Comparison of Mixed Venous Oxygen Saturation and Premembranous Venous Oxygen Saturation in Patients on Peripheral Venous-Arterial Extracorporeal Membrane Oxygenation.

In patients on veno-arterial extracorporeal membrane oxygenation (ECMO) premembranous venous oxygen saturation (Spm-vO2) is continuously displayed on the ECMO console. However, the concordance between Spm-vO2 and mixed venous oxygen saturation (SvO2) remains largely unexplored. Our single-center retrospective study included adult patients who had paired SvO2 and Spm-vO2 readings within 15 minutes of each other, on peripherally cannulated Vf ivc-A ECMO and a pulmonary artery using catheter (PAC). The 82 pairs of observations showed a mean difference of 11.37% (95% limits of agreement -6.0 to 28.74, p < 0.001) between Spm-vO2 and SvO2. Although the two values correlated with each other (r = 0.51, p < 0.01), the difference between the paired measurements was larger at lower values of SvO2 (3.72 ± 6.38% when SvO2 >80%, 11.79±7.46% when SvO2 between 60% and 80%, and 18.81±12.09% when SvO2 <60%). The equation SvO2 = 1.2* Spm-vO2 - 28.03 was obtained by Passing Bablok regression. Cardiac index calculated by Spm-vO2 and SvO2 differed by 0.8L/minute/m2 (95% limits of agreement -0.52 to 2.17, p < 0.001). In peripheral VA-ECMO, Spm-vO2 is consistently higher than SvO2, with more discordance at lower saturation levels. Using Spm-vO2 to estimate cardiac output using Fick method yields inaccurate results.

ProtekDuo percutaneous ventricular support system-physiology and clinical applications.

The ProtekDuo (LivaNova, London, UK) cannula is a dual-lumen device, typically inserted into the right internal jugular (IJ) vein through a percutaneous approach, with fluoroscopy or ultrasound guidance. When connected to a pump, such as the TandemHeart (LivaNova, London, UK) or CentriMag (Abbott, Pleasanton, CA, USA), it can function as a right ventricular (RV) mechanical circulatory support (MCS). When an oxygenator is also added [veno-pulmonary (V-P)], it can provide extracorporeal membrane oxygenation (ECMO) support. This review aims to provide a comprehensive overview of the device's physiology and clinical applications. In the setting of RV failure (RVF), the ProtekDuo cannula, with its outflow in the main pulmonary artery (PA), can bypass the failing RV, improving pulmonary flow, left atrial (LA) filling pressures, and left ventricular (LV) preload. This can also reduce ventricular interdependence and leftward shift of the interventricular septum that occurs in RVF. In this review, the key sections expand on the use of the ProtekDuo cannula in the management of critically ill patients, specifically, the use of ProtekDuo for RV myocardial infarction (MI) RVF, LV assist device (LVAD) implantation-associated RVF, RVF post-heart transplantation, temporary biventricular MCS as bridge to recovery (ECpella 2.0 or PROpella), biventricular support as bridge to recovery or decision, isolated LV failure, post lung transplantation (LT) care, and other miscellaneous clinical scenarios. ProtekDuo is an important tool in the armory of RVF management. The ProtekDuo system is expected to gain more popularity given its clear advantages such as groin-free approach allowing for mobility, easy percutaneous deployment, compatibility with various pumps and oxygenators, and the versatility to be integrated in numerous configurations. In an era of expanding MCS options, further research is needed to better understand the optimal tool for specific patient subsets.

Circulating Proteome Analysis Identifies Reduced Inflammation After Initiation of Hemodynamic Support with Either Veno-Arterial Extracorporeal Membrane Oxygenation or Impella in Patients with Cardiogenic Shock.

In-hospital mortality associated with cardiogenic shock (CS) remains high despite the use of percutaneous assist devices. We sought to determine whether support with VA-ECMO or Impella in patients with CS alters specific components of the plasma proteome. Plasma samples were collected before device implantation and 72 h after initiation of support in 11 CS patients receiving ECMO or Impella. SOMAscan was used to detect 1305 circulating proteins. Sixty-seven proteins were changed after ECMO (18 upregulated and 49 downregulated, p < 0.05), 38 after Impella (10 upregulated and 28 downregulated, p < 0.05), and only eight proteins were commonly affected. Despite minimal protein overlap, both devices were associated with markers of reduced inflammation and increased apoptosis of inflammatory cells. In summary, ECMO and Impella are associated with reduced expression of inflammatory markers and increased markers of inflammatory cell death. These circulating proteins may serve as novel targets of therapy or biomarkers to tailor AMCS use.

