Circulating biomarkers, echocardiographic parameters, and incident subclinical atrial fibrillation in patients with diabetes and hypertension.

BACKGROUND: Long-term rhythm monitoring (LTRM) can detect undiagnosed atrial fibrillation (AF) in patients at high risk of AF and stroke. Biomarkers and echocardiographic parameters could, however, help identify patients benefitting most from LTRM. The aim of this study was to investigate, whether circulating biomarkers of cardiac and vascular function (brain natriuretic peptide (BNP), cardiac troponin I (cTnI), copeptin, and mid-regional proadrenomedullin (MR-proADM)) and echocardiographic parameters were associated with incident subclinical AF (SCAF) in a population at high risk of stroke in the presence of AF. For this purpose, we investigated individuals ≥65 years of age with hypertension and diabetes mellitus, but no history or symptoms of AF or other cardiovascular disease (CVD). METHODS: We included 82 consecutive patients (median age 71.3 years (IQR 67.4-75.1)). All patients received an insertable cardiac monitor (ICM) and were followed for a median of 588 days (IQR 453-712). On the day of ICM implantation, a comprehensive echocardiogram and blood samples were obtained. RESULTS: During a median follow-up of 588 days (IQR: 453-712 days), incident SCAF occurred in 17 patients (20.7%) with a median time to first-detected episode of 91 days (IQR 41-251 days). MR-proADM (median 0.87 nmol/L (IQR 0.76-1.02) vs 0.78 nmol/L (IQR 0.68-0.98)) and copeptin (median 13 pmol/L (IQR 9-17) vs 8 pmol/L (IQR 4-18)) levels were insignificantly higher in patients with incident SCAF. BNP and cTnI concentrations and echocardiographic parameters were similar in the two groups. CONCLUSIONS: MR-proADM, BNP, cTnI, copeptin, and several echocardiographic parameters were not associated with incident SCAF in this cohort of patients with hypertension and diabetes, but without any underlying CVD.

No Detectable Differences in microRNA Plasma Levels between Diabetic Hypertensive Patients with and without Incident Subclinical Atrial Fibrillation.

Background: Long-term rhythm monitoring (LTRM) can detect undiagnosed atrial fibrillation (AF) in patients at risk of AF and stroke. Circulating microRNAs (miRNAs), which have been shown to play a role in atrial electrical and structural remodelling, could help to select patients who would benefit most from LTRM. The aim of this study was to investigate whether patients with diabetes mellitus (DM) and hypertension and screen-detected subclinical AF (SCAF) using an insertable cardiac monitor (ICM) have significantly different plasma baseline levels of five selected miRNAs playing a role in the modulation of atrial electrical and structural remodelling (miR-21-5p, miR-29b-3p, miR-150-5p, miR-328-3p, and miR-432-5p) compared to those without SCAF. Methods: This study was performed at the outpatient clinic of a secondary academic teaching hospital between December 2013 and November 2015. Eligible patients were ≥65 years of age with DM and hypertension but without known heart diseases. All patients received an ICM. On the day of ICM implantation, blood samples for the measurement of plasma levels of the five miRNAs were drawn. In this post hoc analysis, we investigated their expression by reverse transcription-quantitative polymerase chain reaction. MiRNA plasma levels in patients with and without newly detected SCAF were compared. Results: We included 82 consecutive patients (median age of 71.3 years (IQR 67.4-75.1)), who were followed for a median of 588 days (IQR: 453-712 days). Seventeen patients (20.7%) had ICM-detected SCAF. Plasma levels of miR-328-3p, miR-29b-3p, miR-21-5p, miR-432-5p, and miR-150-5p were slightly but not significantly different in patients with incident SCAF compared with patients without. Conclusions: In patients with hypertension and DM, newly detected SCAF was not significantly associated with changes in expression levels of miR-21-5p, miR-29b-3p, miR-150-5p, miR-328-3p, and miR-432-5p.

Detection of Subclinical Atrial Fibrillation in High-Risk Patients Using an Insertable Cardiac Monitor.

OBJECTIVES: The study sought to determine the incidence of subclinical atrial fibrillation (AF) in high-risk patients and to compare the effect of continuous versus intermittent monitoring. BACKGROUND: AF often occurs in a subclinical form, which makes it difficult to detect. The authors do not know the incidence of subclinical AF among patients ≥65 years of age with hypertension and diabetes mellitus. This group of patients has increased risk of developing AF and in addition a high thromboembolic risk, if AF is present. METHODS: A total of 82 outpatients ≥65 years of age (median age 71.3 years [interquartile range [IQR]: 67.4 to 75.1 years]) with hypertension and diabetes mellitus, and no history of AF or any other cardiovascular disease, were consecutively included. All patients received an insertable cardiac monitor (ICM) and were followed for a median of 588 days (IQR: 453 to 712 days). We compared continuous monitoring with 72-h Holter monitoring 1 month after ICM insertion. The primary endpoint was AF ≥2 min for the ICM and AF ≥30 s for the Holter monitoring. RESULTS: During follow-up 17 (20.7%) patients were found to have subclinical AF detected by ICM with a median time to first detected episode of 91 days (IQR: 41 to 251 days) from inclusion. Only 2 (2.4%) patients also had AF episodes on the 72-h Holter monitoring. All detected episodes were completely asymptomatic. CONCLUSIONS: The incidence of subclinical AF in this group of patients was surprisingly high. Continuous monitoring with ICM detected significantly more AF episodes than 72-h Holter monitoring. (Detection of Subclinical Atrial Fibrillation in High Risk Patients Using Implantable Loop Recorder; NCT02041832).