Incidence, prevalence, and trajectories of repetitive conduction patterns in human atrial fibrillation

AIMS: Repetitive conduction patterns in atrial fibrillation (AF) may reflect anatomical structures harbouring preferential conduction paths and indicate the presence of stationary sources for AF. Recently, we demonstrated a novel technique to detect repetitive patterns in high-density contact mapping of AF. As a first step towards repetitive pattern mapping to guide AF ablation, we determined the incidence, prevalence, and trajectories of repetitive conduction patterns in epicardial contact mapping of paroxysmal and persistent AF patients. METHODS AND RESULTS: A 256-channel mapping array was used to record epicardial left and right AF electrograms in persistent AF (persAF, n = 9) and paroxysmal AF (pAF, n = 11) patients. Intervals containing repetitive conduction patterns were detected using recurrence plots. Activation movies, preferential conduction direction, and average activation sequence were used to characterize and classify conduction patterns. Repetitive patterns were identified in 33/40 recordings. Repetitive patterns were more prevalent in pAF compared with persAF [pAF: median 59%, inter-quartile range (41-72) vs. persAF: 39% (0-51), P < 0.01], larger [pAF: = 1.54 (1.15-1.96) vs. persAF: 1.16 (0.74-1.56) cm2, P < 0.001), and more stable [normalized preferentiality (0-1) pAF: 0.38 (0.25-0.50) vs. persAF: 0.23 (0-0.33), P < 0.01]. Most repetitive patterns were peripheral waves (87%), often with conduction block (69%), while breakthroughs (9%) and re-entries (2%) occurred less frequently. CONCLUSION: High-density epicardial contact mapping in AF patients reveals frequent repetitive conduction patterns. In persistent AF patients, repetitive patterns were less frequent, smaller, and more variable than in paroxysmal AF patients. Future research should elucidate whether these patterns can help in finding AF ablation targets

Lack of SARS-CoV-2-specific cellular response in critically ill COVID-19 patients despite apparent effective vaccination

International audienceNo abstract availabl

Heparin-induced thrombocytopenia in COVID-19 patients with severe acute respiratory distress syndrome requiring extracorporeal membrane oxygenation: two case reports

International audienceVeno-venous (VV) extracorporeal membrane oxygenation (ECMO) is increasingly used in Coronavirus disease-19 (COVID-19) patients with the most severe forms of acute respiratory distress syndrome (ARDS). Its use is associated with a significant hemostatic challenge, especially in COVID- 19 patients who have been demonstrated to otherwise present a COVID-19-associated coagulopathy. The systematic use of unfractionated heparin therapy to prevent circuit thrombosis is warranted during ECMO support. The clinical presentation and management of heparin-induced thrombocytopenia, which is a rare but life-threatening complication of heparin therapy, has not been described in those patients yet. We report herein two cases of laboratory-confirmed HIT in COVID-19 patients with severe ARDS admitted to our intensive care unit for VV-ECMO support and the successful use of argatroban as an alternative therapy. We also provide a brief literature review of best evidence for managing such patients. The diagnosis and management of HIT is particularly challenging in COVID-19 patients receiving ECMO support. An increased awareness is warranted in those patients who already present a procoagulant state leading to higher rates of thrombotic events which can confuse the issues. Argatroban seems to be an appropriate and safe therapeutic option in COVID-19 patients with HIT while on VV-ECMO

Altered Ex Vivo NLRP3 Inflammasome Activation Is Associated with 28-Day Mortality in Septic Patients