A rare case of echo enhancing agent anaphylaxis complicated by acute coronary syndrome.

Enhancing agents in echocardiography are used frequently to improve endocardial border visualization and assessment of structural heart disease. We present a unique case of anaphylactic shock with acute coronary syndrome following administration of sulfur hexafluoride echo enhancing agent. This case emphasizes the importance of recognizing anaphylaxis to enhancing agents, as well as recognizing the potential relationship between anaphylaxis and acute coronary syndrome with in-stent thrombosis.

Clinical impact of pulmonary artery catheter in patients with cardiogenic shock: A systematic review and meta-analysis.

BACKGROUND: The clinical utility of the pulmonary artery catheter (PAC) for the management of cardiogenic shock (CS) remains controversial. We performed a systematic review and meta-analysis exploring the association between PAC use and mortality among patients with CS. METHODS: Published studies of patients with CS treated with or without PAC hemodynamic guidance were retrieved from MEDLINE and PubMed databases from January 1, 2000, to December 31, 2021. The primary outcome was mortality, which was defined as a combination of in-hospital mortality and 30-day mortality. Secondary outcomes assessed 30-day and in-hospital mortality separately. To assess the quality of nonrandomized studies, the Newcastle-Ottawa Scale (NOS), a well-established scoring system was used. We analyzed outcomes for each study using NOS with a threshold value of >6, indicating high quality. We also performed analyses based on the countries of the studies conducted. RESULTS: Six studies with a total of 930,530 patients with CS were analyzed. Of these, 85,769 patients were in the PAC-treated group, and 844,761 patients did not receive a PAC. PAC use was associated with a significantly lower risk of mortality (PAC: 4.6 % to 41.5 % vs control: 18.8 % to 51.0 %) (OR 0.63, 95 % CI: 0.41-0.97, I2 = 0.96). Subgroup analyses demonstrated no difference in the risk of mortality between NOS ≥ 6 studies and NOS < 6 studies (p-interaction = 0.57), 30-day and in-hospital mortality (p-interaction = 0.83), or the country of origin of studies (p-interaction = 0.08). CONCLUSIONS: The use of PAC in patients with CS may be associated with decreased mortality. These data support the need for a randomized controlled trial testing the utility of PAC use in CS.

The impact of temporary mechanical circulatory support strategies on thrombocytopenia.

One common but not well-understood phenomenon of temporary mechanical circulatory support (MCS) use is thrombocytopenia. This clinical issue increases the risk of bleeding and the need for platelet transfusion. Additionally, heparin-induced thrombocytopenia must be considered as part of the differential diagnosis, which complicates patient management. In what follows, we analyze the degree and relative rate of platelet count drop with various temporary MCS strategies - Impella 5.5; Veno-venous Extracorporeal Membrane Oxygenation (VV ECMO); Veno-arterial ECMO (VA ECMO); Intra-aortic Balloon Pump (IABP) and Centrimag Biventricular Assist Device (BIVAD). A total of 337 cohort was investigated. 77 was included for analysis after strict exclusion criteria were utilized (platelet transfusions, bleeding complications, etc.). Repeated measure mixed effect and linear regression models were used to assess the percent platelet drop on implantation of MCS and recovery after explantation of MCS. A statistically significant mean percent drop occurred in MCS types - VA ECMO(-69.6%, p < 0.001), VV ECMO(-40.9%, p < 0.001), Impella 5.5(-20.9%, p = 0.01) and IABP(-28.3%, p = 0.01), except Centrimag BIVAD(-6.5%, p = 0.61). Platelet recovery to or above baseline occurred in VA ECMO(+107.0%, p = 0.42), Impella 5.5(+117.2%, p = 0.28), IABP(+108.3%, p = 0.37), VV-ECMO(163.3%, p = 0.01*) and Centrimag BIVAD(+100.1%, p = 0.99). These results show that the degree of thrombocytopenia depends on MCS device type and is reversible.

Outcomes in cardiogenic shock: the role of surrogate endpoints.

