Outcomes after extracorporeal life support for postcardiotomy cardiogenic shock

Identifying and mitigating risk of postcardiotomy cardiogenic shock in patients with ischemic and nonischemic cardiomyopathy

OBJECTIVES

To identify preoperative predictors of postcardiotomy cardiogenic shock in patients with ischemic and nonischemic cardiomyopathy and evaluate trajectory of postoperative ventricular function.

METHODS

From January 2017 to January 2020, 238 patients with ejection fraction <30% (206/238) or 30% to 34% with at least moderately severe mitral regurgitation (32/238) underwent conventional cardiac surgery at Cleveland Clinic, 125 with ischemic and 113 with nonischemic cardiomyopathy. Preoperative ejection fraction was 25 ± 4.5%. The primary outcome was postcardiotomy cardiogenic shock, defined as need for microaxial temporary left ventricular assist device, extracorporeal membrane oxygenation, or vasoactive-inotropic score >25. RandomForestSRC was used to identify its predictors.

RESULTS

Postcardiotomy cardiogenic shock occurred in 27% (65/238). Pulmonary artery pulsatility index <3.5 and pulmonary capillary wedge pressure >19 mm Hg were the most important factors predictive of postcardiotomy cardiogenic shock in ischemic cardiomyopathy. Cardiac index <2.2 L·min-1 m-2 and pulmonary capillary wedge pressure >21 mm Hg were the most important predictive factors in nonischemic cardiomyopathy. Operative mortality was 1.7%. Ejection fraction at 12 months after surgery increased to 39% (confidence interval, 35-40%) in the ischemic group and 37% (confidence interval, 35-38%) in the nonischemic cardiomyopathy group.

CONCLUSIONS

Predictors of postcardiotomy cardiogenic shock were different in ischemic and nonischemic cardiomyopathy. Right heart dysfunction, indicated by low pulmonary artery pulsatility index, was the most important predictor in ischemic cardiomyopathy, whereas greater degree of cardiac decompensation was the most important in nonischemic cardiomyopathy. Therefore, preoperative right heart catheterization will help identify patients with low ejection fraction who are at greater risk of postcardiotomy cardiogenic shock.

Mid-Term Outcome after Extracorporeal Life Support in Postcardiotomy Cardiogenic Shock: Recovery and Quality of Life

Background: Extracorporeal life support (ECLS) therapy for refractory postcardiotomy cardiogenic shock (rPCS) is associated with high early mortality rates. This study aimed to identify negative predictors of mid-term survival and to assess health-related quality of life (HRQoL) and recovery of the survivors. Methods: Between 2017 and 2020, 142 consecutive patients received ECLS therapy following cardiac surgery. The median age was 66.0 [57.0-73.0] years, 67.6% were male and the median EuroSCORE II was 10.5% [4.2-21.3]. In 48 patients, HRQoL was examined using the 36-Item Short Form Survey (SF-36) and the modified Rankin-Scale (mRS) at a median follow-up time of 2.2 [1.9-3.2] years. Results: Estimated survival rates at 3, 12, 24 and 36 months were 47%, 46%, 43% and 43% (SE: 4%). Multivariable Cox Proportional Hazard regression analysis revealed preoperative EuroSCORE II (p = 0.013), impaired renal function (p = 0.010), cardiopulmonary bypass duration (p = 0.015) and pre-ECLS lactate levels (p = 0.004) as independent predictors of mid-term mortality. At the time of follow-up, 83.3% of the survivors were free of moderate to severe disability (mRS < 3). SF-36 analysis showed a physical component summary of 45.5 ± 10.2 and a mental component summary of 50.6 ± 12.5. Conclusions: Considering the disease to be treated, ECLS for rPCS is associated with acceptable mid-term survival, health-related quality of life and functional status. Preoperative EuroSCORE II, impaired renal function, cardiopulmonary bypass duration and lactate levels prior to ECLS implantation were identified as negative predictors and should be included in the decision-making process.

