Detection of Atrial High-Rate Episodes in Patients with Cardiac Implantable Electronic Devices — a Multicenter Experience from Pakistan: A Cross-Sectional Study

Objectives: Atrial high-rate episodes (AHRE) are associated with an increased risk of subclinical atrial fibrillation (SCAF) and can be identified in patients with cardiac implantable electronic devices (CIEDs). This first study from Pakistan aims to determine the incidence of AHREs and the characteristics of a Pakistani cohort with AHREs. Methodology: In this bicentric Cross-sectional study, there were 162 patients of more than 18 years with CIEDs presenting to the device clinics were enrolled. The AHREs cutoff was predefined and AHREs were documented if they last for >30 seconds. Patients with known atrial fibrillation were excluded. Results: Mean age of the patients was 64.69±11.64 years and men were of 62.3%. AHREs were found in 22 (13.6%) patients out of which 13(8%) lasted more than 5 minutes. Mean AHREs cutoff 182.27±20.93. Mean CHA₂DS₂-VASc score; 3.10±1.47. 54.9% on beta-blockers, and 37% on angiotensin receptor blockers (ARB). Dual-chamber pacemaker (75.3%) and AV block (60.5%) mostly complete AV block , were the most common CIED and indication for an implant respectively. 43.8% had mildly dilated LA, only 1.2 % had severe mitral stenosis, and 3.1% had severe mitral regurgitation. Multivariable binary logistic regression analysis showed that patients on ARB had fewer episodes of AHREs (OR=0.2, 95% CI= 0.05 -0.8, P-value =0.023) while positive family history for coronary artery disease (CAD) was associated with more episodes (OR=5.62, 95% CI=1.58 -20, P-value =0.008). Conclusion: The incidence of AHREs was considerably lower in our population on CIEDs interrogation as compared to prior studies, although the CHA₂DS₂-VASc score is higher. ARB use and positive family history of CAD had a statistically significant association with AHRE occurrence.