Treatment with Impella and veno-arterial extracorporeal membrane oxygenation during cardiac arrest on survival in a multicenter cohort

Background

International organisations advocate the use of extracorporeal cardio-pulmonary resuscitation (ECPR) with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in selected patients with therapy-refractory cardiac arrest [1–3]. Although VA-ECMO allows for full circulatory support, it is inherent to increased left ventricular (LV) pressure due to retrograde aortic perfusion, which may hamper myocardial recovery and aggravate pulmonary oedema. In order to mitigate these negative sequelae, adjunct LV unloading with an Impella microaxial flow pump may be considered. The effects of concomitant treatment with VA-ECMO and Impella (ECMELLA) in patients with therapy-refractory cardiac arrest due to acute myocardial infarction (AMI) remains unclear.

Objectives

To the best of our knowledge this is the first study to investigate whether treatment with ECMELLA is associated with improved 30-day mortality rate in patients with therapy-refractory cardiac arrest caused by AMI, compared to treatment with VA-ECMO alone.

Methods

Patients treated with ECMELLA were propensity score (PS)-matched to patients receiving VA-ECMO based on age, electrocardiogram (ECG) rhythm, cardiac arrest location (out-of-hospital or in-hospital) and Survival After Veno-Arterial ECMO (SAVE) score. Cox proportional-hazard and Poisson regression models were used to analyse 30-day mortality rate (primary outcome), hospital and intensive care unit (ICU) length of stay (LOS) (secondary outcomes). Multiple sensitivity analyses on patient demographics and cardiac arrest parameters were performed.

Results

95 adult patients from three tertiary care centers were included, out of whom 34 pairs were PS-matched. ECMELLA treatment was associated with 47% decreased 30-day mortality risk [95% Confidence Interval (CI) 0.31–0.91, P=0.021], 71% prolonged hospital [95% CI 1.50–1.95, P<0.001] and 81% prolonged ICU LOS [95% CI 1.57–2.08, P<0.001]. Kaplan-Meier analyses (Figure 1) and multiple sub-group analyses (age, sex, initial ECG rhythm, Charlson comorbidity index, body mass index, SAVE score, cardiac arrest location, lactate and pH levels) confirmed survival benefits in the ECMELLA group. Especially patients with prolonged low-flow time and high initial lactate benefited from ECMELLA therapy. Moreover, LV ejection fraction strongly improved in the ECMELLA group between ICU admission and ICU discharge from 15% to 40%, compared 15% and 20% in the VA-ECMO group.

Conclusion

In this multicenter propensity score-matched cohort of patients with ECPR during therapy-refractory cardiac arrest caused by AMI, treatment with ECMELLA was associated with improved survival compared to treatment with VA-ECMO alone. These findings support current guideline recommendations on early evaluation of ECPR in well selected patients with therapy-refractory cardiac arrest. A clinical trial is urgently needed to further evaluate the role of LV unloading in patients with therapy-refractory cardiac arrest.

Funding Acknowledgement

Type of funding sources: None.

P5249Comprehensive invasive and non-invasive assessment of coronary artery lesions with and without hemodynamic significance

Background

There is limited knowledge about specific morphological parameters beyond the degree of stenosis to further characterize hemodynamically relevant coronary lesions.

Objective

The goal of this study was to identify certain morphological or molecular characteristics that distinguish hemodynamically significant from non-significant coronary lesions using various invasive and non-invasive measures.

Methods

This clinical study included patients with symptoms suggestive of CAD who underwent native T1-weighted CMR and gadofosveset-enhanced CMR as well as invasive coronary angiography between 2015 and 2016. OCT of the culprit vessel to determine the plaque type was performed in a subset of patients. Functional relevance of all lesions was examined using quantitative flow reserve (QFR-Angio). Hemodynamically significant lesions were defined as lesions with a QFR <0.8. Signal intensity (contrast-to-noise ratios; CNRs) on native T1-weighted CMR and gadofosveset-enhanced CMR was defined as a measure for intraplaque hemorrhage and endothelial permeability respectively.

Results

Overall 13 patients (n=28 coronary segments) were included, whose invasive coronary angiograms projections were eligible for QFR analysis. Segments containing lesions with a QFR <0.8 (n=9) were associated with significantly higher signal enhancement on Gadofosveset-enhanced CMR as compared to segments containing a hemodynamically non-relevant lesions (lesion-QFR>0.8; n=19) (7.0±4.9 vs. 3.0±2.6; p=0.02). No differences in signal enhancement were seen on native T1-weighted CMR (2.1±4.3 vs. 3.3±4.1; p=0.24). 66,7% (4 out of 6) of all vulnerable plaque and 33.3% (2 out of 6) of all non-vulnerable plaque (fibroatheroma) as assessed by OCT were hemodynamically significant lesions.

Conclusion

The findings of this small feasibility study suggest that hemodynamically significant lesions are more advanced and associated with a higher grade of endothelial permeability while the presence of intraplaque hemorrhage may not be associated with hemodynamically relevant coronary lesions.