Five-year survival after post-cardiotomy veno-arterial extracorporeal membrane oxygenation

Cardioprotection in cardiovascular surgery

Since the invention of cardiopulmonary bypass, cardioprotective strategies have been investigated to mitigate ischemic injury to the heart during aortic cross-clamping and reperfusion injury with cross-clamp release. With advances in cardiac surgical and percutaneous techniques and post-operative management strategies including mechanical circulatory support, cardiac surgeons are able to operate on more complex patients. Therefore, there is a growing need for improved cardioprotective strategies to optimize outcomes in these patients. This review provides an overview of the basic principles of cardioprotection in the setting of cardiac surgery, including mechanisms of cardiac injury in the context of cardiopulmonary bypass, followed by a discussion of the specific approaches to optimizing cardioprotection in cardiac surgery, including refinements in cardiopulmonary bypass and cardioplegia, ischemic conditioning, use of specific anesthetic and pharmaceutical agents, and novel mechanical circulatory support technologies. Finally, translational strategies that investigate cardioprotection in the setting of cardiac surgery will be reviewed, with a focus on promising research in the areas of cell-based and gene therapy. Advances in this area will help cardiologists and cardiac surgeons mitigate myocardial ischemic injury, improve functional post-operative recovery, and optimize clinical outcomes in patients undergoing cardiac surgery.

Scrutinizing the Role of Venoarterial Extracorporeal Membrane Oxygenation: Has Clinical Practice Outpaced the Evidence?

The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for temporary mechanical circulatory support in various clinical scenarios has been increasing consistently, despite the lack of sufficient evidence regarding its benefit and safety from adequately powered randomized controlled trials. Although the ARREST trial (Advanced Reperfusion Strategies for Patients with Out-of-Hospital Cardiac Arrest and Refractory Ventricular Fibrillation) and a secondary analysis of the PRAGUE OHCA trial (Prague Out-of-Hospital Cardiac Arrest) provided some evidence in favor of VA-ECMO in the setting of out-of-hospital cardiac arrest, the INCEPTION trial (Early Initiation of Extracorporeal Life Support in Refractory Out-of-Hospital Cardiac Arrest) has not found a relevant improvement of short-term mortality with extracorporeal cardiopulmonary resuscitation. In addition, the results of the recently published ECLS-SHOCK trial (Extracorporeal Life Support in Cardiogenic Shock) and ECMO-CS trial (Extracorporeal Membrane Oxygenation in the Therapy of Cardiogenic Shock) discourage the routine use of VA-ECMO in patients with infarct-related cardiogenic shock. Ongoing clinical trials (ANCHOR [Assessment of ECMO in Acute Myocardial Infarction Cardiogenic Shock, NCT04184635], REVERSE [Impella CP With VA ECMO for Cardiogenic Shock, NCT03431467], UNLOAD ECMO [Left Ventricular Unloading to Improve Outcome in Cardiogenic Shock Patients on VA-ECMO, NCT05577195], PIONEER [Hemodynamic Support With ECMO and IABP in Elective Complex High-risk PCI, NCT04045873]) may clarify the usefulness of VA-ECMO in specific patient subpopulations and the efficacy of combined mechanical circulatory support strategies. Pending further data to refine patient selection and management recommendations for VA-ECMO, it remains uncertain whether the present usage of this device improves outcomes.

Postcardiotomy Shock Syndrome: A Narrative Review of Perioperative Diagnosis and Management

Postcardiotomy shock (PCS) is generally described as the inability to separate from cardiopulmonary bypass due to ineffective cardiac output after cardiotomy, which is caused by a primary cardiac disorder, resulting in inadequate tissue perfusion. Postcardiotomy shock occurs in 0.5% to 1.5% of contemporary cardiac surgery cases, and is accompanied by an in-hospital mortality of approximately 67%. In the last 2 decades, the incidence of PCS has increased, likely due to the increased age and baseline morbidity of patients requiring cardiac surgery. In this narrative review, the authors discuss the epidemiology and pathophysiology of PCS, the rationale and evidence behind the initiation, continuation, escalation, and discontinuation of mechanical support devices in PCS, and the anesthetic implications.