International audienceSepsis is a life-threatening organ dysfunction caused by a dysregulated response to infection. In this context, the aberrant activation of the NLRP3 inflammasome has been documented mostly through the measurement of increased plasmatic concentrations of IL-1β and IL-18. At the cellular level, contradictory results have been published. However, no study has comprehensively monitored NLRP3 inflammasome activation at the basal level and after ex vivo reactivation of whole blood monocytes and neutrophils focusing on ICU patients with bacterial and viral sepsis, including a longitudinal analysis. Thus, we conducted a prospective longitudinal study, examining NLRP3 inflammasome functionality in COVID-19 ICU patients (n = 15) and bacterial septic shock patients (n = 17) during the first week of ICU hospitalization, compared with healthy donors. Using two whole-blood flow cytometry assays, we detected ASC speck-positive monocytes (i.e., monocytes presenting the polymerization of ASC proteins) and activated caspase-1 in polymorphonuclear cells as read-outs, both at baseline and following nigericin stimulation, a drug that forms pores and activates the NLRP3 inflammasome. Our findings showed that, at baseline and regardless of the type of infection, patients exhibited reduced ASC speck-positive monocytes and decreased activated caspase-1 in PMN compared to healthy volunteers. This decrease was prominent at day 0. Following nigericin stimulation, this reduction was also observed and persisted throughout the first week of hospitalization, irrespective of the cellular population or parameter being considered. Notably, at day 0, this diminished activation and response to stimulation of NLRP3 was associated with a higher 28-day mortality rate. Consequently, our observations highlighted a concurrent decline in both basal expression and ex vivo activation of the NLRP3 inflammasome in circulating myeloid cells from patients with bacterial and viral sepsis in association with increased mortality

Persistently Elevated Soluble Triggering Receptor Expressed on Myeloid Cells 1 and Decreased Monocyte Human Leucocyte Antigen DR Expression Are Associated With Nosocomial Infections in Septic Shock Patients

International audienceSepsis-acquired immunosuppression may play a major role in patients' prognosis through increased risk of secondary infections. Triggering receptor expressed on myeloid cells 1 (TREM-1) is an innate immune receptor involved in cellular activation. Its soluble form (sTREM-1) has been described as a robust marker of mortality in sepsis. The objective of this study was to evaluate its association with the occurrence of nosocomial infections alone or in combination with human leucocyte antigen-DR on monocytes (mHLA-DR). DESIGN: Observational study. SETTING: University Hospital in France. PATIENTS: One hundred sixteen adult septic shock patients as a post hoc study from the IMMUNOSEPSIS cohort (NCT04067674). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma sTREM-1 and monocyte HLA-DR were measured at day 1 or 2 (D1/D2), D3/D4, and D6/D8 after admission. Associations with nosocomial infection were evaluated through multivariable analyses. At D6/D8, both markers were combined, and association with increased risk of nosocomial infection was evaluated in the subgroup of patients with most deregulated markers in a multivariable analysis with death as a competing risk. Significantly decreased mHLA-DR at D6/D8 and increased sTREM-1 concentrations were measured at all time points in nonsurvivors compared with survivors. Decreased mHLA-DR at D6/D8 was significantly associated with increased risk of secondary infections after adjustment for clinical parameters with a subdistribution hazard ratio of 3.61 (95% CI, 1.39-9.34; p = 0.008). At D6/D8, patients with persistently high sTREM-1 and decreased mHLA-DR presented with a significantly increased risk of infection (60%) compared with other patients (15.7%). This association remained significant in the multivariable model (subdistribution hazard ratio [95% CI], 4.65 [1.98-10.9]; p < 0.001). CONCLUSIONS: In addition to its prognostic interest on mortality, sTREM-1, when combined with mHLA-DR, may help to better identify immunosuppressed patients at risk of nosocomial infections

Venous or Arterial Thromboses after Venoarterial-Extracorporeal Membrane Oxygenation Support: Frequency and Risk Factors

International audienceBACKGROUNDAlthough venous thrombosis after venovenous–extracorporeal membrane oxygenation (ECMO) is well described, vascular complications occurring after venoarterial ECMO (VA-ECMO) removal have not yet been thoroughly described. Our aim was to evaluate the frequency of vascular (arterial and venous) complications after VA-ECMO removal and try to identify the risk factors associated with them.METHODSRetrospective analysis of data prospectively collected in 2 intensive care units was performed. Consecutive patients successfully weaned off VA-ECMO during year 1 were screened for cannula-associated deep vein thrombosis (CaDVT) or arterial complications (arterial thrombosis/stenosis) using Doppler ultrasonography.RESULTSFrom November 2018 to November 2019, a total of 107 patients with a median (interquartile range [IQR]) age of 54 (42–63) years and a median (IQR) ECMO support duration of 8 (2–5) days were successfully weaned off VA-ECMO and included. CaDVT occurred in 44 patients (41%), and arterial complications occurred in 15 (14%) (9 acute leg ischemia, 1 arteriovenous femoral fistula, and 5 late femoral stenosis). Multivariable analysis retained longer duration of ECMO support (odds ratio [OR]: 1.12 per day; 95% CI: 1.02–1.22) and infection occurring on ECMO (OR: 3.03; 95% CI: 1.14–8.03) as independent risk factors for CaDVT, whereas older age (OR: 0.97 per year; 95% CI: 0.94–0.99) and previous anti-coagulation use (OR: 0.21; 95% CI: 0.06–0.68) were protective factors for CaDVT. No risk factors for arterial complications were identified.CONCLUSIONSIn patients requiring VA-ECMO support, vascular complications occurred frequently after its removal, especially CaDVT. Arterial complications, either early leg ischemia or late arterial stenosis, were observed less often. Strategies aimed at preventing CaDVT after VA-ECMO remain to be determined

