), paroxysmal (≥1 day with AF ≥6 hours), or no/little AF (all others) using device-detected AF during the 6 months postimplant. We evaluated subsequent all-cause mortality using a multivariable Cox proportional hazard regression. Among 54 019 patients (age, 70±11 years; 73% male; follow-up, 2.3±1.2 years), 8% of patients each had permanent (N=4449), persistent (N=4237), and paroxysmal AF (N=4219). A high proportion of patients with permanent (69%) and persistent (62%) AF did not achieve high BIVP (>98%). Relative to no/little AF, patients with AF had increased mortality after adjusting for age, sex, BIVP, and shocks (permanent: hazard ratio=1.28 [1.19-1.38]; P<0.001; persistent: hazard ratio=1.51 [1.41-1.61]; P<0.001). Relative to patients with BIVP >98%, patients with reduced BIVP had increased mortality after adjusting for age, sex, AF, and shocks (90%-98%: hazard ratio=1.20 [1.15-1.26]; P<0.001; <90%: hazard ratio=1.32 [1.23-1.41]; P<0.001). High BIVP% was associated with the greatest mortality improvement in permanent AF among the AF classifications.


CONCLUSIONS
High BIVP% was not achieved in two thirds of 8686 patients with persistent or permanent AF, and these patients had an increased risk of death. A shift toward more aggressive rate control and more pacing may be necessary in patients with AF to maximize the benefits of cardiac resynchronization therapy.
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.). kevin.ousdigian@gmail.com.
Kevin T
KT
Ousdigian
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.).
P Peter
PP
Borek
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.).
Jodi L
JL
Koehler
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.).
J Thomas
JT
Heywood
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.).
Paul D
PD
Ziegler
From the Medtronic, Inc, Minneapolis, MN (K.T.O., J.L.K., P.D.Z.); Centennial Heart, Nashville, TN (P.P.B.); Scripps Clinic, San Diego, CA (J.T.H.); and Cleveland Clinic Foundation, OH (B.L.W.).
Bruce L
BL
Wilkoff
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods / Q000401:mortality* / Q000706:statistics & numerical data; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D002423:Cause of Death; D015331:Cohort Studies; D016208:Databases, Factual; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D005260:Female; D006333:Heart Failure / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D016019:Survival Analysis; D017211:Treatment Failure
atrial fibrillation; cardiac resynchronization therapy; heart failure; heart rate; mortality