The impact of Centre's heart transplant status and volume on in-hospital outcomes following extracorporeal membrane oxygenation for refractory post-cardiotomy cardiogenic shock: a meta-analysis

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.

Quality improvement strategies in pediatric ECMO

Pediatric extracorporeal membrane oxygenation is an increasingly utilized, life-saving technology with high mortality and morbidity. A complex technology employed urgently or emergently for some of the sickest children in the hospital by a large multidisciplinary team, ECMO is an ideal area for using quality improvement strategies to reduce the variability in care and improve patient outcomes. We review critical concepts from quality improvement and apply them to patient selection and management, staffing, credentialing and continuing education, and the variability of management among providers and institutions.

Impella Versus VA-ECMO for Patients with Cardiogenic Shock: Comprehensive Systematic Literature Review and Meta-Analyses

Impella and VA-ECMO are two possible therapeutic courses for the treatment of patients with cardiogenic shock (CS). The study aims to perform a systematic literature review and meta-analyses of a comprehensive set of clinical and socio-economic outcomes observed when using Impella or VA-ECMO with patients under CS. A systematic literature review was performed in Medline, and Web of Science databases on 21 February 2022. Nonoverlapping studies with adult patients supported for CS with Impella or VA-ECMO were searched. Study designs including RCTs, observational studies, and economic evaluations were considered. Data on patient characteristics, type of support, and outcomes were extracted. Additionally, meta-analyses were performed on the most relevant and recurring outcomes, and results shown using forest plots. A total of 102 studies were included, 57% on Impella, 43% on VA-ECMO. The most common outcomes investigated were mortality/survival, duration of support, and bleeding. Ischemic stroke was lower in patients treated with Impella compared to the VA-ECMO population, with statistically significant difference. Socio-economic outcomes including quality of life or resource use were not reported in any study. The study highlighted areas where further data collection is needed to clarify the value of complex, new technologies in the treatment of CS that will enable comparative assessments focusing both on the health impact on patient outcomes and on the financial burden for government budgets. Future studies need to fill the gap to comply with recent regulatory updates at the European and national levels.

Similarities in extracorporeal membrane oxygenation management across intensive care unit types in the United States: An analysis of the Extracorporeal Life Support Organization Registry

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) use in the United States occurs often in cardiothoracic ICUs (CTICU). It is unknown how it varies across ICU types.

METHODS

We identified 10,893 ECMO runs from the Extracorporeal Life Support Organization (ELSO) Registry across 2018 and 2019. Primary outcome was ECMO case volume by ICU type (CTICU vs. non-CTICU). Adjusting for pre-ECMO characteristics and case mix, secondary outcomes were on-ECMO physiologic variables by ICU location stratified by support type.

RESULTS

CTICU ECMO occurred in 65.1% and 55.1% (2018 and 2019) of total runs. A minority of total runs related to cardiac surgery procedures (CTICU: 21.7% [2018], 18% [2019]; non-CTICU: 11.2% [2018], 13% [2019]). After multivariate adjustment, non-CTICU ECMO for cardiac support associated with lower 4- and 24-hour circuit flow (3.9 liters per minute [LPM] vs. 4.1 LPM, p<0.0001; 4.1 LPM vs. 4.3 LPM, p<0.0001); for respiratory support, lower on-ECMO mean fraction of inspired oxygen ([F_i O₂ ], 67% versus 69%, p=0.02) and lower respiratory rate (14 versus 15, p<0.0001); and, for extracorporeal cardiopulmonary resuscitation (ECPR), lower ECMO flow rates at 24 hours (3.5 liters per minute [LPM] versus 3.7 LPM, p=0.01).

CONCLUSIONS

ECMO mostly remains in CTICUs though a minority is associated with cardiac surgery. Statistically significant but clinically minor differences in on-ECMO metrics were observed across ICU types.

Cochrane's risk of bias tool for non-randomized studies (ROBINS-I) is frequently misapplied: A methodological systematic review

OBJECTIVES

We aimed to review how 'Risk of Bias In Non-randomized Studies-of Interventions' (ROBINS-I), a Cochrane risk of bias assessment tool, has been used in recent systematic reviews.

STUDY DESIGN AND SETTING

Database and citation searches were conducted in March 2020 to identify recently published reviews using ROBINS-I. Reported ROBINS-I assessments and data on how ROBINS-I was used were extracted from each review. Methodological quality of reviews was assessed using AMSTAR 2 ('A MeaSurement Tool to Assess systematic Reviews').