PURPOSE OF REVIEW: Early revascularization, invasive hemodynamic profiling, and initiation of temporary mechanical circulatory support (MCS) have all become routine components of cardiogenic shock (CS) management. Despite this evolution in clinical practice, patient selection and timing of treatment initiation remain a significant barrier to achieving sustained improvement in CS outcomes. Recent efforts to standardize CS management, through the development of treatment algorithms, have relied heavily on surrogate endpoints to drive therapeutic decisions. The present review aims to provide an overview of the basis of evidence for those surrogate endpoints commonly employed in clinical trials and CS management algorithms. RECENT FINDINGS: Recent publications from both observational and randomized cohorts have demonstrated the utility of surrogate endpoints in risk stratifying patients with CS. In particular, invasive hemodynamics using pulmonary artery catheters to guide initiation and weaning of MCS, biochemical markers that portend imminent end-organ failure, and clinical risk scores that combine multiple hemodynamic and laboratory parameters have demonstrated an ability to prognosticate outcomes in patients with CS. SUMMARY: Although further validation is necessary, multiple clinical, hemodynamic, and biochemical markers have demonstrated utility as surrogate endpoints in CS, and will undoubtedly assist physicians in clinical decision-making.

Strategies to reduce limb ischemia in peripheral venoarterial extracorporeal membrane oxygenation: A systematic review and Meta-analysis.

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides cardiovascular and respiratory support for patients in cardiogenic shock; yet, complications are a frequent source of morbidity and mortality. Limb ischemia can be potentially mitigated by limp perfusion protection strategies (LPPS). We performed a systematic review and meta-analysis to evaluate the safety and efficacy of two LPPS in patients treated with peripheral VA-ECMO - prophylactic insertion of a distal perfusion catheter (DPC) and small bore (<17 Fr) arterial return cannula. Among 22 included studies, limb ischemia was reduced in patients receiving a small arterial cannula (OR 0.40, 95% CI 0.24-0.65; p < 0.001) and in patients receiving a prophylactic DPC (OR 0.31, 95% CI 0.21-0.47; p < 0.001). Mortality was not significantly reduced with either a small arterial cannula (OR 0.70, 95% CI 0.23-2.18; p = 0.54) or prophylactic DPC strategy (OR 0.89, 95% CI 0.67-1.17; p = 0.40). As such, prophylactic insertion of a DPC or smaller bore arterial return cannula appear to reduce the risk of lower limb ischemia in this analysis. Further data are needed to confirm these findings. Registration: Registered in PROSPERO Database (Registration CRD42020215677).

Left Ventricular Unloading Before Percutaneous Coronary Intervention is Associated With Improved Survival in Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock: A Systematic Review and Meta-Analysis.

BACKGROUND: Left ventricular unloading with Impella may improve survival outcomes in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS). However, the optimal timing to initiate left ventricular unloading has yet to be established. Therefore, we conducted a systematic review and meta-analysis to compare survival in patients with AMI-CS who were supported with Impella prior to PCI (pre-PCI) to those in whom support was initiated following PCI (post-PCI). METHODS: All studies that evaluated the impact of pre-PCI versus post-PCI Impella placement in patients with AMI-CS were included. Primary endpoints included in-hospital, 30-day, and 6-month survival rates. RESULTS: We identified five observational studies comparing outcomes in 432 patients with AMI-CS, of which 173 patients were treated with Impella pre-PCI and 259 patients post-PCI. Patients in the pre-PCI group had lower in-hospital mortality compared to patients in the post-PCI group (RR 0.62, 95% CI: 0.50-0.76, I2 = 0%). The lower mortality rate in the pre-PCI group remained evident at 30 days (HR 0.60, 95% CI: 0.47-0.78, I2 = 0%) and at 6 months (HR 0.66, 95% CI: 0.44-0.97, I2 = 0%). There was no difference in the risk of adverse events including reinfarction, stroke, major bleeding, acute ischemic limb, access site bleeding, and hemolysis. CONCLUSIONS: In this meta-analysis of studies evaluating survival among AMI-CS patients with left ventricular unloading initiated pre- versus post-PCI, Impella placement prior to PCI was associated with improved survival.

Lactate Clearance Is Associated With Improved Survival in Cardiogenic Shock: A Systematic Review and Meta-Analysis of Prognostic Factor Studies.

