Biomarkers for predicting atrial fibrillation: An explorative sub-analysis of the randomised SCREEN-AF trial.

BACKGROUND: Atrial fibrillation (AF) is a common treatable risk factor for stroke. Screening for paroxysmal AF in general practice is difficult, but biomarkers might help improve screening strategies. OBJECTIVES: We investigated six blood biomarkers for predicting paroxysmal AF in general practice. METHODS: This was a pre-specified sub-study of the SCREEN-AF RCT done in Germany. Between 12/2017-03/2019, we enrolled ambulatory individuals aged 75 years or older with a history of hypertension but without known AF. Participants in the intervention group received active AF screening with a wearable patch, continuous ECG monitoring for 2x2 weeks and usual care in the control group. The primary endpoint was ECG-confirmed AF within six months after randomisation. High-sensitive Troponin I (hsTnI), brain natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-pro BNP), N-terminal pro atrial natriuretic peptide (NT-ANP), mid-regional pro atrial natriuretic peptide (MR-pro ANP) and C-reactive protein (CRP) plasma levels were investigated at randomisation for predicting AF within six months after randomisation. RESULTS: Blood samples were available for 291 of 301 (96.7%) participants, including 8 with AF (3%). Five biomarkers showed higher median results in AF-patients: BNP 78 vs. 41 ng/L (p = 0.012), NT-pro BNP 273 vs. 186 ng/L (p = 0.029), NT-proANP 4.4 vs. 3.5 nmol/L (p = 0.027), MR-pro ANP 164 vs. 125 pmol/L (p = 0.016) and hsTnI 7.4 vs. 3.9 ng/L (p = 0.012). CRP levels were not different between groups (2.8 vs 1.9 mg/L, p = 0.1706). CONCLUSION: Natriuretic peptide levels and hsTnI are higher in patients with AF than without and may help select patients for AF screening, but larger trials are needed.

BNP, NT-pro BNP, NT-ANP and MR-pro ANP and hsTnI levels are higher in patients with AF than without AFWith a sensitivity at 100%, BNP had the highest specificity of 60% (BNP level 50.1ng/L), followed by NT-pro BNP with a specificity of 53% (179ng/l).

The impact of inaccurate assumptions about antibody test accuracy on the parametrisation and results of infectious disease models of epidemics.

The parametrisation of infectious disease models is often done based on epidemiological studies that use diagnostic and serology tests to establish disease prevalence or seroprevalence in the population being modelled. During outbreaks of an emerging infectious disease, tests are often used, both for disease control and epidemiological studies, before studies evaluating their accuracy in the population have concluded, with assumptions made about accuracy parameters like sensitivity and specificity. In this simulation study, we simulated such an outbreak, based on the case study of COVID-19, and found that inaccurate parametrisation of infectious disease models due to assumptions about antibody test accuracy in a seroprevalence study can cause modelling results that inform public health decisions to be inaccurate; for example, in our simulation setup, assuming that antibody test specificity was 0.99 instead of 0.90 when it was in fact 0.90 led to an average relative difference of 0.78 in model-projected peak hospitalisations, even when test sensitivity and all other parameters were accurately characterised. We therefore suggest that methods to speed up test evaluation studies are vitally important in the public health response to an emerging outbreak.

The impact of a standardized Enhanced Recovery After Surgery (ERAS) protocol in patients undergoing minimally invasive heart valve surgery.

BACKGROUND: An enhanced recovery after surgery (ERAS) protocol is a multimodal and multi-professional strategy aiming to accelerate postoperative convalescence. Pre-, intra- and postoperative measures might furthermore reduce postoperative complications and hospital length of stay (LOS) in a cost-effective way. We hypothesized that our unique ERAS protocol leads to shorter stays on the intensive care unit (ICU) and a quicker discharge without compromising patient safety. METHODS: This retrospective single center cohort study compares data of n = 101 patients undergoing minimally invasive heart valve surgery receiving a comprehensive ERAS protocol and n = 111 patients receiving routine care. Hierarchically ordered primary endpoints are postoperative hospital length of stay (LOS), postoperative complications and ICU LOS. RESULTS: Patients risk profiles and disease characteristics were comparably similar. Age was relevantly different between the groups (56 (17) vs. 57.5 (13) years, p = 0.015) and therefore adjusted. Postoperative LOS was significantly lower in ERAS group (6 (2) days vs. 7 (1) days, p<0.01). No significant differences, neither in intra- or postoperative complications, nor in the number of readmissions (15.8% vs. 9.9%, p = 0.196) were shown. In hospital LOS (7 (3) days vs. 8 (4) days, p<0.01) and ICU LOS (18.5 (6) hours vs. 26.5 (29) hours, p<0.01) a considerable difference was shown. CONCLUSION: The ERAS protocol for minimally invasive heart valve surgery is safe and feasible in an elective setting and leads to a quicker hospital discharge without compromising patient safety. However, further investigation in a randomized setting is needed.