A simplified biventricular defibrillator with fixed long detection intervals reduces implantable cardioverter defibrillator (ICD) interventions and heart failure hospitalizations in patients with non-ischaemic cardiomyopathy implanted for primary prevention: the RELEVANT [Role of long dEtection window programming in patients with LEft VentriculAr dysfunction, Non-ischemic eTiology in primary prevention treated with a biventricular ICD] study

Abstract

AimsTo investigate the efficacy and safety of a cardiac resynchronization therapy with cardioverter–defibrillator (CRT-D) device with simplified ventricular tachycardia management in patients with non-ischaemic heart failure (HF) and primary prevention implantable cardioverter defibrillator (ICD) indication.Methods and resultsProspective, controlled, parallel, multicentre, non-randomized study enrolling 324 primary prevention non-ischaemic HF patients implanted with CRT-D devices from 2004 to 2007: Protect group, 164 patients implanted with a Medtronic Insync III Protect device and Control group, 160 patients utilizing other Medtronic CRT-D devices.Efficacy was assessed by computing appropriate and inappropriate detections and therapies during follow-up; safety compared hospitalizations and syncopal events between groups. Ninety per cent of both ventricular and supraventricular tachyarrhythmias terminated within the 13–29 beat detection interval with the Protect algorithm. The Protect group showed a significantly better event-free survival to first delivered therapy for total (P = 0.0001), appropriately treated (P = 0.002), and inappropriately treated episodes (P = 0.017). The total number of delivered shocks was significantly lower in the Protect group (22 vs. 59, P < 0.0001). In the Protect group, a significantly reduced HF hospitalization (hazard ratio 0.38, 95% CI 0.15–0.98, P = 0.044) was observed without any increase of syncope or death.ConclusionA simplified CRT-D device with fixed long detection reduced overall ICD therapy burden and HF hospitalizations without entailing any additional adverse events in primary prevention non-ischaemic HF patients.

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

“…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]. In the earlier EMPIRIC study, standardized VT detection and ATP therapy parameters demonstrated a reduction in shocks when compared with physician-tailored treatment in a randomized assessment of 900 primary prevention patients [101].…”

“…In 2009, the Role of Long-Detection Window Programming in Patients with Left Ventricular Dysfunction, Non-Ischemic Etiology in Primary Prevention Treated with a Biventricular ICD (RELE-VANT) study confirmed and expanded the results of the PREPARE trial in a cohort of 324 primary prevention CRT-D patients with nonischemic cardiomyopathy [95]. The subjects were treated with simplified VT management, which implies much longer detection for VF episodes (30 of 40) compared with the control group (12 of 16) and a monitor-only window for VT. As in PREPARE, the RELE-VANT study group experienced a significantly reduced burden of ICD interventions (81% reduction) without increasing the incidence of syncope.…”

“…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].…”

Inappropriate ICD Shocks in Pediatric and Congenital Heart Disease Patients

“…54 A similar result was demonstrated for prolonged detection intervals in the RELEVANT study. 55 In one of the more significant studies on the issue, MADIT-RIT reported on outcomes using lenient programming strategies. One thousand five hundred primary prevention patients were randomized to one of three programming options: conventional therapy (4170 bpm VT zone with 2.5-s delay to shock, and 4200 bpm with a 1.0-s delay); high rate therapy (4200 bpm 2.5-s delay); and delayed therapy (4170 bpm with a 60-s delay, 4200 bpm with a 12-s delay, and 4 250 bpm with a 2.5-s delay).…”