Impact of Impella Support on Clinical Outcomes in Patients with Postcardiotomy Cardiogenic Shock

PURPOSE

This study aimed to elucidate the strategy of an effective Impella support for better clinical outcomes in patients with a postcardiotomy cardiogenic shock (PCCS).

METHODS

This single-center retrospective observational study enrolled 31 patients with PCCS undergoing an elective open-heart surgery followed by Impella support between November 2018 and February 2022 for further analysis.

RESULTS

The preoperative Euroscore II and left ventricular (LV) ejection fraction were 9.1 ± 10.4 and 35.7% ± 12.6%, respectively. The in-hospital mortality rate was 51.6% (n = 16). In survivors (n = 15), the mean Impella support time was 6.9 ± 3.5 days. Patients were discharged on the postoperative day 24.9 ± 16.4. Regarding LV remodeling, LV end-diastolic diameter was significantly decreased after Impella support (59.2 ± 6.0 mm vs. 54.4 ± 4.7 mm, p = 0.01, preoperative vs. postoperative). In-hospital mortality rates were comparable with small (CP, n = 6) or large (5.0, n = 25) Impella systems (33.3% [n = 2] vs. 56.0% [n = 14], p = 0.39). However, a lower in-hospital mortality rate was observed in the group with early initiation (i.e., intraoperative) of Impella support (n = 14) than that with delayed Impella initiation (i.e., in the postoperative course) (n = 11) (28.6% [n = 4] vs. 90.9% [n = 10], p = 0.004).

CONCLUSIONS

Impella support contributes to LV remodeling in PCCS patients. In-hospital mortality was comparable in different Impella sizes and lower in early Impella initiation.

The importance of timing in postcardiotomy venoarterial extracorporeal membrane oxygenation: A descriptive multicenter observational study

OBJECTIVES

Postcardiotomy extracorporeal membrane oxygenation (ECMO) can be initiated intraoperatively or postoperatively based on indications, settings, patient profile, and conditions. The topic of implantation timing only recently gained attention from the clinical community. We compare patient characteristics as well as in-hospital and long-term survival between intraoperative and postoperative ECMO.

METHODS

The retrospective, multicenter, observational Postcardiotomy Extracorporeal Life Support (PELS-1) study includes adults who required ECMO due to postcardiotomy shock between 2000 and 2020. We compared patients who received ECMO in the operating theater (intraoperative) with those in the intensive care unit (postoperative) on in-hospital and postdischarge outcomes.

RESULTS

We studied 2003 patients (women: 41.1%; median age: 65 years; interquartile range [IQR], 55.0-72.0). Intraoperative ECMO patients (n = 1287) compared with postoperative ECMO patients (n = 716) had worse preoperative risk profiles. Cardiogenic shock (45.3%), right ventricular failure (15.9%), and cardiac arrest (14.3%) were the main indications for postoperative ECMO initiation, with cannulation occurring after (median) 1 day (IQR, 1-3 days). Compared with intraoperative application, patients who received postoperative ECMO showed more complications, cardiac reoperations (intraoperative: 19.7%; postoperative: 24.8%, P = .011), percutaneous coronary interventions (intraoperative: 1.8%; postoperative: 3.6%, P = .026), and had greater in-hospital mortality (intraoperative: 57.5%; postoperative: 64.5%, P = .002). Among hospital survivors, ECMO duration was shorter after intraoperative ECMO (median, 104; IQR, 67.8-164.2 hours) compared with postoperative ECMO (median, 139.7; IQR, 95.8-192 hours, P < .001), whereas postdischarge long-term survival was similar between the 2 groups (P = .86).

CONCLUSIONS

Intraoperative and postoperative ECMO implantations are associated with different patient characteristics and outcomes, with greater complications and in-hospital mortality after postoperative ECMO. Strategies to identify the optimal location and timing of postcardiotomy ECMO in relation to specific patient characteristics are warranted to optimize in-hospital outcomes.