On-Support and Postweaning Mortality in Postcardiotomy Extracorporeal Membrane Oxygenation

BACKGROUND

Postcardiotomy venoarterial extracorporeal membrane oxygenation (VA ECMO) is characterized by discrepancies between weaning and survival-to-discharge rates. This study analyzes the differences between postcardiotomy VA ECMO patients who survived, died on ECMO, or died after ECMO weaning. Causes of death and variables associated with mortality at different time points are investigated.

METHODS

The retrospective, multicenter, observational Postcardiotomy Extracorporeal Life Support Study (PELS) includes adults requiring postcardiotomy VA ECMO between 2000 and 2020. Variables associated with on-ECMO mortality and postweaning mortality were modeled using mixed Cox proportional hazards, including random effects for center and year.

RESULTS

In 2058 patients (men, 59%; median age, 65 years; interquartile range [IQR], 55-72 years), weaning rate was 62.7%, and survival to discharge was 39.6%. Patients who died (n = 1244) included 754 on-ECMO deaths (36.6%; median support time, 79 hours; IQR, 24-192 hours), and 476 postweaning deaths (23.1%; median support time, 146 hours; IQR, 96-235.5 hours). Multiorgan (n = 431 of 1158 [37.2%]) and persistent heart failure (n = 423 of 1158 [36.5%]) were the main causes of death, followed by bleeding (n = 56 of 754 [7.4%]) for on-ECMO mortality and sepsis (n = 61 of 401 [15.4%]) for postweaning mortality. On-ECMO death was associated with emergency surgery, preoperative cardiac arrest, cardiogenic shock, right ventricular failure, cardiopulmonary bypass time, and ECMO implantation timing. Diabetes, postoperative bleeding, cardiac arrest, bowel ischemia, acute kidney injury, and septic shock were associated with postweaning mortality.

CONCLUSIONS

A discrepancy exists between weaning and discharge rate in postcardiotomy ECMO. Deaths occurred during ECMO support in 36.6% of patients, mostly associated with unstable preoperative hemodynamics. Another 23.1% of patients died after weaning in association with severe complications. This underscores the importance of postweaning care for postcardiotomy VA ECMO patients.

Patient and Management Variables Associated With Survival After Postcardiotomy Extracorporeal Membrane Oxygenation in Adults: The PELS-1 Multicenter Cohort Study

Background Extracorporeal membrane oxygenation (ECMO) has been increasingly used for postcardiotomy cardiogenic shock, but without a concomitant reduction in observed in-hospital mortality. Long-term outcomes are unknown. This study describes patients' characteristics, in-hospital outcome, and 10-year survival after postcardiotomy ECMO. Variables associated with in-hospital and postdischarge mortality are investigated and reported. Methods and Results The retrospective international multicenter observational PELS-1 (Postcardiotomy Extracorporeal Life Support) study includes data on adults requiring ECMO for postcardiotomy cardiogenic shock between 2000 and 2020 from 34 centers. Variables associated with mortality were estimated preoperatively, intraoperatively, during ECMO, and after the occurrence of any complications, and then analyzed at different time points during a patient's clinical course, through mixed Cox proportional hazards models containing fixed and random effects. Follow-up was established by institutional chart review or contacting patients. This analysis included 2058 patients (59% were men; median [interquartile range] age, 65.0 [55.0-72.0] years). In-hospital mortality was 60.5%. Independent variables associated with in-hospital mortality were age (hazard ratio [HR], 1.02 [95% CI, 1.01-1.02]) and preoperative cardiac arrest (HR, 1.41 [95% CI, 1.15-1.73]). In the subgroup of hospital survivors, the overall 1-, 2-, 5-, and 10-year survival rates were 89.5% (95% CI, 87.0%-92.0%), 85.4% (95% CI, 82.5%-88.3%), 76.4% (95% CI, 72.5%-80.5%), and 65.9% (95% CI, 60.3%-72.0%), respectively. Variables associated with postdischarge mortality included older age, atrial fibrillation, emergency surgery, type of surgery, postoperative acute kidney injury, and postoperative septic shock. Conclusions In adults, in-hospital mortality after postcardiotomy ECMO remains high; however, two-thirds of those who are discharged from hospital survive up to 10 years. Patient selection, intraoperative decisions, and ECMO management remain key variables associated with survival in this cohort. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03857217.

