Predictors of in-hospital mortality and midterm outcomes of patients successfully weaned from venoarterial extracorporeal membrane oxygenation

Extracorporal Membrane Oxygenation in Massive Pulmonary Embolism

BACKGROUND

Massive pulmonary embolism (MPE) carries significant 30-day mortality risk, and a change in societal guidelines has promoted the increasing use of extracorporeal membrane oxygenation (ECMO) in the immediate management of MPE-associated cardiovascular shock. This narrative review examines the current status of ECMO in MPE.

METHODS

A literature review was performed from 1982 to 2022 searching for the terms "Pulmonary embolism" and "ECMO," and the search was refined by examining those publications that covered MPE.

RESULTS

In the patient with MPE, veno-arterial ECMO is now recommended as a bridge to interventional therapy. It can reliably decrease right ventricular overload, improve RV function, and allow hemodynamic stability and restoration of tissue oxygenation. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Applying ECMO is also associated with substantial multisystem morbidity due to systemic inflammatory response, bleeding with coagulopathy, hemorrhagic stroke, renal dysfunction, and acute limb ischemia, which must be factored into the outcomes.

CONCLUSIONS

The application of ECMO in MPE should be combined with an aggressive interventional pulmonary interventional program and should strictly adhere to the current selection criteria.

Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock

OBJECTIVE

Although extracorporeal life support (ECLS) has increasingly been used for the treatment of patients with cardiogenic shock (CS), the outcomes of those successfully weaned from support remain poorly defined.

METHODS

Of 510 venoarterial ECLS CS patients at our institution between January 2015 and December 2020, 249 were decannulated and survived for 30 days or until discharge (ie, successfully weaned). Factors associated with survival to discharge were assessed and 1-year survival was described.

RESULTS

Of 510 eligible CS ECLS patients, 249 (48.8%) were successfully decannulated, 227 (44.5%) died during/following ECLS, and 34 (6.7%) were bridged to heart transplantation or a ventricular assist device. Patients with a primary graft dysfunction etiology of CS had a greater chance of successful decannulation (odds ratio [OR], 3.088; 95% CI, 1.1-8.671; P = .0323), whereas patients with ECLS during cardiopulmonary resuscitation had a reduced chance of successful decannulation (OR, 0.354; 95% CI, 0.17-0.735; P = .0054). Of successfully decannulated patients, 218 (87.6%) survived to hospital discharge and 31 (12.4%) died in the hospital. Acute myocardial infarction etiology (OR, 4.751; 95% CI, 1.623-13.902; P = .0044), preexisting chronic kidney disease (OR, 3.422; 95% CI, 1.374-8.52; P = .0082), and initiation of continuous renal replacement therapies (OR, 3.188; 95% CI, 1.291-7.871; P = .012) were significantly associated with in-hospital mortality despite successful decannulation. One-year survival in successfully decannulated patients surviving to hospital discharge was 95.0% and comparable to 1-year survival in patients who received a heart transplant or ventricular assist device.

CONCLUSIONS

Successful decannulation can be achieved in a significant proportion of patients treated with ECLS for CS but does not guarantee survival to hospital discharge. However, 1-year survival of hospital survivors remains high and is comparable to patients bridged to transplant or a ventricular assist device.

Long-term outcomes of patients bridged to recovery with venoarterial extracorporeal life support

OBJECTIVE

Our study examines the long-term outcomes of patients discharged from the hospital without heart replacement therapy (HRT) after recovery from cardiogenic shock using venoarterial extracorporeal life support (VA-ECLS).

METHODS

We retrospectively reviewed 615 cardiogenic shock patients who recovered from VA-ECLS at our institution between January 2015 and July 2021. Of those, 166 patients (27.0%) who recovered from VA-ECLS without HRT were included in this study. Baseline characteristics, discharge labs, vitals, electrocardiograms and echocardiograms were assessed. Patients were contacted to determine vital status. The primary outcome was post-discharge mortality.