Extracorporeal Membrane Oxygenation in Postcardiotomy Cardiogenic Shock

Postcardiotomy extracorporeal membrane oxygenation (PC-ECMO), the most frequent indication for ECMO in the United States, is increasingly used as the first-line mechanical circulatory support in patients who are refractory to conventional treatment. Despite increasing use of PC-ECMO, limited evidence is available regarding its safety, efficacy, and optimal timing for initiation and weaning. The decision to use PC-ECMO often is made in the absence of robust clinical data, leading to variability in patient selection, management, and outcomes across different institutions. This article summarizes current evidence on ECMO use in postcardiotomy cardiogenic shock and discusses its potential benefits, management, complications, and outcomes.

A new machine learning algorithm to predict veno-arterial ECMO implantation after post-cardiotomy low cardiac output syndrome

BACKGROUND

Post-cardiotomy low cardiac output syndrome (PC-LCOS) is a life-threatening complication after cardiac surgery involving a cardiopulmonary bypass (CPB). Mechanical circulatory support with veno-arterial membrane oxygenation (VA-ECMO) may be necessary in the case of refractory shock. The objective of the study was to develop a machine-learning algorithm to predict the need for VA-ECMO implantation in patients with PC-LCOS.

PATIENTS AND METHODS

Patients were included in the study with moderate to severe PC-LCOS (defined by a vasoactive inotropic score (VIS) > 10 with clinical or biological markers of impaired organ perfusion or need for mechanical circulatory support after cardiac surgery) from two university hospitals in Paris, France. The Deep Super Learner, an ensemble machine learning algorithm, was trained to predict VA-ECMO implantation using features readily available at the end of a CPB. Feature importance was estimated using Shapley values.

RESULTS

Between January 2016 and December 2019, 285 patients were included in the development dataset and 190 patients in the external validation dataset. The primary outcome, the need for VA-ECMO implantation, occurred respectively, in 16% (n = 46) and 10% (n = 19) in the development and the external validation datasets. The Deep Super Learner algorithm achieved a 0.863 (0.793-0.928) ROC AUC to predict the primary outcome in the external validation dataset. The most important features were the first postoperative arterial lactate value, intraoperative VIS, the absence of angiotensin-converting enzyme treatment, body mass index, and EuroSCORE II.

CONCLUSIONS

We developed an explainable ensemble machine learning algorithm that could help clinicians predict the risk of deterioration and the need for VA-ECMO implantation in moderate to severe PC-LCOS patients.

Prophylactic LVAD for high-risk patients undergoing cardiac surgery

BACKGROUND

Postcardiotomy cardiogenic shock (PCS) is associated with poor prognosis. Medical therapy with afterload reduction, contractility optimization and systemic vasopressors often fails, and mechanical support is required. The aim of this study was to propose a strategy of prophylactic left ventricular assist device (LVAD) for high-risk patients undergoing cardiac surgery.

METHODS

Between 2013 and 2019, 12 consecutive patients at high risk for PCS underwent cardiac surgery (valve surgery and/or coronary artery bypass grafting) with preplanned, prophylactic implantation of LVAD (CentriMag or Rotaflow). We reviewed patient characteristics and outcomes.

RESULTS

Eight patients underwent a valve corrective surgery and seven patients underwent coronary artery bypass grafting. Eleven of 12 patients had successful LVAD insertion, support and wean, and survival to hospital discharge. Left ventricular function was stable perioperatively and improved at follow-up. Patients required low doses of inotropic support and no patients required extracorporeal membranous oxygenation. Major complications included, prolonged mechanical ventilation (n = 7), intra-aortic balloon pump (n = 1), temporary dialysis (n = 2), stroke (n = 1), bleeding requiring reoperation (n = 3), infection requiring mediastinal washout (n = 1). At a mean follow-up of, 660 ± 460.6 days all patients had either NYHA Class 1 (n = 6) or 2 (n = 4). There were two late mortalities (after 1 year).

CONCLUSIONS

Prophylactic LVAD is a viable technique in select cardiac surgery patients who are high-risk for postcardiotomy shock. Further prospective study is warranted.

