Subclinical atrial fibrillation common in patients with cardiac IEDs: Study

UK: Subclinical atrial fibrillation (SCAF) and resultant higher risk of worst outcomes are frequent among cardiac implantable electronic device (CIED) recipients and are non-linearly associated with age and follow-up time, reports a study published in the European Journal of Internal Medicine.

In recent years, an increase in the use of cardiac implantable electronic devices (CIEDs) as an established treatment for a variety of cardiac arrhythmias has been evident. Cardiac implantable electronic devices include pacemakers, implantable cardioverter defibrillators (ICD), biventricular pacemakers, and cardiac loop recorders.

The increasing use of CIEDs and atrial leads for sensing purposes led to the identification of a clinical entity, the CIED-detected atrial high-rate episodes (AHRE). In recent years, attention to subclinical atrial fibrillation (SCAF), defined as the presence of atrial high-rate episodes (AHREs), in patients with cardiac implantable electronic devices (CIEDs), has gained much interest as a determinant of clinical AF, stroke, and embolism. So far, a highly variable incidence of AHRE/SCAF has been reported, basically depending on patients' clinical characteristics.

Proietti M, University of Liverpool and Liverpool and Liverpool Heart & Chest Hospital, United Kingdom, and colleagues conducted a study to perform a systematic review and meta-regression of the available scientific evidence regarding the epidemiology of SCAF in patients receiving CIEDs.

Researchers searched PubMed and EMBASE for all studies documenting the prevalence of AHREs in patients (n=100 or more, <50% with a history of AF) with CIEDs. Among the 2614 results initially retrieved, 54 studies were included, with a total of 72,784 patients for the present study. The pooled prevalence of SCAF as reported in the original studies was calculated with a generalized linear mixed model (random intercept logistic regression model) using logit transformation of proportions.

Key findings of the study,

• Meta-analysis of the studies showed a pooled prevalence of SCAF of 28.1%, with high heterogeneity between studies (I2=98%).

• A multivariable meta-regression was able to explain a significant proportion of heterogeneity, with age and follow-up time non-linearly, directly, and independently associated with the occurrence of SCAF. 

• Older age, higher CHA2DS2-VASc score, history of AF, hypertension, CHF, and stroke/TIA were all associated with SCAF occurrence.

The authors conclude that SCAF is frequent among CIED recipients and is non-linearly associated with age and follow-up time. Older age, higher thromboembolic risk, and several cardiovascular comorbidities are associated with the presence of SCAF.

Reference:

 Proietti M, Romiti GF, Vitolo M, Borgi M, Rocco AD, Farcomeni A, Miyazawa K, Healey JS, Lane DA, Boriani G, Basili S, Lip GYH. Epidemiology of subclinical atrial fibrillation in patients with cardiac implantable electronic devices: A systematic review and meta-regression. Eur J Intern Med. 2022 Jul 8:S0953-6205(22)00242-4. doi: 10.1016/j.ejim.2022.06.023.