Variables associated with in-hospital and postdischarge outcomes after postcardiotomy extracorporeal membrane oxygenation: Netherlands Heart Registration Cohort

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) for postcardiotomy cardiogenic shock has been increasingly used without concomitant mortality reduction. This study aims to investigate determinants of in-hospital and postdischarge mortality in patients requiring postcardiotomy ECMO in the Netherlands.

METHODS

The Netherlands Heart Registration collects nationwide prospective data from cardiac surgery units. Adults receiving intraoperative or postoperative ECMO included in the register from January 2013 to December 2019 were studied. Survival status was established through the national Personal Records Database. Multivariable logistic regression analyses were used to investigate determinants of in-hospital (3 models) and 12-month postdischarge mortality (4 models). Each model was developed to target specific time points during a patient's clinical course.

RESULTS

Overall, 406 patients (67.2% men, median age, 66.0 years [interquartile range, 55.0-72.0 years]) were included. In-hospital mortality was 51.7%, with death occurring in a median of 5 days (interquartile range, 2-14 days) after surgery. Hospital survivors (n = 196) experienced considerable rates of pulmonary infections, respiratory failure, arrhythmias, and deep sternal wound infections during a hospitalization of median 29 days (interquartile range, 17-51 days). Older age (odds ratio [OR], 1.02; 95% CI, 1.0-1.04) and preoperative higher body mass index (OR, 1.08; 95% CI, 1.02-1.14) were associated with in-hospital death. Within 12 months after discharge, 35.1% of hospital survivors (n = 63) died. Postoperative renal failure (OR, 2.3; 95% CI, 1.6-4.9), respiratory failure (OR, 3.6; 95% CI, 1.3-9.9), and re-thoracotomy (OR, 2.9; 95% CI, 1.3-6.5) were associated with 12-month postdischarge mortality.

CONCLUSIONS

In-hospital and postdischarge mortality after postcardiotomy ECMO in adults remains high in the Netherlands. ECMO support in patients with higher age and body mass index, which drive associations with higher in-hospital mortality, should be carefully considered. Further observations suggest that prevention of re-thoracotomies, renal failure, and respiratory failure are targets that may improve postdischarge outcomes.

Postcardiotomy Venoarterial Extracorporeal Membrane Oxygenation With and Without Intra-Aortic Balloon Pump

OBJECTIVES

To compare the outcomes of patients with postcardiotomy shock treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO) only compared with VA-ECMO and intra-aortic balloon pump (IABP).

DESIGN

A retrospective multicenter registry study.

SETTING

At 19 cardiac surgery units.

PARTICIPANTS

A total of 615 adult patients who required VA-ECMO from 2010 to 2018. The patients were divided into 2 groups depending on whether they received VA-ECMO only (ECMO only group) or VA-ECMO plus IABP (ECMO-IABP group).

MEASUREMENTS AND MAIN RESULTS

The overall series mean age was 63 ± 13 years, and 33% were female. The ECMO-only group included 499 patients, and 116 patients were in the ECMO-IABP group. Urgent and/or emergent procedures were more common in the ECMO-only group. Central cannulation was performed in 47% (n = 54) in the ECMO-IABP group compared to 27% (n = 132) in the ECMO-only group. In the ECMO-IABP group, 58% (n = 67) were successfully weaned from ECMO, compared to 46% (n = 231) in the ECMO-only group (p = 0.026). However, in-hospital mortality was 63% in the ECMO-IABP group compared to 65% in the ECMO-only group (p = 0.66). Among 114 propensity score-matched pairs, ECMO-IABP group had comparable weaning rates (57% v 53%, p = 0.51) and in-hospital mortality (64% v 58%, p = 0.78).