Veno-arterial extracorporeal membrane oxygenation for drug intoxications: A single center, 14-year experience

BACKGROUND AND AIM OF THE STUDY

Acute cardiovascular failure remains a leading cause of death in severe poisonings. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used as a rescue therapeutic option for those cases refractory to optimal conventional treatment. We sought to evaluate the outcomes after VA-ECMO used for drug intoxications in a single-center experience.

METHODS

We performed an observational analysis of our prospective institutional database. The primary endpoint was survival to hospital discharge.

RESULTS

Between January 2007 and December 2020, 32 patients (mean age: 45.4 ± 15.8 years; 62.5% female) received VA-ECMO for drug intoxication-induced refractory cardiogenic shock (n = 25) or cardiac arrest (n = 7). Seven (21.8%) patients developed lower limb ischemia during VA-ECMO support. Twenty-six (81.2%) patients were successfully weaned after a mean VA-ECMO support of 2.9 ± 1.3 days. One (3.1%) patient died after VA-ECMO weaning for multiorgan failure and survival to hospital discharge was 78.1% (n = 25). In-hospital survivors were discharged from hospital with a good neurological status. Survival to hospital discharge was not statistically different according to sex (male = 75.0% vs. female = 80.0%; p = .535), type of intoxication (single drug = 81.8% vs. multiple drugs = 76.1%; p = .544) and location of VA-ECMO implantation (within our center = 75% vs. peripheral hospital using our Mobile Unit of Mechanical Circulatory Support = 100%; p = .352). Survival to hospital discharge was significantly lower in patients receiving VA-ECMO during on-going cardiopulmonary resuscitation (42.8% vs. 88.0%; p = .026).

CONCLUSIONS

VA-ECMO appears to be a feasible therapeutic option with a satisfactory survival rate and acceptable complications rate in poisonings complicated by refractory cardiogenic shock or cardiac arrest.

Veno-arterial extracorporeal membrane oxygenation for COVID-19-associated acute myocardial injury complicated by refractory cardiogenic shock

Cardiovascular system involvement and its negative prognostic impact have been increasingly identified in coronavirus disease 2019 (COVID‐19) patients. Optimal medical treatment allows for safe management of most of these cardiovascular presentations while COVID‐19‐associated refractory cardiogenic shock could be rescued by veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO). We present a case of acute myocardial injury related to COVID‐19 complicated by refractory cardiogenic shock and treated by VA‐ECMO implantation.

Weaning-Related Shock in Patients With ECMO: Incidence, Mortality, and Predisposing Factors

OBJECTIVE

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) commonly is used to manage refractory cardiogenic shock after cardiac surgery, with 31% to 76% of patients successfully weaned off their ECMO. However, it is associated with high mortality rates, and 20% to 65% of weaned patients do not survive to hospital discharge. This study aimed to assess the incidence of ECMO weaning-related shock, the risk factors, and prognosis in the intensive care unit (ICU).

DESIGN

Retrospective observational cohort study.

SETTING

Surgical ICU of Cardiology Institute of Pitié-Salpêtrière University Hospital (Paris-France).

PARTICIPANTS

Patients who were assisted with a peripheral VA-ECMO from January 2015 to December 2017 were included. Patients with venovenous, central, or right ECMO were excluded.

MEASUREMENTS

The authors collected data on patients' characteristics, during and after surgery. The indications for VA-ECMO implantation were ventricular dysfunction, primary graft dysfunction, and refractory cardiac arrest. Weaning-related shock was defined as the need to introduce or increase the dose of catecholamine at ECMO explantation or in the following week.

RESULTS

After weaning off VA-ECMO, 56 of 146 patients (38.4%) presented weaning-related shock: 55% were septic shocks, 12.5 % were caused by right ventricle failure, and 7.1% by hemorrhage. ICU mortality was 42% versus 8% in patients who did not present shock. Multivariate analysis showed that patients with pulmonary hypertension and those with norepinephrine before weaning were more likely to develop shock.

CONCLUSION

ECMO weaning-related shock is frequent in patients with refractory cardiogenic shock after cardiac surgery. This is most commonly caused by sepsis and causes higher mortality rates, calling for further evaluation.