OBJECTIVE: Elevated blood lactate levels are strongly associated with mortality in patients with cardiogenic shock. Recent evidence suggests that the degree and rate at which blood lactate levels decrease after the initiation of treatment may be equally important in patient prognosis. We performed a systematic review and meta-analysis to evaluate the usefulness of lactate clearance as a prognostic factor in cardiogenic shock. METHODS AND RESULTS: We performed searches of Ovid MEDLINE, Elsevier EMBASE, EBM Reviews-Cochrane Central Register of Controlled Trials, and Web of Science to identify studies comparing lactate clearance between survivors and nonsurvivors at one or more timepoints. Both prospective and retrospective studies were eligible for inclusion. Two study investigators independently screened, extracted data, and assessed the quality of all included studies. Twelve studies were included in the meta-analysis. The median lactate clearance at 6-8 hours was 21.9% (interquartile range [IQR] 14.6%-42.1%) in survivors and 0.6% (IQR -3.7% to 14.6%) in nonsurvivors. At 24 hours, the median lactate clearance was 60.7% (IQR 58.1%-76.3%) and 40.3% (IQR 30.2%-55.8%) in survivors and nonsurvivors, respectively. Accordingly, the pooled mean difference in lactate clearance between survivors and nonsurvivors at 6-8 hours was 17.3% (95% CI 11.6%-23.1%, P < .001) at 6-8 hours and 27.9% (95% CI 14.1%-41.7%, P < .001) at 24 hours. CONCLUSIONS: Survivors had significantly greater lactate clearance at 6-8 hours and at 24 hours compared with nonsurvivors, suggesting that lactate clearance is an important prognostic marker in cardiogenic shock.

Temporary mechanical circulatory support devices: updates from recent studies.

PURPOSE OF REVIEW: Over the past several years, the role of short-term mechanical circulatory support (MCS) devices has become the dominant focus in efforts to improve outcomes in patients with cardiogenic shock (CS). Alongside these efforts, temporary MCS devices have been increasingly used to support patients prior to cardiac surgery, during high-risk percutaneous coronary intervention, awaiting cardiac transplantation, and in the setting of refractory cardiac arrest. The present review aims to provide an update on the recent literature evaluating the evolving role of temporary MCS devices, and to provide insights into the current challenges and future directions of MCS research. RECENT FINDINGS: Recent observational data have demonstrated potential roles for intra-aortic balloon pump preoperatively in high-risk patients awaiting coronary artery bypass grafting, and advanced heart failure patients awaiting transplantation. Impella continues to demonstrate promising results as part of an early MCS strategy in CS, as a temporary bridge to transplantation, and as a mechanism for left ventricular unloading in patients on venoarterial extracorporeal membrane oxygenation (ECMO). Finally, the first randomized trial of ECMO facilitated resuscitation in the United States demonstrated improved survival in patients with refractory out of hospital cardiac arrest. SUMMARY: Though randomized data remains limited, observational data continue to support the role of temporary MCS devices in a variety of clinical settings.

Molecular adsorbent recirculating system as artificial support therapy for liver failure: a meta-analysis.

Molecular Adsorbent Recirculating System (MARS) is an artificial liver support system that has been developed for patients with liver failure until the liver regains function or as a bridge to transplantation. We conducted a meta-analysis to examine the efficacy of this promising therapy. We searched MEDLINE, EMBASE, and the Cochrane Registry of Controlled Trials databases, and abstracts from the proceedings of several scientific meetings. Patients with acute, acute on chronic, and hyperacute liver failure were included and we compared MARS with standard medical therapy. Randomized and nonrandomized controlled trials were included and Molecular Adsorbent Recirculating System was the intervention used. We evaluated net change in total bilirubin levels, improvement in hepatic encephalopathy and mortality. Nine randomized controlled trials and one nonrandomized controlled study met criteria and were included. By meta-analysis, MARS resulted in a significant decrease in total bilirubin levels (net change -7.0 mg/dl; 95% CI -10.4, -3.7; p < 0.001) and in an improvement in the West-Haven grade of hepatic encephalopathy (odds ratio [OR] 3.0; 95% CI 1.9, 5.0; p < 0.001). There was no beneficial effect on mortality (OR 0.91; 95% CI 0.64, 1.31; p = 0.62). The limitations of this study include a small sample size, an inability to blind with significant heterogeneity among studies, and variable definitions of liver failure. The Molecular Adsorbent Recirculating System is associated with a significant improvement in total bilirubin levels and hepatic encephalopathy but has no impact on survival. Large studies are required to assess the merit of this promising therapy on patient-centered outcomes.