RESULTS

Of 181 hits, 124 reviews were included. Risk of bias was serious/critical in 54% of assessments on average, most commonly due to confounding. Quality of reviews was mostly low, and modifications and incorrect use of ROBINS-I were common, with 20% reviews modifying the rating scale, 20% understating overall risk of bias, and 19% including critical-risk of bias studies in evidence synthesis. Poorly conducted reviews were more likely to report low/moderate risk of bias (predicted probability 57% [95% CI: 47-67] in critically low-quality reviews, 31% [19-46] in high/moderate-quality reviews).

CONCLUSION

Low-quality reviews frequently apply ROBINS-I incorrectly, and may thus inappropriately include or give too much weight to uncertain evidence. Readers should be aware that such problems can lead to incorrect conclusions in reviews.

The impact of trainees' working hour regulations on outcome in CABG and valve surgery in the State of New York

BACKGROUND AND AIM

In 2011, the Accreditation Council for Graduate Medical Education (ACGME) restricted the first-year residents' duty-hour to less than 16-hour shifts, decreased the maximum shift duration for senior residents, and increased minimum time off after on-call duties. Whether these changes may have impacted the outcomes in cardiac surgery remains unclear.

METHODS

We performed a difference-in-difference analysis of the New York State Cardiac Surgery Reporting System data in 2004-2006 (before the duty-hour policies change) and 2014-2016 (after the change). We evaluated differences in 30-day risk-adjusted mortality rates (RAMR) in coronary artery bypass grafting (CABG) and valve surgeries, stratifying data by hospital type: teaching hospitals (TH) versus nonteaching hospitals (NTH). NTH served as the control not affected by the duty-hour policies.

RESULTS

(1) The overall surgical volume for CABG surgery has decreased over time (37,645-24,991), while the volume for valve surgery remained similar (20,969-21,532); (2) TH had better short-term outcomes for CABG procedures during 2014-2016 (median RAMR: 1.01% vs. 1.55% in TH vs. NTH, respectively; p = .025) as well as for valve procedures during both 2004-2006 (5.16% vs. 7.49%, p = .020) and 2014-2016 (2.59% vs. 4.09%, p = .033); (3) at difference-in-difference analysis, trainees' duty-hour regulations were not associated with worsening short-term outcomes in both CABG (p = .296) and valve (p = .651) procedures performed in TH.

CONCLUSION

The introduction of the 2011 trainees' duty-hour regulations was not associated with worse short-term outcomes for CABG and valve surgery performed in the State of NY by TH.

Venoarterial Extracorporeal Membrane Oxygenation for Postcardiotomy Shock-Analysis of the Extracorporeal Life Support Organization Registry

OBJECTIVES

Refractory postcardiotomy cardiogenic shock complicating cardiac surgery yields nearly 100% mortality when untreated. Use of venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock has increased worldwide recently. The aim of the current analysis was to outline the trends in use, changing patient profiles, and in-hospital outcomes including complications in patients undergoing venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock.

DESIGN

Analysis of extracorporeal life support organization registry from January 2010 to December 2018.

SETTING

Multicenter worldwide registry.

PATIENTS

Seven-thousand one-hundred eighty-five patients supported with venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock.

INTERVENTIONS

Venoarterial extracorporeal membrane oxygenation.

MEASUREMENTS AND MAIN RESULTS

Hospital death, weaning from extracorporeal membrane oxygenation, hospital complications. Mortality predictors were assessed by multivariable logistic regression. Propensity score matching was performed for comparison of peripheral and central cannulation for extracorporeal membrane oxygenation. A significant trend toward more extracorporeal membrane oxygenation use in recent years (coefficient, 0.009; p < 0.001) was found. Mean age was 56.3 ± 14.9 years and significantly increased over time (coefficient, 0.513; p < 0.001). Most commonly, venoarterial extracorporeal membrane oxygenation was instituted after coronary artery bypass surgery (26.8%) and valvular surgery (25.6%), followed by heart transplantation (20.7%). Overall, successful extracorporeal membrane oxygenation weaning was possible in 4,520 cases (56.4%), and survival to hospital discharge was achieved in 41.7% of cases. In-hospital mortality rates remained constant over time (coefficient, -8.775; p = 0.682), whereas complication rates were significantly reduced (coefficient, -0.009; p = 0.003). Higher mortality was observed after coronary artery bypass surgery (65.4%), combined coronary artery bypass surgery with valve (68.4%), and aortic (69.6%) procedures than other indications. Lower mortality rates were observed in heart transplantation recipients (46.0%). Age (p < 0.001), central cannulation (p < 0.001), and occurrence of complications while on extracorporeal membrane oxygenation were independently associated with poorer prognosis.

