Preimplantation B-type natriuretic peptide concentration is an independent predictor of future appropriate implantable defibrillator therapies.
OBJECTIVE
To assess prospectively whether preimplantation B-type natriuretic peptide (BNP) and C reactive protein (CRP) concentrations predict future appropriate therapies from an implantable cardioverter-defibrillator (ICD).


METHODS
Prospective cohort study conducted in a tertiary cardiac care centre.


METHODS
345 consecutive patients undergoing first time ICD implantation were prospectively studied. Serum BNP and CRP concentrations were obtained the day before ICD implantation. Patients were followed up with device interrogation to assess for appropriate shocks or antitachycardia pacing. Inappropriate therapies were excluded. Mean (SD) follow up was 13 (5) months.


RESULTS
Patients had ischaemic (71%), primary dilated (17%), and valvar or other cardiomyopathies (12%). About half (52%) had ICDs implanted for primary prevention. Sixty three (18%) received appropriate ICD therapies. Serum creatinine, beta blocker, statin, and angiotensin converting enzyme inhibitor usage did not differ between therapy and no therapy groups. By univariate comparison, ejection fraction (p = 0.048), not taking amiodarone (p = 0.033), and BNP concentration (p = 0.0003) were risk factors for ICD therapy. However, by Cox regression multivariate analysis, only BNP above the 50th centile was a significant predictor (hazard ratio 2.19, 95% confidence interval 1.07 to 4.71, p = 0.040). Median BNP was 573 ng/l versus 243 ng/l in therapy and no therapy patients, respectively (p = 0.0003). More patients with BNP above the 50th centile (27% v 10%, p = 0.006) received ICD therapies.


CONCLUSIONS
A single preimplantation BNP concentration determination is independently predictive of ICD therapies in patients with cardiomyopathies undergoing first time ICD implantation. CRP was not independently predictive of ICD therapies when compared with BNP.
Verma
A
A
Department of Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Kilicaslan
F
F
Martin
D O
DO
Minor
S
S
Starling
R
R
Marrouche
N F
NF
Almahammed
S
S
Wazni
O M
OM
Duggal
S
S
Zuzek
R
R
Yamaji
H
H
Cummings
J
J
Chung
M K
MK
Tchou
P J
PJ
Natale
A
A
D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D003324:Coronary Artery Disease / Q000628:therapy*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein