Heart failure severity, inappropriate icd therapy, and novel icd programming: A MADIT-RIT sub-study
Daimee U, Vermilye K, Schuger CD, Daubert JP, Zareba W, Rosero S, McNitt S, Polonsky S, Moss AJ, Kutyifa V. Heart failure severity, inappropriate icd therapy, and novel icd programming: A MADIT-RIT sub-study. Heart Rhythm. 2017;14(5):S498-S499.
Background: The effect of heart failure (HF) severity on inappropriate ICD therapy has not been thoroughly investigated. Objective: To determine the relationship between HF severity and inappropriate ICD therapy and the effect of novel ICD programming on this relationship. Methods: MADIT-RIT randomized patients to three ICDprogramming arms: conventional (Arm A), high-rate cut-off (Arm B: ≥200 beats per minute), and delayed therapy (Arm C: 60-second delay). We evaluated the impact of New York Heart Association (NYHA) Class III (n=256) versus Class I-II (n=251) on inappropriate ICD therapy in Arm A patients (n=514). We also assessed the benefit of novel ICDprogramming in Arms B and C relative to Arm A patients. Results: In Arm A patients, the overall risk of inappropriatetherapy was significantly higher in those with NYHA III versus NYHA I-II (HR=2.72, 95% CI: 1.71-4,34, p<0.001). This was consistent for inappropriate ATP (NYHA III vs. I-II: HR=2.73, 95% CI: 1.71-4.36, p<0.001), but not inappropriateshock (NYHA III vs. I-II: HR=1.37, 95% CI: 0.54-3.43, p=0.509). Patients with NYHA III in the conventional therapy arm were significantly more likely to experience inappropriatetherapy fo heart rate (HR)<200 bpm (NYHA III vs. I-II: HR=2.96, 95% CI: 1.82-4.81, p<0.001) but not for HR≥200 bpm (NYHA III vs. I-II: HR=1.07, 95% CI: 0.34-3.31, p=0.913). Novel ICD programming significantly reduced the risk of inappropriate ICD therapy in patients with NYHA III (Arm B vs. A: HR=0.09, p<0.001; Arm C vs. A: HR=0.19, p<0.001), and in those with NYHA I-II (Arm B vs. A: HR=0.23, p<0.001; Arm C vs. A: HR=0.27, p<0.001). Conclusion: Patients with more advanced HF have a greater risk of inappropriate ICDtherapy, particularly ATP related to supraventricular arrhythmias with heart rates < 200 bpm. Nevertheless, novel ICD programming with either a high-rate cut-off or delayed detection reduces the risk of inappropriate ICDtherapy in patients with both mild and advanced heartfailure.