Heart failure severity, inappropriate ICD therapy, and novel ICD programming: a MADIT-RIT substudy.
Daimee UA, Vermilye K, Rosero S, Schuger CD, Daubert JP, Zareba W, McNitt S, Polonsky B, Moss AJ, Kutyifa V. Heart failure severity, inappropriate ICD therapy, and novel ICD Programming: A MADIT-RIT Sub-Study. Pacing Clin Electrophysiol. 2017 Dec;40(12):1405-1411.
Pacing and clinical electrophysiology : PACE
BACKGROUND: The effects of heart failure (HF) severity on risk of inappropriate implantable cardioverter-defibrillator (ICD) therapy have not been thoroughly investigated. We aimed to study the association between HF severity and inappropriate ICD therapy in MADIT-RIT.
METHODS: MADIT-RIT randomized 1,500 patients to three ICD programming arms: conventional (Arm A), high-rate cut-off (Arm B: ≥200 beats/min), and delayed therapy (Arm C: 60-second delay for ≥170 beats/min). We evaluated the association between New York Heart Association (NYHA) class III (n = 256) versus class I-II (n = 251) and inappropriate ICD therapy in Arm A patients with ICD-only and cardiac resynchronization therapy with defibrillator (CRT-D). We additionally assessed benefit of novel ICD programming in Arms B and C versus Arm A by NYHA classification.
RESULTS: In Arm A, the risk of inappropriate therapy was significantly higher in those with NYHA III versus NYHA I-II for both ICD (hazard ratio [HR] = 2.55, confidence interval [CI]: 1.51-4.30, P < 0.001) and CRT-D patients (HR = 3.73, CI: 1.14-12.23, P = 0.030). This was consistent for inappropriate ATP and inappropriate ICD therapy < 200 beats/min, but not for inappropriate shocks. Novel ICD programming significantly reduced inappropriate therapy in patients with both NYHA III (Arm B vs Arm A: HR = 0.08, P < 0.001; Arm C vs Arm A: HR = 0.17, P < 0.001) and NYHA I-II (Arm B vs Arm A: HR = 0.25, P < 0.001; Arm C vs Arm A: HR = 0.28, P < 0.001).
CONCLUSION: Patients with more severe HF are at increased risk for inappropriate ICD therapy, particularly ATP due to arrhythmias < 200 beats/min. Novel programming with high-rate cut-off or delayed detection reduces inappropriate ICD therapies in both mild and moderate HF.
Medical Subject Headings
Cardiac Resynchronization Therapy; Defibrillators, Implantable; Female; Heart Failure; Humans; Male; Medical Overuse; Middle Aged; Randomized Controlled Trials as Topic; Retrospective Studies; Severity of Illness Index