OBJECTIVES:To determine whether preoperative intestinal microbiome characteristics are associated with the development of systemic inflammatory response syndrome (SIRS) after cardiac surgery. DESIGN:Single-center prospective observational cohort study. SETTING:Tertiary university hospital. PARTICIPANTS:A total of 196 adults undergoing elective cardiac surgery with extracorporeal circulation between 2018 and 2019. INTERVENTIONS:No microbiome-targeted intervention was performed. MEASUREMENTS AND MAIN RESULTS:Shotgun metagenomic sequencing was used to assess microbial diversity (inverse Simpson index, gene richness, dominance), taxonomic composition, and functional potential. The primary outcome was development of SIRS within 24 hours postoperatively. Associations were evaluated using Wilcoxon rank-sum tests, χ2 tests, and logistic regression adjusted for age and sex. Forty-four patients (22%) developed SIRS. Microbiome diversity did not differ significantly between patients with and without SIRS (median inverse Simpson index 20.4 v 19.3, p = 0.12; gene richness, p = 0.30; dominance, p = 0.61). In adjusted analyses, diversity was not associated with SIRS risk (odds ratio, 1.04; 95% confidence interval, 0.99-1.07). Descriptive analyses of taxonomic composition and functional potential similarly revealed no significant differences between SIRS and non-SIRS groups. CONCLUSIONS:In this cohort of elective cardiac surgery patients, preoperative gut microbiome diversity, composition, and functional potential were not associated with the development of postoperative SIRS. These findings do not support a strong causal or predictive role of the presurgical gut microbiome in postoperative inflammatory responses after cardiac surgery.
Objectives To evaluate whether early intensive-care-unit (ICU) sedation–ventilation dyssynchrony (SVD) is associated with reintubation and with postoperative complications after cardiac surgery — delirium, postoperative atrial fibrillation, acute kidney injury (AKI), renal replacement therapy, and 30-day mortality — and to explore what proportion of the SVD–AKI association is compatible with mediation by reintubation. Design Retrospective single-center cohort study with inverse-probability-of-treatment weighting (IPTW), Fine–Gray competing-risk regression, multiple imputation, and exploratory counterfactual mediation analysis. Setting Cardiac surgical ICU of a tertiary referral hospital, January 2021 to December 2025. Participants 3,124 consecutive adult patients undergoing cardiac surgery and admitted intubated to the ICU. Interventions None (observational). The exposure—SVD—was classified within the first 12 hours of ICU stay using standardized RASS, CAM-ICU, arterial blood gas, and ventilator variables, and stratified into three mutually exclusive phenotypes: SVD-Deep only, SVD-Light only, and Both. Measurements and Main Results The primary outcome was reintubation within 72 hours of planned extubation. SVD occurred in 780/3,124 (25.0%); reintubation occurred in 157/3,124 (5.0%). In IPTW-adjusted analyses, SVD was associated with reintubation (adjusted odds ratio [aOR] 3.4, 95% CI 2.5–4.6), noninvasive-ventilation/high-flow nasal-cannula rescue (aOR 2.2), delirium (aOR 2.6), postoperative atrial fibrillation (aOR 2.1), AKI (aOR 2.9), renal replacement therapy (aOR 3.2), and 30-day mortality (aOR 2.4); the Fine–Gray subdistribution hazard ratio for reintubation was 3.1 (2.3–4.3). In an exploratory mediation analysis, an estimated 41% (95% CI 28–54%) of the SVD–AKI association was compatible with mediation through reintubation; the E-value for the primary association was 6.1. Conclusions Early ICU SVD was independently associated with a three-fold higher adjusted risk of reintubation and with consistent increases across organ-specific complications after cardiac surgery. SVD is identifiable with routinely available bedside variables and warrants prospective multicenter validation before clinical implementation.
Objectives To characterize the incidence, predictors and clinical outcomes of vasoplegia following left ventricular assist device (LVAD) implantation. Design Systematic review and study-level meta-analysis. Setting Tertiary care. Participants Patients receiving a continuous-flow LVAD. Interventions No interventions were performed. Measurements and Main Results We searched Medline, Embase, and the Cochrane Library from inception to March 2026 for studies on continuous-flow LVADs reporting vasoplegia as an outcome. The incidence of vasoplegia was estimated as a pooled proportion. Comparative analysis were performed using random-effects meta-analysis by pooling risk ratios with 95% confidence intervals (CIs) for binary endpoints or mean difference, if continuous. Long-term survival was evaluated using Kaplan-Meier-derived time-to-event data with a Cox frailty model to obtain hazards ratio. Risk factors from multivariable regression models were pooled to identify predictors. A two-tailed p-value<0.05 was considered statistically significant. We used R studio for all analyses. We included nine observational studies (n=1,855). Vasoplegia developed in 34.2% of patients (95% CI 26.9-42.4%) and was associated with higher early mortality and major bleeding, as well as worse long-term survival and longer hospital stays. No difference was found in ICU mortality, acute kidney injury, stroke and right heart failure. We identified male sex and higher body mass index as risk factors for vasoplegia, while higher blood pressure was protective. Beta blockers, renin-angiotensin-aldosterone inhibitors, neutrophil-lymphocyte ratio, INTERMACS class I-II, cardiopulmonary bypass time, serum creatinine, diabetes and ischemic cardiomyopathy were not significant predictors. Conclusion Vasoplegia affects approximately one-third of patients following LVAD implantation and is associated with worse post-operative outcomes.
