Therapeutic options for neurocardiogenic syncope: a meta-analysis of randomised trials with and without blinding.

BACKGROUND: Neurocardiogenic syncope is a common condition with significant associated psychological and physical morbidity. The effectiveness of therapeutic options for neurocardiogenic syncope beyond placebo remains uncertain. METHODS: The primary endpoint was the risk ratio (RR) of spontaneously recurring syncope following any therapeutic intervention. We also examined the effect of blinding on treatment efficacy. We identified all randomised trials which evaluated the effect of any pharmacological, device-based or supportive intervention on patients with a history of syncope. A systematic search was conducted on Medline, Embase, PubMed databases and Cochrane Central Register for Controlled Trials from 1950 to 25 April 2023. Event rates, their RRs and 95% CIs were calculated, and a random-effects meta-analysis was conducted for each intervention. Data analysis was performed in R using RStudio. RESULTS: We identified 47 eligible trials randomising 3518 patients. Blinded trials assessing syncope recurrence were neutral for beta blockers, fludrocortisone and conventional dual-chamber pacing but were favourable for selective serotonin reuptake inhibitors (SSRIs) (RR 0.40, 95% CI 0.26 to 0.63, p<0.001), midodrine (RR 0.70, 95% CI 0.53 to 0.94, p=0.016) and closed-loop stimulation (CLS) pacing (RR 0.15, 95% CI 0.07 to 0.35, p<0.001). Unblinded trials reported significant benefits for all therapy categories other than beta blockers and consistently showed larger benefits than blinded trials. CONCLUSIONS: Under blinded conditions, SSRIs, midodrine and CLS pacing significantly reduced syncope recurrence. Future trials for syncope should be blinded to avoid overestimating treatment effects. PROSPERO REGISTRATION NUMBER: CRD42022330148.

Autoimmunity in Long Covid and POTS.

Orthostatic intolerance and other autonomic dysfunction syndromes are emerging as distinct symptom clusters in Long Covid. Often accompanying these are common, multi-system constitutional features such as fatigue, malaise and skin rashes which can signify generalized immune dysregulation. At the same time, multiple autoantibodies are identified in both Covid-related autonomic disorders and non-Covid autonomic disorders, implying a possible underlying autoimmune pathology. The lack of specificity of these findings precludes direct interpretations of cause and association, but their prevalence with its supporting evidence is compelling.

The Effect of 'On-Line' POCT on Patient waiting times in an Accident and Emergency Department.

This POCT (point of care testing) team was constructed at the start of 2012 to implement the POCT project aiming to define and test the hypothesis that interfacing POCT devices to a clinical electronic order communications system reduces patient waiting times in an NHS Accident and Emergency Department (A&E). The devices selected for evaluation initially comprised the Sysmex XS 1000i haematology analyser and the Abbott i-Stat chemistry analyser. The POCT devices were interfaced to a server (Midlynx) which in turn was connected via the hospital internal network, to the ICE system (Integrated Clinical Environment). Test orders entered on the ICE system produced a bar code label read by the individual POCT devices. Once required tests were assayed, the results were transmitted back to the ICE system, where they could be viewed by users across the hospital site. The quality of POCT analytical performance was assessed by running quality control checks as recommended by the manufacturers and by exchanging samples daily with the clinical laboratory. The I-Stat (a Chemistry analyser manufactured by 'Abbott plc') was also tested against material obtained from a national external quality assurance scheme (NEQAS). The time taken to produce POCT tests was calculated as the time elapsed (TE) between requesting tests, and the time at which completed results were returned to the ICE system. Patient waiting times were derived from the patient administration system (Symphony) used in the A&E department. To assess the true effect of POCT on patient waiting times the analysis was confined to cases associated with POCT tests only (n = 217). A control population (n=229) was randomly selected from the clinical laboratory database. The time interval between requesting a test and receiving the results for the POCT tests was 23 minutes and for the laboratory tests, 60 minutes. The patient waiting times (time of discharge - time of arrival) was 167 minutes for the POCT group and 208 for the clinical laboratory group, a difference of 31 minutes. The project confirmed that interfaced (on-line) POCT has many advantages with respect to the quality and safety of data management. The benefits include reliable identification of the requesting clinician and patient and the assurance that the right result is allocated to the right patient. The study also showed that the quality of results produced by the POCT devices met the requirements of the clinical environment.