CONCLUSIONS

The analysis confirmed increased use of venoarterial extracorporeal membrane oxygenation for postcardiotomy cardiogenic shock. Mortality rates remained relatively constant over time despite a decrease in complications, in the setting of supporting older patients.

Veno-Arterial Extracorporeal Life Support in Heart Transplant and Ventricle Assist Device Centres. Meta-analysis

Aims

Because reported mortality on veno‐arterial (V‐A) extracorporeal life support (ECLS) substantially varies between centres, the aim of the current analysis was to assess the outcomes between units performing heart transplantation and/or implanting ventricular assist device (HTx/VAD) vs. non‐HTx/VAD units in patients undergoing V‐A ECLS for cardiogenic shock.

Methods and results

Systematic search according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses was performed using PubMed/MEDLINE databases until 30 November 2019. Articles reporting in‐hospital/30‐day mortality and centre's HTx/VAD status were included. In‐hospital outcomes and long‐term survival were analysed in subgroup meta‐analysis. A total of 174 studies enrolling n = 13 308 patients were included with 20 series performed in non‐HTx/VAD centres (1016 patients, 7.8%). Majority of patients underwent V‐A ECLS for post‐cardiotomy shock (44.2%) and acute myocardial infarction (20.7%). Estimated overall in‐hospital mortality was 57.2% (54.9–59.4%). Mortality rates were higher in non‐HTx/VAD [65.5% (59.8–70.8%)] as compared with HTx/VAD centres [55.8% (53.3–58.2%)], P < 0.001. Estimated late survival was 61.8% (55.7–67.9%) without differences between non‐HTx/VAD and HTx/VAD centres: 66.5% (30.3–1.02%) vs. 61.7% (55.5–67.8%), respectively (P = 0.797). No differences were seen with respect to ECLS duration, limb complications, and reoperations for bleeding, kidney injury, and sepsis. Yet, weaning rates were higher in HTx/VAD vs. non‐HTx/VAD centres: 58.7% (56.2–61.1%) vs. 48.9% (42.0–55.9%), P = 0.010. Estimated rate of bridge to heart transplant was 6.6% (5.2–8.3%) with numerical, yet not statistically significant, difference between non‐HTx/VAD [2.7% (0.8–8.3%)] as compared with HTx/VAD [6.7% (5.3–8.6%)] (P = 0.131).

Conclusions

Survival after V‐A ECLS differed according to centre's HTx/VAD status. Potentially different risk profiles of patients must be taken account for before definite conclusions are drawn.

Iatrogenic Extracorporeal Membrane Oxygenator Rupture: Successful Management of a Unique Crisis

We are presenting a case of successful resuscitation during accidental rupture of a venoarterial extracorporeal membrane oxygenator after surgical pulmonary embolectomy. This article reports a rare complication related to the mechanical circulatory support and its successful management.

Left Ventricle Unloading with Veno-Arterial Extracorporeal Membrane Oxygenation for Cardiogenic Shock. Systematic Review and Meta-Analysis

During veno-arterial extracorporeal membrane oxygenation (VA-ECMO), the increase of left ventricular (LV) afterload can potentially increase the LV stress, exacerbate myocardial ischemia and delay recovery from cardiogenic shock (CS). Several strategies of LV unloading have been proposed. Systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement included adult patients from studies published between January 2000 and March 2019. The search was conducted through numerous databases. Overall, from 62 papers, 7581 patients were included, among whom 3337 (44.0%) received LV unloading concomitant to VA-ECMO. Overall, in-hospital mortality was 58.9% (4466/7581). A concomitant strategy of LV unloading as compared to ECMO alone was associated with 12% lower mortality risk (RR 0.88; 95% CI 0.82–0.93; p < 0.0001; I² = 40%) and 35% higher probability of weaning from ECMO (RR 1.35; 95% CI 1.21–1.51; p < 0.00001; I² = 38%). In an analysis stratified by setting, the highest mortality risk benefit was observed in case of acute myocardial infarction: RR 0.75; 95%CI 0.68–0.83; p < 0.0001; I² = 0%. There were no apparent differences between two techniques in terms of complications. In heterogeneous populations of critically ill adults in CS and supported with VA-ECMO, the adjunct of LV unloading is associated with lower early mortality and higher rate of weaning.