Prospective Randomized Multicenter Trial of Empirical Antitachycardia Pacing Versus Shocks for Spontaneous Rapid Ventricular Tachycardia in Patients With Implantable Cardioverter-Defibrillators

Abstract

Background-Successful antitachycardia pacing (ATP) terminates ventricular tachycardia (VT) up to 250 bpm without the need for painful shocks in implantable cardioverter-defibrillator (ICD) patients. Fast VT (FVT) Ͼ200 bpm is often treated by shock because of safety concerns, however. This prospective, randomized, multicenter trial compares the safety and utility of empirical ATP with shocks for FVT in a broad ICD population. Methods and Results-We randomized 634 ICD patients to 2 arms-standardized empirical ATP (nϭ313) or shock (nϭ321)-for initial therapy of spontaneous FVT. ICDs were programmed to detect FVT when 18 of 24 intervals were 188 to 250 bpm and 0 of the last 8 intervals were Ͼ250 bpm. Initial FVT therapy was ATP (8 pulses, 88% of FVT cycle length) or shock at 10 J above the defibrillation threshold. Syncope and arrhythmic symptoms were collected through patient diaries and interviews. In 11Ϯ3 months of follow-up, 431 episodes of FVT occurred in 98 patients, representing 32% of ventricular tachyarrhythmias and 76% of those that would be detected as ventricular fibrillation and shocked with traditional ICD programming. ATP was effective in 229 of 284 episodes in the ATP arm (81%, 72% adjusted). Acceleration, episode duration, syncope, and sudden death were similar between arms. Quality of life, measured with the SF-36, improved in patients with FVT in both arms but more so in the ATP arm. Conclusions-Compared with shocks, empirical ATP for FVT is highly effective, is equally safe, and improves quality of life. ATP may be the preferred FVT therapy in most ICD patients.

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

“…Until recently, default device programming used short-duration "detection" criteria that varied by manufacturer and a tachycardia rate of approximately 2.8 to 5 seconds before either ATP or charging (including detection time plus duration or number of intervals) [82,93]. With increased awareness of the potential harm from inappropriate shocks and the realization from stored pacemaker EGMs that even long episodes of VT can self-terminate, a strategy of prolonged detection settings has been explored.…”

“…This programming might improve survival [126]. Indeed, several studies have shown that ATP is effective at terminating slow and fast VT with exceedingly low rates of adverse events like syncope [93,135,[161][162][163][164][165]. The initial bias of the ICD community was to reserve ATP therapy for those patients in whom the therapy was demonstrated to be effective, usually during an electrophysiologic study.…”

“…It is not reflective of the arrhythmias experienced outside the electrophysiology laboratory for primary and secondary prevention patients with ischemic and nonischemic substrates [101,166]. Although the ideal number of ATP bursts has not been definitively determined, current data support the use of up to 2 ATP attempts, given additional attempts yield very little additional efficacy [93,135,[161][162][163][164][165]167,168]. In one study, up to 5 attempts were found to be safe [168].…”

“…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].…”

“…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]. 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.…”