Previous pacemaker therapy was not associated with the risk of clinical events in patients with atrial fibrillation: the Fushimi AF Registry
Authors: Ogawa H , Esato M , Minami K , Ikeda S , Doi K , Hamatani Y , Ide Y , Fujino A , Ishii M , Iguchi M , Masunaga N , Wada H , Hasegawa K , Abe M , Akao M ,   the Fushimi AF Registry
Published: October 2021

Abstract

Background
Patients with atrial fibrillation (AF) occasionally require pacemaker implantation. Meanwhile, patients with implanted pacemaker are occasionally found to have subclinical AF and develop clinical AF. However, little is known about the clinical outcomes of AF patients with implanted pacemaker.

Purpose
We aimed to investigate the clinical outcomes in AF patients undergoing previous pacemaker therapy.

Methods
The Fushimi AF Registry is a community-based prospective survey of the AF patients in a city of Japan. Follow-up data including prescription status were available for 4,447 patients. After exclusion of patients with implantable cardioverter defibrillator and cardiac resynchronization therapy, we investigated 293 AF patients with pacemaker implantation at baseline. We performed propensity score-matching analysis to assess the impact of pacemaker therapy in AF patients.

Results
Of a total cohort, patients with pacemaker were more often female (51.2% vs. 39.7%; p&lt;0.01) and older (78.0 vs. 73.3 years of age; p&lt;0.01). Patients with pacemaker were more likely to have pre-existing heart failure (33.1% vs. 26.6%; p&lt;0.01), valvular heart disease (22.9% vs. 16.8%; p&lt;0.01), chronic kidney disease (48.8% vs. 34.7%; p&lt;0.01), and history of performing direct current cardioversion (7.2% vs. 3.1%; p&lt;0.01), compared with patients without pacemaker. Mean CHA2DS2-VASc score was higher in patients with pacemaker (3.80 vs. 3.34; p&lt;0.01). Patients with pacemaker were more often prescribed oral anticoagulants (62.1% vs. 55.2%; p=0.02), verapamil (13.3% vs. 9.4%; p=0.03), and loop diuretics (30.7% vs. 21.8%; p&lt;0.01). Using propensity score-matching, 291 patients with pacemaker and 291 without pacemaker were matched and baseline characteristics were comparable. The median follow-up period was 1,819 days. All-cause death occurred in 91 patients with pacemaker (6.0 /100 person-years) and 79 patients without pacemaker (5.9 /100 person-years), with a hazard ratio (HR) for patients with pacemaker of 1.01 (95% confidence interval [CI], 0.75 to 1.37; p=0.93). Furthermore, HR of cardiac death for patients with pacemaker was 1.00 (95% CI, 0.23 to 4.32; p=0.99), that of stroke or systemic embolism was 0.69 (95% CI, 0.44 to 1.07; p=0.10) and that of hospitalization for heart failure was 0.94 (95% CI, 0.65 to 1.37; p=0.76).

Conclusion
We identified that patients undergoing previous pacemaker therapy were not associated with the incidence of various adverse clinical events in Japanese AF patients.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim, Bayer Healthcare, Pfizer, Bristol-Myers Squibb, Astellas Pharma, AstraZeneca, Daiichi Sankyo, Novartis Pharma, MSD, Sanofi-Aventis, Takeda Pharmaceutical, and the Practical Research Project for Life-Style related Diseases including Cardiovascular Diseases and Diabetes Mellitus from Japan Agency for Medical Research and Development.