Strategic programming of detection and therapy parameters in implantable cardioverter-defibrillators reduces shocks in primary prevention patients: results from the PREPARE (Primary Prevention Parameters Evaluation) study.
OBJECTIVE
Our purpose was to demonstrate that strategically chosen implantable cardioverter-defibrillator (ICD) ventricular tachycardia (VT) or ventricular fibrillation (VF) detection and therapy parameters can reduce the combined incidence of device-delivered shocks, arrhythmic syncope, and untreated sustained symptomatic VT/VF (morbidity index).


BACKGROUND
Strategically chosen ICD VT/VF detection and therapy parameters have been shown in previous studies to reduce the number of shocked episodes. In the PREPARE (Primary Prevention Parameters Evaluation) study, these prior strategies were combined with additional strategies specific to primary prevention patients.


METHODS
The PREPARE study was a prospective, cohort-controlled study that analyzed 700 patients (biventricular [Bi-V] ICD and non-Bi-V ICD) with primary prevention indications for an ICD from 38 centers followed for 1 year. VT/VF was detected for rates > or =182 beats/min that were maintained for at least 30 of 40 beats. Antitachycardia pacing was programmed as the first therapy for regular rhythms with rates of 182 to 250 beats/min, and supraventricular tachycardia discriminators were used for rhythms < or =200 beats/min. The control cohort consisted of 689 primary prevention patients from the EMPIRIC (Comparison of Empiric to Physician-Tailored Programming of Implantable Cardioverter Defibrillators Trial) (non-Bi-V ICD, physician arm only) and MIRACLE ICD (Multicenter InSync Implantable Cardioversion Defibrillation Randomized Clinical Evaluation) (Bi-V ICD) trials for whom VT/VF detection and therapy programming were not controlled.


RESULTS
The PREPARE programming significantly reduced the morbidity index incidence density (0.26 events/patient-year for PREPARE study patients vs. 0.69 control cohort, p = 0.003). The PREPARE study patients were less likely to receive a shock in the first year compared with control patients (9% vs. 17%, p < 0.01). The incidence of untreated VT and arrhythmic syncope was similar between the PREPARE study patients and the control cohort.


CONCLUSIONS
Strategically chosen VT/VF detection and therapy parameters can safely reduce shocks and other morbidities associated with ICD therapy in patients receiving an ICD for primary prevention indications. (PREPARE-Primary Prevention Parameters Evaluation; NCT00279279).
Wilkoff
Bruce L
BL
Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Director of Cardiac Pacing and Tachyarrhythmia Devices, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk F-15, Cleveland, Ohio 44195, USA. wilkofb@ccf.org
Williamson
Brian D
BD
Stern
Richard S
RS
Moore
Stephen L
SL
Lu
Fei
F
Lee
Sung W
SW
Birgersdotter-Green
Ulrika M
UM
Wathen
Mark S
MS
Van Gelder
Isabelle C
IC
Heubner
Brooke M
BM
Brown
Mark L
ML
Holloman
Keith K
KK
D000368:Aged; D016022:Case-Control Studies; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004554:Electric Countershock / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D013575:Syncope / Q000517:prevention & control; D017180:Tachycardia, Ventricular / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D014693:Ventricular Fibrillation / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*