Concomitant Assessment of Monocyte HLA-DR Expression and Ex Vivo TNF-&alpha; Release as Markers of Adverse Outcome after Various Injuries&mdash;Insights from the REALISM Study

Intensive care unit (ICU) patients develop an altered host immune response after severe injuries. This response may evolve towards a state of persistent immunosuppression that is associated with adverse clinical outcomes. The expression of human leukocyte antigen DR on circulating monocytes (mHLA-DR) and ex vivo release of tumor necrosis factor &alpha; (TNF-&alpha;) by lipopolysaccharide-stimulated whole blood are two related biomarkers offered to characterize this phenomenon. The purpose of this study was to concomitantly evaluate the association between mHLA-DR and TNF-&alpha; release and adverse clinical outcome (i.e., death or secondary infection) after severe trauma, sepsis or surgery in a cohort of 353 ICU patients. mHLA-DR and TNF-&alpha; release was similarly and significantly reduced in patients whatever the type of injury. Persistent decreases in both markers at days 5&ndash;7 (post-admission) were significantly associated with adverse outcomes. Overall, mHLA-DR (measured by flow cytometry) appears to be a more robust and standardized parameter. Each marker can be used individually as a surrogate of immunosuppression, depending on center facilities. Combining these two parameters could be of interest to identify the most immunosuppressed patients presenting with a high risk of worsening. This last aspect deserves further exploration

Antibiotic definitive treatment in ventilator associated pneumonia caused by AmpC-producing Enterobacterales in critically ill patients: a prospective multicenter observational study

International audienceBackground: Ventilator associated pneumonia (VAP) due to wild-type AmpC-producing Enterobacterales (wtAE) is frequent in intensive care unit (ICU) patients. Despite a low level of evidence, definitive antimicrobial therapy (AMT) with third generation cephalosporins (3GCs) or piperacillin is discouraged. Methods: Observational prospective study including consecutive wtAE VAP patients in 20 French ICUs. The primary objective was to assess the association of the choice of definitive AMT, i.e. piperacillin ± tazobactam (PTZ), 3GCs or other molecule (4GCs, carbapenems, quinolones, cotrimoxazole; control group), with treatment success at day-7. Recurrence of infection was collected as a secondary outcome, and analyzed accounting for the competing risk of death. Results: From February 2021 to June 2022, 274 patients were included. Enterobacter cloacae was the most prevalent specie (31%). Seventy-eight patients (28%) had PTZ as definitive AMT while 44 (16%) had 3GCs and 152 (56%) were classified in the control group. Day-7 success rate was similar between the 3 groups (74% vs. 73% vs. 68% respectively, p = 0.814). Recurrence probability at day-28 was 31% (95% CI 21–42), 40% (95% CI 26–55) and 21% (95% CI 15–28) for PTZ, 3GCs and control groups ( p = 0.020). In multivariable analysis, choice of definitive AMT was not associated with clinical success, but definitive AMT with 3GCs was associated with recurrence at day-28 [csHR(95%CI) 10.9 (1.92–61.91)]. Conclusion: Choice of definitive antimicrobial therapy was not associated with treatment success at day 7. However, recurrence of pneumonia at day-28 was higher in patients treated with third generation cephalosporins with no differences in mortality or mechanical ventilation duration