CONCLUSIONS

This multicenter study showed that adjunctive IABP did not translate into better outcomes in patients treated with VA-ECMO for postcardiotomy shock.

Access site complications of postcardiotomy extracorporeal life support

OBJECTIVE

To assess the influence of primary arterial access in patients receiving peripheral postcardiotomy extracorporeal life support on associated complications and outcome.

METHODS

Of 573 consecutive patients requiring PC-ECLS between 2000 and 2019 at a single center, 436 were included in a retrospective analysis and grouped according to primary arterial extracorporeal life support access site. Survival and rate of access-site-related complications with special emphasis on fatal/disabling stroke were compared.

RESULTS

The axillary artery was cannulated in 250 patients (57.3%), whereas the femoral artery was used as primary arterial access in 186 patients (42.6%). There was no significant difference in 30-day (axillary: 62%; femoral: 64.7%; P = .561) and 1-year survival (axillary: 42.5%; femoral: 44.8%; P = .657). Cerebral computed tomography-confirmed stroke with a modified ranking scale ≥4 was significantly more frequent in the axillary group (axillary: n = 28, 11.2%; femoral: n = 4, 2.2%; P = .0003). Stroke localization was right hemispheric (n = 20; 62.5%); left hemispheric (n = 5; 15.6%), bilateral (n = 5; 15.6%), or infratentorial (n = 2; 6.25%). Although no difference in major cannulation site bleeding was observed, cannulation site change for bleeding was more frequent in the axillary group (axillary: n = 13; 5.2%; femoral: n = 2; 1.1%; P = .03). Clinically apparent limb ischemia was significantly more frequent in the femoral group (axillary: n = 12, 4.8%; femoral: n = 31, 16.7%; P < .0001).

CONCLUSIONS

Although survival did not differ, surgeons should be aware of access-site-specific complications when choosing peripheral PC-ECLS access. Although lower rates of limb ischemia and the advantage of antegrade flow seem beneficial for axillary cannulation, the high incidence of right hemispheric strokes in axillary artery cannulation should be considered.

Utilization and outcomes of postcardiotomy mechanical circulatory support

BACKGROUND

This study evaluated the utilization and outcomes of postcardiotomy mechanical circulatory support (MCS).

METHODS

This was a retrospective, single institution analysis of adult cardiac surgery cases that required de novo MCS following surgery from 2011 to 2018. Patients that were bridged with MCS to surgery were excluded. The primary outcomes were early operative mortality and longitudinal survival. Secondary outcomes included postoperative complications, and 5-year all-cause readmission.

RESULTS

Five hundred and thirty-three patients required de novo postcardiotomy MCS, with the most commonly performed procedure being isolated coronary artery bypass grafting (29.8%). Median cardiopulmonary bypass and cross-clamp times were 185 (IQR 123-260) min and 122 (IQR 81-179) min, respectively. A total of 442 (82.9%) of patients were supported with intra-aortic balloon pump counterpulsation, 23 (4.3%) with an Impella device, and 115 (21.6%) with extracorporeal membrane oxygenation. Three (0.6%) patients had an unplanned ventricular assist device placed. Operative mortality was 29.8%. Longitudinal survival was 56.1% and 43.0% at 1 and 5 years, respectively. Survival was lowest in those supported with ECMO and highest with those supported with an Impella (p < 0.001). Freedom from readmission was 61.4% at 5 years. Postoperative ECMO was an independent predictor of mortality (HR 5.1, 95% CI 2.0-12.9, p < 0.001), but none of the MCS types predicted long-term hospital readmission after risk adjustment.

CONCLUSIONS

Postcardiotomy MCS is associated with high operative mortality. Even patients that survive to discharge have compromised longitudinal survival, with nearly only half surviving to 1 year. Close follow-up and early referral to advanced heart failure specialists may be prudent in improving these outcomes.