Role of the monocyte-to-high-density lipoprotein ratio in predicting atrial high-rate episodes detected by cardiac implantable electronic devices

Objective: Technological advances have allowed cardiac implantable electronic devices (CIEDs) to detect, analyze, and store atrial high-rate episodes (AHREs), which are surrogate for the term silent atrial fibrillation (AF). The association of AHREs with adverse clinical events has been demonstrated in several recent studies, implying that morbidity and mortality can be significantly prevented by prompt recognition and intervention. Inflammation and oxidative stress are among several mechanisms that contribute to the pathogenesis of AF. The monocyte-to-high-density lipoprotein ratio (M/H ratio) is a novel indicator of both inflammation and oxidative stress. In this study, we aimed to investigate the value of the M/H ratio for predicting AHREs detected by CIEDs.

Methods: A total of 203 patients (mean age: 57.5+9.1 years, 60.1% male) implanted with a dual pacemaker because of sick sinus syndrome were included. Blood samples were obtained from the patients after 12 h of fasting for the analysis of routine biochemistry tests and the lipid panel in the morning of device implantation. At a clinical visit 6 months after CIED implantation, the devices were interrogated to detect the occurrence of AHREs. AHREs were defined as atrial episodes faster than 220 bpm and lasting longer than 5 min. The patients were divided into two groups depending on the presence of AHREs during pacemaker interrogation: Group 1 (AHRE present) and Group 2 (AHRE absent).

Results: At the clinical visit 6 months after CIED implantation, 51 (25.1%) patients had at least one AHRE. The M/H ratio was significantly higher in patients in Group 1 (11.41±1.24) than in those in Group 2 (8.17±1.02) (p<0.01). On performing multivariate Cox regression analysis, the M/H ratio was found to be associated with the occurrence of AHREs in patients with CIEDs (OR: 22.813, 95% CI: 6.852-75.953, p<0.01).

Conclusion: The M/H ratio is an indicator of inflammation and oxidative stress, both of which play an important role in the pathogenesis of AF. This ratio was found to be statically higher in patients with AHREs detected by CIEDs than in those without AHREs.