Left Ventricular Ejection Fraction in Cardiac Arrest Survivors Treated With Extracorporeal Cardiopulmonary Resuscitation

Extra-hospital cardiac arrest is a major public health problem, with approximately 46,000 cases per year. Nearly 71% of the patients for whom resuscitation was initiated did not present a return of spontaneous circulation on scene and only 29% were transported alive to the hospital. In this context, extracorporeal cardiopulmonary resuscitation (ECPR) by veno-arterial extracorporeal membrane oxygenation has been developed as a second line of treatment according to the latest international guidelines. The selection of eligible patients as well as the timing of initiation of ECPR has long been controversial, but expert recommendations have recently been published.

After an out-of-hospital cardiac arrest of cardiological cause, an early ventricular dysfunction has been previously described, more particularly in hemodynamically unstable patients. This dysfunction was associated with greater early in-hospital mortality. There are few data on the medium-term course of left ventricular dysfunction and the largest study addressing this question showed that the severity of left ventricular involvement was associated with greater long-term morbidity and mortality. However, it also found that left ventricular ejection fraction was partially reversible in 29% of the study population.

It seems so far, the medium-term evolution of left heart dysfunction had not been described in the context of refractory extra-hospital cardiac arrest treated by ECPR. However, these patients are particularly severe, hemodynamically unstable and potentially at risk of developing long-term sequelae.

The research focuses on the evolution of left ventricular function at 28 and 90 days after an out-of-hospital refractory cardiac arrest treated with ECPR as well as describing the survival rate at 28 and 90 days for these patients.

The expected results are to demonstrate that the left ventricular function, described through the left ventricular ejection fraction, is seriously affected in the population studied without signs of reversibility. These patients would therefore need close cardiological follow-up and to be integrated into a dedicated care pathway.

Inclusion criteria

• Implementation of an extracorporeal membrane oxygenation (ECMO) following an acute coronary syndrome (ACS) defined for the purposes of the study by the existence of at least one of the following criteria: ST segment elevation or depression on the electrocardiogram associated with chest pain and elevated plasma troponin levels; a coronary angiography showing at least one significant coronary lesion and/or having required revascularization. Confirmation of an ischemic etiology by post-mortem examination. A coronary lesion is considered significant if it is described by the cardiologist as: acute and responsible for a reduction in the caliber of the artery strictly greater than 70% and less than 99% for a severe stenosis, and 100% for a complete stenosis.
• Patients hospitalized at Necker Hospital for pre-hospital cardiac arrest between January 1, 2015 and October 31, 2019.
• Sending to living patients of the study information note, a period of one month is given to the patients to oppose the use of their data for the study.

Exclusion criteria

• Extracorporeal membrane oxygenation implementation outside the context of refractory out-of-hospital cardiac arrest
• In-hospital cardiac arrests
• Obvious non-cardiological cause of cardiac arrest
• Cardiac arrests unrelated to acute coronary syndrome
• Cardiac arrests for which no etiology has been found
• Patients opposed to the use of their data