Randomised, siteless study to compare systematic atrial fibrillation screening using enrichment by a risk prediction model with standard care in a Swedish population aged ≥ 65 years: CONSIDERING-AF study design.

INTRODUCTION: Atrial fibrillation (AF) is the most common arrhythmia and confers an increased risk of mortality, stroke, heart failure and cognitive decline. There is growing interest in AF screening; however, the most suitable population and device for AF detection remains to be elucidated. Here, we present the design of the CONSIDERING-AF (deteCtiON and Stroke preventIon by moDEl scRreenING for Atrial Fibrillation) study. METHODS AND ANALYSIS: CONSIDERING-AF is a randomised, controlled, siteless, non-blinded diagnostic superiority trial with four parallel groups and a primary endpoint of identifying AF during a 6-month study period set in Region Halland, Sweden. In each group, 740 individuals aged≥65 years will be included. The primary objective is to compare the intervention of AF screening enrichment using a risk prediction model (RPM), followed by 14 days of a continuous ECG patch, with no intervention (standard care). Primary outcome is defined as the incident AF recorded in the Region Halland Information Database after 6 months as compared with standard care. Secondary endpoints include the difference in incident AF between groups enriched or not by the RPM, with and without an invitation to 14 days of continuous ECG recording, and the proportions of oral anticoagulation treatment in the four groups. ETHICS AND DISSEMINATION: This study has ethical approval from the Swedish Ethical Review Authority. Results will be published in peer-reviewed international journals. TRIAL REGISTRATION NUMBER: NCT05838781.

Immunomodulating Effects Depend on Prolactin Levels in Patients with Hyperprolactinemia.

Prolactin is known to have immune modulatory effects acting through the prolactin receptor, which is present on a variety of immune cells. Certain chemokines contribute to form the type of T helper (Th) preponderance in the immune response. The objective of this work was to assess if hyperprolactinemia not related to pregnancy is associated with changes in circulating levels of chemokines and other immunological markers. In this cross sectional study, 35 patients with hyperprolactinemia (5 men), and 102 healthy blood donors (19 men) were included. Serum levels of Th1- Th2- and Th17-associated chemokines, C-reactive protein, immunoglobulins, and the B cell attracting chemokine CXCL13 were assessed. The hyperprolactinemic group had significantly higher levels of Th2 associated CCL22 (p=0.022), Th17 associated CXCL1 (p=0.001), B cell attracting CXCL13 (p=0.003), and C-reactive protein (p<0.001) compared to controls, and these proteins were also positively correlated with prolactin levels. While differences in CCL22, CXCL1, CXCL13, and C-reactive protein were present in patients with low or moderate hyperprolactinemia, no differences were observed at high (>3600 mU/l) prolactin levels. To evaluate a possible dose-associated response to prolactin, an in vitro model was used, showing prolactin-induced increase in T-helper cell activation at moderate levels, while activation decreased at higher levels. Hyperprolactinemia seems to have several immunomodulatory effects and was associated with increased levels of chemokines associated with Th2 and Th17 responses and B cell attraction. However, patients with greatly increased prolactin had normal levels of chemokines, and in vitro, high levels of prolactin decreased T-helper cell activation.

Rapid and sensitive method for the analysis of carbon monoxide in blood using gas chromatography with flame ionisation detection.

In order to measure changes in physiological CO concentrations in blood with good accuracy, a method was developed using gas chromatography with flame ionisation detection (250 degrees C). A nickel catalyst system was fitted to convert CO to methane at 375 degrees C after separation with a molecular sieve column at 35 degrees C. Helium was used as carrier at 30 ml/min. Porcine or human blood (400 microl) was sampled in gastight tubes and treated with sulfuric acid and saponin (800 microl). Accuracy was 1.4% and 1.5% (RSD), respectively. Precision was 2.8% (porcine blood). Limit of detection was 0.01 nmol/ml gas and limit of quantification 12 nmol/ml blood. Calibration was made in the interval 12-514 nmol/ml blood (corresponding to 0.1-6% COHb). Samples were stable for at least a month at +4 degrees C. This paper describes a method with high sensitivity and good accuracy, suitable for analysis of low CO concentrations.