The efficacy and safety of intrinsic antitachycardia pacing

Abstract

Background: The clinical outcomes of a novel antitachycardia pacing (ATP) algorithm-intrinsic ATP (iATP)-compared to conventional ATP (cATP) have yet to be fully elucidated.

Methods: This retrospective study analyzed 128 patients and 1962 ventricular tachycardia (VT) episodes treated with the iATP or the cATP at Kokura Memorial Hospital. Patients were categorized into two groups: the iATP group (23 patients, 182 episodes) and the cATP group (105 patients, 1780 episodes). We evaluated ATP success rates and baseline patient characteristics on a per-patient basis. Additionally, we extracted VT that were not terminated by a single ATP and compared ATP success rates using propensity score matching.

Results: Per patient; The iATP group exhibited significantly lower creatinine levels (1.18 ± 0.40 mg/dL vs. 1.82 ± 1.61 mg/dL, p = .021) and a shorter follow-up period (609 ± 323 days vs. 1017 ± 252 days, p < .001) compared to the cATP group. ATP success was observed in 19 patients in the iATP group and 62 patients in the cATP group (82.6% vs. 59%, p = .054). Per episode; there was no significant difference in ATP success rate (91.8% vs. 92.7%, p = .645) or in acceleration rate (1.1% vs. 2.4%, p = .274). However, when limited to episodes in which VT was not terminated by a single ATP and propensity score matching was performed, the iATP showed a higher VT termination rate (84.1% vs. 53.6%, p < .001) and a lower acceleration rate (0% vs. 10.1%, p = .013) than the cATP.

Conclusions: The efficacy and safety of the iATP for VT that was not terminated by the first sequence of ATP was demonstrated.

Keywords: acceleration; implantable cardioverter defibrillator; intrinsic antitachycardia pacing; postpacing interval; ventricular tachycardia.

FIGURE 1

Study flowchart. CRT‐D, cardiac resynchronization therapy‐defibrillator; ICD; implantable cardioverter defibrillator. Other abbreviations as in Table 1. In patients underwent de novo ICD or CRT‐D implantation in our hospital, we analyzed the patients who had appropriate ATP therapy for ventricular arrhythmia between August 2020 and August 2023. A total of 445 alerts for ventricular ATP or shock therapy from ICD or CRT‐D were recorded. Finally, the total 128 patients and 1962 episodes were enrolled.

FIGURE 2

Box plot of VT HR (A) and number of sequence (B) in the iATP group and the cATP group. Abbreviations as in Tables 1 and 2. In the iATP group, the mean VT heart rate was higher (median, 194 bpm vs. 167 bpm, p < .001), and the number of sequences was fewer (mean ± standard deviation, 1.79 ± 1.91 vs. 2.10 ± 1.85, p < .001) than in the cATP group.

FIGURE 3

VT mean HR for each episode of the iATP. Abbreviations as in Tables 1 and 2. Most iATP failure occurred in relatively fast rate VT that was over 200/min (shorter than 300 ms).