P5431The relationship between pulse rate and the risk of cardiac events in patients with atrial fibrillation: the Fushimi AF registry
Authors: Iguchi M , Masunaga N , Ishii M , An Y , Esato M , Wada H , Hasegawa K , Ogawa H , Abe M , Akao M 
Published: October 2019

Abstract

Background
Relationship between pulse rate (PR) and cardiac events in patients with sustained (persistent and permanent) atrial fibrillation (AF) in routine clinical practice remains unclear.

Methods
The Fushimi AF Registry is a community-based prospective survey of the AF patients in Fushimi-ku, Kyoto. Follow-up data were available for 4,454 patients, and we obtained PR at baseline in 2,209 patients of 2,248 sustained AF patients. We divided these patients into four groups based on their PR; G1 (PR≥100 bpm, n=249), G2 (80 bpm≤PR<100 bpm, n=821), G3 (60 bpm≤PR<80 bpm, n=986), and G4 (PR<60 bpm, n=153), and examined the relationship between PR and cardiac events (composite of cardiovascular death and hospitalization for heart failure (HF)).

Results
Proportion of female and symptomatic AF were more in G1 group, and diastolic blood pressure was higher in G1 group, despite that systolic blood pressure was similar between the four groups. Prevalence of anemia was higher in G1 group, and that of chronic kidney disease was higher in G4 group. Prevalence of HF and left ventricular dysfunction tended to be higher in G1 group but not statistically significant. Beta-blockers and non-dihydropyridine calcium blockers were more often prescribed in G1 group. During the median follow-up of 1,449 days, cardiac events occurred in 399 patients (358 hospitalization for HF and 41 cardiovascular death). In Kaplan-Meier analysis, the incidence of cardiac events were comparable between the four groups (p=0.3). The incidence of all cause death (p=0.06) and stroke or systemic embolism (p=0.4) was also similar between the four groups. The incidence of cardiac events did not differ between the four groups when we divided the patients based on the presence of HF at baseline, and the incidence of cardiac events was also comparable between the four groups after adjusting potential confounders. However, when we examined the impact of PR according to 10 bpm increment, patients with very low PR (<50 bpm) (hazard ratio [95% confidence intervals], 2.22 [1.04–4.15]) and very high PR (≥110 bpm) (hazard ratio [95% confidence intervals], 1.67 [1.00–2.64]) had higher incidence of cardiac events than patients with PR of 70–79 bpm (Figure). Furthermore, we acquired the annual follow-up data of PR. Mean PR during the follow-up periods was not different between patients with cardiac events and those without (with vs without, 79.5±15.3 bpm vs 79.7±12.7 bpm; p=0.8), whereas maximum PR was less in patients with cardiac events (85.2±17.5 bpm vs 89.3±16.2 bpm; p<0.0001). Patients with maximum PR<60 bpm showed higher incidence of cardiac events, and the incidence of cardiac events was the lowest in patients with maximum PR of 80 to 99 bpm (maximum PR<60 bpm: 31.3%, 60–79 bpm: 24.5%, 80–99 bpm: 14.5%, 100 bpm: 16.1%; P<ehz746.03881).

Conclusion
PR did not appear to have strong impact on cardiac events in patients with sustained AF. However, low PR might be a risk for developing cardiac events.

Acknowledgement/Funding
Japan Agency for Medical Research and Development, AMED (15656344, 16768811), Boehringer Ingelheim, Bayer Healthcare, Pfizer, Bristol-Myers Squibb