RESULTS

Of 166 patients, 158 patients (95.2%) had post-discharge follow-up, with a median time of follow-up of 2 years (IQR: [1 year, 4 years]). At discharge, the median ejection fraction (EF) was 52.5% (IQR: [32.5, 57.5]). At discharge, 92 patients (56%) were prescribed β-blockers, 28 (17%) were prescribed an ACE inhibitor, ARB or ARNI, and 50 (30%) were prescribed loop diuretics. Kaplan-Meier analysis showed a 1-year survival rate of 85.6% (95% CI: [80.1%, 91.2%]) and a 5-year survival rate of 60.6% (95% CI: [49.9%, 71.3%]). A Cox regression model demonstrated that a history of congestive heart failure (CHF) was strongly predictive of increased mortality hazard (HR = 1.929; p = 0.036), while neither discharge EF nor etiology of VA-ECLS were associated with increased post-discharge mortality.

CONCLUSIONS

Patients discharged from the hospital after full myocardial recovery from VA-ECLS support without HRT should have close outpatient follow-up due to the risk of recurrent heart failure and increased mortality in these patients.

Sounding the Alarm: What Clinicians Need to Know about Physical, Emotional, and Cognitive Recovery After Venoarterial Extracorporeal Membrane Oxygenation

OBJECTIVE

We summarize the existing data on the occurrence of physical, emotional, and cognitive dysfunction associated with postintensive care syndrome (PICS) in adult survivors of venoarterial extracorporeal membrane oxygenation (VA-ECMO).

DATA SOURCES

MEDLINE, Cochrane Library, EMBASE, Web of Science, and CINAHL databases were searched.

STUDY SELECTION

Peer-reviewed studies of adults receiving VA-ECMO for any reason with at least one measure of health-related quality of life outcomes or PICS at long-term follow-up of at least 6 months were included.

DATA EXTRACTION

The participant demographics and baseline characteristics, in-hospital outcomes, long-term health outcomes, quality of life outcome measures, and prevalence of PICS were extracted.

DATA SYNTHESIS

Twenty-seven studies met inclusion criteria encompassing 3,271 patients who were treated with VA-ECMO. The studies were limited to single- or two-center studies. Outcomes variables and follow-up time points evaluated were widely heterogeneous which limits comprehensive analysis of PICS after VA-ECMO. In general, the longer-term PICS-related outcomes of survivors of VA-ECMO were worse than the general population, and approaching that of patients with chronic disease. Available studies identified high rates of abnormal 6-minute walk distance, depression, anxiety, and posttraumatic stress disorder that persisted for years. Half or fewer survivors return to work years after discharge. Only 2 of 27 studies examined cognitive outcomes and no studies evaluated cognitive dysfunction within the first year of recovery. No studies evaluated the impact of targeted interventions on these outcomes.

CONCLUSIONS

Survivors of VA-ECMO represent a population of critically ill patients at high risk for deficits in physical, emotional, and cognitive function related to PICS. This systematic review highlights the alarming reality that PICS and in particular, neurocognitive outcomes, in survivors of VA-ECMO are understudied, underrecognized, and thus likely undertreated. These results underscore the imperative that we look beyond survival to focus on understanding the burden of survivorship with the goal of optimizing recovery and outcomes after these life-saving interventions. Future prospective, multicenter, longitudinal studies in recovery after VA-ECMO are justified.

Risk factors for cannula-associated arterial thrombosis following extracorporeal membrane oxygenation support: a retrospective study

BACKGROUND

Hemostatic dysfunction during extracorporeal membrane oxygenation (ECMO) due to blood-circuit interaction and the consequences of shear stress imposed by flow rates lead to rapid coagulation cascade and thrombus formation in the ECMO system and blood vessels. We aimed to identify the incidence and risk factors for cannula-associated arterial thrombosis (CaAT) post-decannulation.

METHODS

A retrospective study of patients undergoing arterial cannula removal following ECMO was performed. We evaluated the incidence of CaAT and compared the characteristics, ECMO machine parameters, cannula sizes, number of blood products transfused during ECMO, and daily hemostasis parameters in patients with and without CaAT. Multivariate analysis identified the risk factors for CaAT.

RESULTS

Forty-seven patients requiring venoarterial ECMO (VA-ECMO) or hybrid methods were recruited for thrombosis screening. The median Sequential Organ Failure Assessment score was 11 (interquartile range, 8-13). CaAT occurred in 29 patients (61.7%), with thrombosis in the superficial femoral artery accounting for 51.7% of cases. The rate of limb ischemia complications in the CaAT group was 17.2%. Multivariate analysis determined that the ECMO flow rate-body surface area (BSA) ratio (100 ml/min/m2) was an independent factor for CaAT, with an odds ratio of 0.79 (95% confidence interval, 0.66-0.95; P=0.014).

