Initial heart rate score predicts new-onset atrial tachyarrhythmias in pacemaker patients

Figures

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  Figure 1. Example of HRSc. The HRSc was defined as the per cent of all paced and sensed atrial event in a single most populated 10 b.p.m. rate histogram bin. This figure shows an example of HRSc of patients in DDD mode. Here, HRSc is calculated as 74%. DDD, non-rate–responsive pacing; HRSc, heart rate score.

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  Figure 2. Optimal HRSc for predicting ATAs. J-statistic analysis shows 60–70% as the optimal HRSc for predicting device-determined ATAs, depending on the definition of ATAs. Therefore, the primary optimal cut-point range for HRSc grouping was 60–70%. ATAs, atrial tachyarrhythmias; HRSc, heart rate score.

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  Figure 3. Patient flowchart. A total of 136 980 dual-chamber pacemakers were implanted from 2013 to 2017 in subjects who were on remote monitoring and in the LATITUDE database. The following subjects were excluded: (i) single chamber or biventricular pacemaker implantation, (ii) first LATITUDE transmission >3 months after implantation, (iii) HRSc calculated with <600 000 beats, (iv) device-determined ATAs detection during the first 3 months after implantation, (v) crossover to another programming mode during the first 3 months after implantation, and (vi) programming to non-atrial tracking mode (VVI, VVIR, DDI, DDIR) and lower pacing rate not equal to 60 b.p.m. Subjects from centres opting out of data sharing in a de-identified dataset for research were excluded. As a result, the remaining 34 543 subjects are the subjects for analysis. HRSc, heart rate score; ATAs, atrial tachyarrhythmias; DDD, non-rate–responsive pacing; DDDR, rate-responsive pacing; LRL, lower rate limit; RV, right ventricle.

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  Figure 4. Survival free from ATAs by HRSc. Grouping is shown in this Kaplan–Meier analysis. Kaplan–Meier analysis shows that the incidence of ATAs increased in proportion to every 10% initial HRSc, the primary endpoint. AF, atrial fibrillation; ATAs, atrial tachyarrhythmias; HRSc, heart rate score; RA, right atrium.

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  Figure 5. Results of secondary outcome. By each definition of device-determined ATAs [>5% (A), >10% (B), and >25% (C) of atrial heart beats at more than 170 b.p.m. and also with mode switch episodes lasting >24 h (D)], subjects with >70% in the initial HRSc had significantly increased risk of ATAs compared with subjects with <30% by log-rank test. ATAs, atrial tachyarrhythmias; ATR, atrial tachycardia response; HRSc, heart rate score; RA, right atrium.

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  Figure 6. Heart rate score and RA pacing (correlation by continuous measures). (A) The %RA pacing and initial HRSc were strongly correlated as a whole (Pearson correlation coefficient, r = 90). (B) In the patients with RA pacing ≤20%, the correlation was less relevant between the %RA pacing and initial HRSc (r = 13). (C) In the patients with RA pacing >20%, the correlation was much stronger between the %RA pacing and initial HRSc (r = 84). HRSc, heart rate score; %RA, percentage of right atrium.

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  Figure 7. Free from ATAs by HRSc in patients with low and high cumulative RA pacing per cent. In both groups [RA pacing ≤20% (A) and >20% (B)], subjects with ≥70% in the initial HRSc had significantly increased risk of ATAs compared with the subjects with <70% by log-rank test. ATA, atrial tachyarrhythmia; HRSc, heart rate score; RA, right atrium.