Extubation and Noninvasive Ventilation of Patients Supported by Extracorporeal Life Support for Cardiogenic Shock: A Single-Center Retrospective Observational Cohort Study

Background:

Temporary extracorporeal life support (ECLS) by venoarterial extracorporeal membrane oxygenation is an emerging therapy for patients with severe, ongoing cardiogenic shock. After stabilization of the hemodynamic status and end-organ function, sedation weaning, extubation, and noninvasive ventilation (NIV) can be attempted. The goal of this study was to analyze the feasibility of extubation and NIV during versus after ECLS for cardiogenic shock.

Methods:

Single-center retrospective observational study of 132 patients undergoing ECLS due to severe cardiogenic shock between January 2015 and December 2016 at a tertiary care university hospital.

Results:

Patients received ECLS due to acute myocardial infarction (20.6%), ongoing cardiogenic shock (15.2%), postoperative low-cardiac-output syndrome (24.2%), and extracorporeal cardiopulmonary resuscitation (40.2%). Overall, intensive care unit survival was 44.7%. Sixty-nine (52.3%) patients could never be extubated. Forty-three (32.6%) were extubated while on ECLS support (group 1) and 20 (15.1%) were extubated after weaning from ECLS (group 2). Patients extubated during ECLS had a significantly shorter total time on ventilator (P = .003, mean difference: −284 hours [95% confidence limits: −83 to −484]) and more invasive ventilation free days (P = .0018; mean difference 8 days [95%CL: 2-14]). Mortality and NIV failure rates were similar between groups.

Conclusions:

Extubation and NIV are feasible in patients who stabilize during ECLS therapy. Further studies need to address whether extubation has the potential to improve patients outcome or if the feasibility to extubate is a surrogate for disease severeness.

Impact of age on outcomes of patients assisted by veno-arterial or veno-venous extra-corporeal membrane oxygenation: 403 patients between 2005 and 2015

INTRODUCTION

To assess the impact of age on early outcomes and mortality in veno-arterial extra-corporeal membrane oxygenation and veno-venous extra-corporeal membrane oxygenation recipients, and to investigate predictors of mortality.

METHODS

Single-center retrospective study on prospectively collected data including all patients treated by veno-venous extra-corporeal membrane oxygenation and veno-arterial extra-corporeal membrane oxygenation (January 2005-July 2015). Outcomes were compared among two subgroups: aged less than 65 years (Group 1) versus more than 65 years (Group 2) and by type of support (veno-arterial extra-corporeal membrane oxygenation or veno-venous extra-corporeal membrane oxygenation).

RESULTS

Among 403 patients, 20.3% were treated by veno-venous extra-corporeal membrane oxygenation and 79.7% by veno-arterial extra-corporeal membrane oxygenation. Veno-arterial extra-corporeal membrane oxygenation group: 76.6% were included in Group 1 and were more severe (pH 7.30 ± 0.19 vs. 7.35 ± 0.13 in Group 2, p = 0.003; lactates 7.5 ± 5.6 mmol/L vs. 5.8 ± 4.5 mmol/L in Group 2, p = 0.003). Weaning rate was higher in Group 1 (63.8% vs. 45.3%, p = 0.0043). The 30-day survival was higher in Group 1 (52.0% vs. 25.3%, p < 0.001). Univariate analysis identified higher Simplified Acute Physiology Score II (p = 0.02) and noradrenaline (p = 0.04) to be associated with mortality. Veno-venous extra-corporeal membrane oxygenation group: 80.5% were in Group 1. Mean PaO₂ was 73.5 ± 42.9 mm Hg versus 100.8 ± 80.3 mm Hg (p = 0.24); FiO₂ 90.1% ± 18% versus 89.4% ± 16.4% (p = 0.89); and 30-day survival 56.1% versus 25.0% (p = 0.048).

CONCLUSION

Patients older than 65 years have higher mortality after veno-arterial extra-corporeal membrane oxygenation or veno-venous extra-corporeal membrane oxygenation. This therapeutic strategy is feasible in the elderly, but comorbidities and clinical presentation have a major impact on prognosis and need to be seriously considered to avoid futile treatment.