CONCLUSIONS

We found that the incidence of CaAT was 61.7% following successful decannulation from VA-ECMO or hybrid modes, and the ECMO flow rate-BSA ratio was an independent risk factor for CaAT. We suggest screening for arterial thrombosis following VA-ECMO, and further research is needed to determine the risks and benefits of such screening.

Feasibility of pump-controlled retrograde trial off in weaning from veno-arterial ECMO in adults-A single-center case series

BACKGROUND

Various strategies of weaning V-A ECMO have been described. PCRTO is a weaning technique which involves serial decremental pump revolutions until a retrograde flow from the arterial to venous ECMO cannula is achieved. It has been reported as a feasible weaning strategy in the pediatric population, but its application in adults has not been widely reported.

METHODS

This was a case series including all adult patients who underwent PCRTO during weaning from V-A ECMO at a tertiary ECMO center between January 2019 and July 2021. The primary end point was the successful weaning from V-A ECMO support.

RESULTS

A total of 57 runs of PCRTO in 36 patients were analyzed-45 (78.9%) of the trials were concluded successfully. The median retrograde blood flow rate during PCRTO was 0.6 ± 0.2 L/min, and the median duration of each PCRTO was 180 (120-240) min. Of the 35 patients who had at least one session of successful PCRTO, 31 (88.6%) were ultimately weaned from ECMO. There were no major complications from PCRTO including systemic or circuit thrombosis.

CONCLUSIONS

PCRTO is a feasible strategy for assessing readiness for weaning from V-A ECMO with a low risk of adverse events and high rate of predicting eventual successful ECMO decannulation. Further investigation including comparison with alternative weaning strategies in prospective studies is required to confirm the approach.

The role of temporary mechanical circulatory support as a bridge to advanced heart failure therapies or recovery

PURPOSE OF REVIEW

Temporary mechanical circulatory support (tMCS) has become central in the treatment of refractory cardiogenic shock and can be used to bridge patients to durable MCS, heart transplant or recovery. This review will discuss contemporary data regarding bridging strategies utilizing tMCS.

RECENT FINDINGS

There has been significant growth in tMCS use recently, driven by increased familiarity with tMCS devices, and increased experience with both implantation and management. Identifying goals of therapy at the time of therapy initiation can facilitate better outcomes. The three primary goals are bridge to recovery, bridge to heart transplantation or bridge to durable left ventricular assist device. Bridging to recovery requires adequate treatment of underlying conditions and optimization of haemodynamics. Bridging to heart transplantation has become more frequent following changes to the heart allocation policy. Despite early concerns, patients bridge with tMCS, including ventricular-arterial extracorporeal membrane oxygenation, do not appear to have worse posttransplant outcomes. When bridging to durable mechanical circulatory support, tMCS can be used to enhance end-organ dysfunction and improve perioperative outcomes. In situations in which none of these goals are attainable, palliative care plays a critical role to identify patient wishes and assist with withdrawal of care when necessary.

SUMMARY

The use of tMCS, as a bridge to recovery or heart replacement therapy in patients with refractory cardiogenic shock has grown significantly over the past decade. Multiple device choices are available and must be chosen appropriately to address the specific situation and the goals of therapy.

Mid-term outcomes with the use of extracorporeal membrane oxygenation for cardiopulmonary failure secondary to massive pulmonary embolism

OBJECTIVES

There has been increasing interest in using extracorporeal membrane oxygenation (ECMO) to rescue patients with pulmonary embolism (PE) in the advanced stages of respiratory or haemodynamic decompensation. We examined mid-term outcomes and risk factors for in-hospital mortality.

METHODS

We conducted a retrospective study of 36 patients who required ECMO placement (32 veno-arterial ECMO, 4 veno-venous) following acute PE. Survival curves were estimated using the Kaplan-Meier method. Risk factors for in-hospital mortality were assessed by logistic regression analysis. Functional status and quality of life were assessed by phone questionnaire.

