Non-invasive assessment of left ventricular contractility by myocardial work index in veno-arterial membrane oxygenation patients: rationale and design of the MIX-ECMO multicentre observational study.

Introduction and aims: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an increasingly utilized therapeutic choice in patients with cardiogenic shock, however, high complication rate often counteracts with its beneficial cardiopulmonary effects. The assessment of left ventricular (LV) function in key in the management of this population, however, the most commonly used measures of LV performance are substantially load-dependent. Non-invasive myocardial work is a novel LV functional measure which may overcome this limitation and estimate LV function independent of the significantly altered loading conditions of VA-ECMO therapy. The Usefulness of Myocardial Work IndeX in ExtraCorporeal Membrane Oxygenation Patients (MIX-ECMO) study aims to examine the prognostic role of non-invasive myocardial work in VA-ECMO-supported patients. Methods: The MIX-ECMO is a multicentric, prospective, observational study. We aim to enroll 110 patients 48-72 h after the initiation of VA-ECMO support. The patients will undergo a detailed echocardiographic examination and a central echocardiography core laboratory will quantify conventional LV functional measures and non-invasive myocardial work parameters. The primary endpoint will be failure to wean at 30 days as a composite of cardiovascular mortality, need for long-term mechanical circulatory support or heart transplantation at 30 days, and besides that other secondary objectives will also be investigated. Detailed clinical data will also be collected to compare LV functional measures to parameters with established prognostic role and also to the Survival After Veno-arterial-ECMO (SAVE) score. Conclusions: The MIX-ECMO study will be the first to determine if non-invasive myocardial work has added prognostic value in patients receiving VA-ECMO support.

Assessment of Right Ventricular Mechanics by 3D Transesophageal Echocardiography in the Early Phase of Acute Respiratory Distress Syndrome.

Aim: To compare global and axial right ventricular ejection fraction in ventilated patients for moderate-to-severe acute respiratory distress syndrome (ARDS) secondary to early SARS-CoV-2 pneumonia or to other causes, and in ventilated patients without ARDS used as reference. Methods: Retrospective single-center cross-sectional study including 64 ventilated patients: 21 with ARDS related to SARS-CoV-2 (group 1), 22 with ARDS unrelated to SARS-CoV-2 (group 2), and 21 without ARDS (control group). Real-time three-dimensional transesophageal echocardiography was performed for hemodynamic assessment within 24 h after admission. Contraction pattern of the right ventricle was decomposed along the three anatomically relevant axes. Relative contribution of each spatial axis was evaluated by calculating ejection fraction along each axis divided by the global right ventricular ejection fraction. Results: Global right ventricular ejection fraction was significantly lower in group 2 than in both group 1 and controls [median: 43% (25-75th percentiles: 40-57) vs. 58% (55-62) and 65% (56-68), respectively: p < 0.001]. Longitudinal shortening had a similar relative contribution to global right ventricular ejection fraction in all groups [group 1: 32% (28-39), group 2: 29% (24-40), control group: 31% (28-38), p = 0.6]. Radial shortening was lower in group 2 when compared to both group 1 and controls [45% (40-53) vs. 57% (51-62) and 56% (50-60), respectively: p = 0.005]. The relative contribution of right ventricular shortening along the anteroposterior axis was not statistically different between groups [group 1: 51% (41-55), group 2: 56% (46-63), control group; 56% (50-64), p = 0.076]. Conclusion: During early hemodynamic assessment, the right ventricular systolic function appears more impaired in ARDS unrelated to SARS-CoV-2 when compared to early stage SARS-CoV-2 ARDS. Radial shortening appears more involved than longitudinal and anteroposterior shortening in patients with ARDS unrelated to SARS-CoV-2 and decreased right ventricular ejection fraction.

Right ventricular failure in septic shock: characterization, incidence and impact on fluid responsiveness.

OBJECTIVE: Incidence of right ventricular (RV) failure in septic shock patients is not well known, and tricuspid annular plane systolic excursion (TAPSE) could be of limited value. We report the incidence of RV failure in patients with septic shock, its potential impact on the response to fluids, as well as TAPSE values. DESIGN: Ancillary study of the HEMOPRED prospective multicenter study includes patients under mechanical ventilation with circulatory failure. SETTING: This is a multicenter intensive care unit study PATIENTS: Two hundred and eighty-two patients with septic shock were analyzed. Patients were classified in three groups based on central venous pressure (CVP) and RV size (RV/LV end-diastolic area, EDA). In group 1, patients had no RV dilatation (RV/LVEDA < 0.6). In group 2, patients had RV dilatation (RV/LVEDA ≥ 0.6) with a CVP < 8 mmHg (no venous congestion). RV failure was defined in group 3 by RV dilatation and a CVP ≥ 8 mmHg. Pulse pressure variation (PPV) was systematically recorded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In total, 41% of patients were in group 1, 17% in group 2 and 42% in group 3. A correlation between RV size and CVP was only observed in group 3. Higher RV size was associated with a lower response to passive leg raising for a given PPV. A large overlap of TAPSE values was observed between the 3 groups. 63.5% of patients with RV failure had a normal TAPSE. CONCLUSIONS: RV failure, defined by critical care echocardiography (RV dilatation) and a surrogate of venous congestion (CVP ≥ 8 mmHg), was frequently observed in septic shock patients and negatively associated with response to a fluid challenge despite significant PPV. TAPSE was unable to discriminate patients with or without RV failure.