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

Abstract

Background: Postcardiotomy cardiogenic shock (PCS) that is refractory to inotropic support remains a major concern in cardiac surgery and is almost universally fatal unless treated with mechanical support. While reported mortality rates on ECMO vary from center to center, aim of the current report is assess if the outcomes differ between centres according to volume and heart transplantation status. Methods: A systematic search was performed according to PRISMA statement using PubMed/Medline databases between 2010 and 2018. Relevant articles were scrutinized and included in the meta-analysis only if reporting inhospital/30-day mortality and heart transplantation status of the centre. Paediatric and congenital heart surgeryrelated studies along with those conducted in the setting of veno-venous ECMO for respiratory distress syndrome were excluded. Differences were assessed by means of subgroup meta-analysis and meta-regression. Results: Fifty-four studies enrolling N = 4421 ECMO patients were included. Of those, 6 series were performed in non-HTx centres (204 pts.;4.6%). Overall 30-day survival (95% Confidence Intervals) was 35.3% (32.5-38.2%) and did not statistically differ between non-HTx: 33.3% (26.8-40.4%) and HTx centres: 35.7% (32.7-38.8%); P interaction = 0.531. There was no impact of centre volume on survival as well: ß coef = 0.0006; P = 0.833. No statistical differences were seen between HTx and non-HTx with respect to ECMO duration, limb complications, reoperations for bleeding, kidney injury and sepsis. There were however significantly less neurological complications in the HTx as compared to non-HTx centres: 11.9% vs 19.5% respectively; P = 0.009; an inverse relationship was seen for neurologic complications in centres performing more ECMOs annually ß coef = − 0.0066; P = 0.031. Weaning rates and bridging to HTx and/or VADs were higher in HTx facilities. Conclusions: There was no apparent difference in survival after ECMO implantation for refractory PCS according to centre's ECMO volume and transplantation status. Potentially different risk profiles of patients in these centres must be taken account for before definite conclusions are drawn.

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

“…Out of the 174 studies included, 154 were conducted in HTx/VAD units, and as a result, 92.2% of reported patients were treated there. This is similar to findings from analysis focused exclusively on post‐cardiotomy patients 22 . Overrepresentation of reports on V‐A ECLS from HTx/VAD centres seem to apply to different aetiologies of CS.…”

“…The main finding of present analysis is that 30 day/in‐hospital weaning and survival rates were significantly lower in non‐HTx/VAD as compared with HTx/VAD centres. This is in contrast to results of analysis focusing exclusively on post‐cardiotomy patients where no differences were observed 22 . Different risk profiles of post‐cardiotomy and non‐post‐cardiotomy patients must be taken to account.…”

“…On the other hand, in the post-cardiotomy setting, respective estimated rates were 3.5% (1.8-6.6%) and 4.3% (2.8-6.5%). 22 We propose an algorithm of patient management in the setting of CS managed with V-A ECMO with respect to patient referral to HTx/VAD performing centre ( Figure 6) in which the patient, if stable, may be a candidate for referral between 4 and 7 days of treatment.…”

“…This is in contrast to results of analysis focusing exclusively on post-cardiotomy patients where no differences were observed. 22 Different risk profiles of post-cardiotomy and non-post-cardiotomy patients must be taken to account. V-A ECLS after adult cardiac surgery had been associated with higher risk of in-hospital mortality compared with other indications (supplementary references 42 and 159).…”

“…Indeed, in the mixed aetiology population, overall 30-day survival was 42.8% and in the post-cardiotomy setting, as shown in previous meta-analysis, it was estimated at 35.3%. 22 Negative prognostic effect of post-cardiotomy on survival may be explained by the impact of the underlying cardiac disease with its accompanying risk factors as well as the extent of the surgical procedure and its potential complications. In acute settings such as post-cardiotomy shock, V-A ECLS is mainly instituted as a temporizing measure and a bridge to recovery rather than bridge to VAD or heart transplantation, which are indeed more frequent therapeutic options in chronic heart failure patients (3,4, and supplementary reference 158).…”