RESULTS

Overall survival to hospital discharge was 44.4% (16/36). Two-year survival conditional to discharge was 94% (15/16). Two-year survival after veno-arterial ECMO was 39% (13/32). In patients supported with veno-venous ECMO, survival to discharge was 50%, and both patients were alive at follow-up. In univariable analysis, a history of recent surgery (P = 0.064), low left ventricular ejection fraction (P = 0.029), right ventricular dysfunction ≥ moderate at weaning (P = 0.083), on-going cardiopulmonary resuscitation at ECMO placement (P = 0.053) and elevated lactate at weaning (P = 0.002) were risk factors for in-hospital mortality. In multivariable analysis, recent surgery (P = 0.018) and low left ventricular ejection fraction at weaning (P = 0.013) were independent factors associated with in-hospital mortality. At a median follow-up of 23 months, 10 patients responded to our phone survey; all had acceptable functional status and quality of life.

CONCLUSIONS

Massive acute PE requiring ECMO support is associated with high early mortality, but patients surviving to hospital discharge have excellent mid-term outcomes with acceptable functional status and quality of life. ECMO can provide a stable platform to administer other intervention with the potential to improve outcomes. Risk factors for in-hospital mortality after PE and veno-arterial ECMO support were identified.

Risk factors for complete recovery of adults after weaning from veno-venous extracorporeal membrane oxygenation for severe acute respiratory failure: an analysis from adult patients in the Extracorporeal Life Support Organization registry

BACKGROUND

As extracorporeal membrane oxygenation (ECMO) has been widely used, the patient quality of life following ECMO termination has become an important issue as same as the patient's survival. To date, the factors affecting complete recovery of adult survivors from ECMO have not been investigated.

METHODS

Data from adult patients in the Extracorporeal Life Support Organization registry who received veno-venous ECMO between 2012 and 2017 were analyzed. Multivariate logistic regression analyses were conducted.

RESULTS

In total, 6536 patients with 242,183 days of veno-venous ECMO were reviewed. The overall survival to discharge rate after weaning from ECMO was 89.7% (n = 5861), and 10.3% (n = 675) of the patients died during hospitalization. The discharge location varied as follows: 33.7% (n = 1976) returned home, 23.4% (n = 1369) were transferred to a referral hospital, 41.8% (n = 2447) required hospital services, and 0.6% (n = 36) were discharged to other places. The patients were divided into two groups according to the discharge location: a complete recovery group (n = 1976) and a partial recovery group (n = 3885). In the multivariate analyses, age (≥ 65 years) (odds ratio (OR) 0.72, 95% confidence interval (CI) 0.59-0.87, p = 0.001), cardiac arrest before ECMO (OR 0.76, 95% CI 0.60-0.96, p = 0.021), vasopressor use (OR 0.73, 95% CI 0.64-0.83, p < 0.001), renal replacement therapy (OR 0.40, 95% CI 0.28-0.57, p < 0.001), ECMO-related complications (OR 0.76, 95% CI 0.67-0.85, p < 0.001), and long-term ECMO support (≥ 2 weeks) (OR 0.42, 95% CI 0.37-0.48, p < 0.001) were significantly associated with complete recovery.

CONCLUSION

Complete recovery after veno-venous ECMO support is associated with the patient's baseline condition, ECMO duration, and ECMO-related complications. Respiratory ECMO should aim to increase both the survival and the quality of life after weaning from ECMO.

Update on Weaning from Veno-Arterial Extracorporeal Membrane Oxygenation

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides temporary cardiac and respiratory support and has emerged as an established salvage intervention for patients with hemodynamic compromise or shock. It is thereby used as a bridge to recovery, bridge to permanent ventricular assist devices, bridge to transplantation, or bridge to decision. However, weaning from VA-ECMO differs between centers, and information about standardized weaning protocols are rare. Given the high mortality of patients undergoing VA-ECMO treatment, it is all the more important to answer the many questions still remaining unresolved in this field Standardized algorithms are recommended to optimize the weaning process and determine whether the VA-ECMO can be safely removed. Successful weaning as a multifactorial process requires sufficient recovery of myocardial and end-organ function. The patient should be considered hemodynamically stable, although left ventricular function often remains impaired during and after weaning. Echocardiographic and invasive hemodynamic monitoring seem to be indispensable when evaluating biventricular recovery and in determining whether the VA-ECMO can be weaned successfully or not, whereas cardiac biomarkers may not be useful in stratifying those who will recover. This review summarizes the strategies of weaning of VA-ECMO and discusses predictors of successful and poor weaning outcome.