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

Aims: Heart rate score (HRSc), the per cent of atrial paced and sensed event in the largest 10 b.p.m. rate histogram bin of a pacemaker, predicts survival in patients with cardiac devices. No correlation between HRSc and development of atrial fibrillation (AF) has been reported. In this study, we evaluated the relationship between pacemaker post-implantation HRSc and the incidence of newly developed atrial tachyarrhythmias (ATAs).

Methods and results: Patients with dual-chamber pacemakers, implanted 2013-17, with the LATITUDE remote monitoring data with ≥600 000 beats of histogram data collected at baseline were included (N = 34 543). Heart rate score was determined from the initial 3-month post-implantation histogram data. Patients were excluded if they had ATAs, defined as atrial high-rate episodes >5 min or >1% of right atrial beats >170 b.p.m. during the initial 3 months post-implantation. New ATAs, after the baseline period, were defined by each of the following: >1, >10, or >25% of atrial beats >170 b.p.m. or atrial tachycardia response (ATR) events >24 h. Patients were followed a median of 2.8 (1.0-4.0) years. The incidence of ATAs increased in proportion to HRSc (log-rank P-value <0.001), and the initial HRSc ≥70% was associated with increased ATAs by all definitions. Patients with initial HRSc ≥70% were older, had a higher percentage of right atrium pacing (%RA pacing), had a lower percentage of right ventricular pacing (%RV pacing), and were more likely programmed with rate-response vs. subjects with HRSc <70%. Initial HRSc (hazard ratio: 1.07, 95% confidence interval: 1.05-1.09; P < 0.0001) independently predicted ATAs after adjusting for age, gender, %RV pacing, and rate-response programming. The %RA pacing and initial HRSc were correlated.

Conclusion: Heart rate score independently predicts any subsequent duration of ATAs in pacemaker patients.