Abstract Body (Do not enter title and authors here): Background:
As systemic congestion takes center stage in the prognosis of acute heart failure (AHF), the Venous Excess Ultrasound (VExUS) protocol has emerged as a compelling tool for its bedside assessment. However, its prognostic value remains unclear. To address this gap, we performed a systematic review and meta-analysis evaluating whether VExUS can reliably predict in-hospital mortality in patients admitted with AHF.

Research Question:
Can the VExUS protocol reliably predict in-hospital mortality in patients admitted with AHF?

Methods:
We systematically searched PubMed, Embase, and the Cochrane Library for studies evaluating the prognostic value of the VExUS protocol in patients with AHF. Bayesian random-effects meta-analysis was yielded for marginal posterior distributions for the overall effect and between-study heterogeneity. We used mean and 95% credible intervals (CrI) to describe these distributions, defined as the narrowest interval containing 95% of the probability density function. Our primary estimands are expressed as odds ratio (OR), and also focused on the calculation of posterior probabilities. Statistical analyses were performed with R version 4.5.0.

Results:
Five studies, comprising 565 patients, were included in the analysis. Mean ejection fraction ranged from 32% to 54%. Figure 1A contains the forest plot of the in-hospital mortality outcome. The average odds ratio was 0.12 (95% CrI: 0.04, 0.32). The posterior probability indicating any level of certainty regarding the score (OR<1) was 99.99%, while the probability of a clinically meaningful level of certainty (OR<0.8) was 99.97%. In terms of predictive distribution, we determined a 95% probability that the true odds ratio in a future study would fall within the range of 0.03 to 0.41 (as shown in Figure 1), with a 99.76% likelihood that it would be less than 1.0. Sensitivity analyses showed that overall effect results were not heavily influenced by different priors (Figure 1B). Figure 2 shows the posterior distribution of the overall effect and posterior probabilities related to any odds ratio cutoff.

Conclusions:
This systematic review and meta-analysis suggests that a VExUS grade greater than 2 is associated with increased in-hospital mortality in patients with AHF. These findings support the potential role of VExUS as a prognostic tool for risk stratification in this population, warranting further investigation in larger, prospective studies.