Strategic Programming of Detection and Therapy Parameters in Implantable Cardioverter-Defibrillators Reduces Shocks in Primary Prevention Patients

Abstract

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).

2015 HRS/EHRA/APHRS/SOLAECE expert consensus statement on optimal implantable cardioverter-defibrillator programming and testing

“…In the PREPARE study, a primary prevention cohort of 700 patients was programmed with 30 of 40 detection intervals with ATP-first for VT between 182 and 250 bpm with SVT discriminators active up to 200 bpm. The results demonstrated a robust absolute risk reduction for shocks at 1 year from 17% to 9% without an increase in arrhythmic syncope when compared with historical controls [133]. Similar findings were noted in the RELEVANT study, which evaluated a cohort of patients with nonischemic heart disease and cardiac resynchronization defibrillators [95].…”

“…This strategy allows episodes to self-terminate without requiring device intervention and reduces inappropriate therapy for nonmalignant arrhythmias. The benefit of programming a prolonged detection duration (30 of 40 beats) was first reported in the Prevention Parameters Evaluation (PREPARE) study on exclusively primary prevention subjects (n ¼700), and compared outcomes to a historical ICD cohort programmed at "conventional detection delays" with about half programmed to 12 of 16 intervals within the programmed detection zone and half to 18 of 24 intervals [94]. The programming in PREPARE demonstrated a significant reduction in inappropriate shocks for supraventricular arrhythmia and in avoidable shocks for VT.…”

“…When modern algorithms are programmed to recommended parameters, clinically significant underdetection is rare. Large clinical trials on multiple shock-reduction strategies (including SVT-VT discrimination) report no or minimal and statistically insignificant increases in syncope [95,97,126,133]. Most reports do not include the causes of syncope and thus do not permit identification of whether discrimination algorithms contributed to any of the syncopal episodes by prolonging detection.…”

“…Several large clinical trials have established the safety and efficacy of ATP as a first-line therapy to treat even very fast VTs [93,95,101,133]. The use of first-line ATP involving VT at rates between 188 and 250 bpm in the PainFREE Rx II trial resulted in a 71% relative shock reduction [93].…”

Long‐Term Follow‐Up of Prophylactic Implantable Cardioverter‐Defibrillator–Only Therapy: Comparison of Ischemic and Nonischemic Heart Disease

“…14 Strategic programming can further reduce inappropriate device interventions. 28 The frequency of inappropriate delivered shocks can probably be further lowered, both by adaptations from software and hardware. 29,30 Limitations Because this is an observational study without control group, no statements about the benefit of ICD therapy can be made.…”