ABSTRACT
BACKGROUND: The RAID (Ranolazine Implantable Cardioverter-Defibrillator) randomized placebo-controlled trial showed that ranolazine treatment was associated with reduction in recurrent ventricular tachycardia (VT) requiring appropriate implantable cardioverter-defibrillator (ICD) therapy. OBJECTIVES: This study aimed to identify groups of patients in whom ranolazine treatment would result in the highest reduction of ventricular tachyarrhythmia (VTA) burden. METHODS: Andersen-Gill analyses were performed to identify variables associated with risk for VTA burden among 1,012 patients enrolled in RAID. The primary endpoint was VTA burden defined as VTA episodes requiring appropriate treatment. RESULTS: Multivariate analysis identified 7 factors associated with increased VTA burden: history of VTA, age ≥65 years, New York Heart Association functional class ≥III, QRS complex (≥130 ms), low ejection fraction (<30%), atrial fibrillation (AF), and concomitant antiarrhythmic drug (AAD) therapy. The effect of ranolazine on VTA burden was seen among patients without concomitant AAD therapy (HR [HR]: 0.68; 95% CI: 0.55-0.84; P < 0.001), whereas no effect was seen among those who are concomitantly treated with other AADs (HR: 1.33; 95% CI: 0.90-1.96; P = 0.16); P = 0.003 for interaction. In patients with cardiac resynchronization therapy (CRT) ICDs, ranolazine treatment was associated with a 36% risk reduction for VTA recurrence (HR: 0.64; 95% CI: 0.47-0.86; P < 0.001), whereas among patients with ICDs without CRT no significant effect was noted (HR: 0.94; 95% CI: 0.74-1.18; P = 0.57); P = 0.047 for interaction. CONCLUSIONS: In patients with high risk for VTA, ranolazine is effective in reducing VTA burden, with significantly greater effect in CRT-treated patients, those without AF, and those not treated with concomitant AADs. In patients already on AADs or those with AF, the addition of ranolazine did not affect VTA burden. (Ranolazine Implantable Cardioverter-Defibrillator Trial [RAID]; NCT01215253).
Subject(s)
Defibrillators, Implantable , Ranolazine , Tachycardia, Ventricular , Aged , Humans , Ranolazine/therapeutic use , Tachycardia, Ventricular/prevention & controlSubject(s)
Chewing Gum , Fasting/physiology , Gastric Emptying/physiology , Gastrointestinal Contents/chemistry , Gastrointestinal Contents/diagnostic imaging , Gastroscopy , Adult , Aged , Aged, 80 and over , Female , Gastric Juice/physiology , Gastroscopy/adverse effects , Humans , Incidence , Male , Middle Aged , Postoperative Period , Stomach/diagnostic imaging , Stomach/physiology , Sugars , Treatment OutcomeABSTRACT
AIMS: Selective atrial pacing algorithms have been developed for prevention of atrial tachycardia/atrial fibrillation (AT/AF). Although short-term studies have shown modest to minimal incremental benefit of these algorithms compared with conventional dual-chamber (DDD/R) pacing for prevention of AT/AF, the long-term effects of these algorithms are unknown. Accordingly, we compared atrial antitachycardia pacing (ATP) therapy and combined atrial ATP and atrial pace prevention (ATP + Prevention) algorithms to conventional DDD/R pacing for prevention of AT/AF over long-term follow-up. METHODS AND RESULTS: Seventy-one patients with AT/AF following pacemaker insertion were randomized to DDD/R pacing, DDD/R plus ATP pacing, or DDD/R plus ATP and prevention pacing and followed for 3 years. Atrial tachycardia/AF burden and an AF symptom scale were compared over time between groups. Atrial tachycardia/AF burden remained stable over 3 years in the DDD/R and ATP + Prevention groups. Atrial tachycardia/AF burden increased significantly over time in the ATP group. Patients not on class I or III antiarrhythmic drug therapy were more likely to experience an increase in AT/AF burden over time. CONCLUSION: Atrial ATP and atrial ATP in combination with atrial pace prevention algorithms do not suppress AT/AF over long-term follow-up compared with DDD/R pacing.
