Clinical Significance of Spontaneous Echo Contrast on Extracorporeal Membrane Oxygenation.

Background: Spontaneous echo contrast (SEC) is known to be a predisposition to thromboembolism and cerebrovascular accident. The aim of this study was to investigate the risk factors and the consequences of SEC in patients who were placed on venoarterial extracorporeal membrane oxygenation (VA-ECMO) because of cardiogenic shock.

Methods: Between January 2011 and December 2014, 98 patients underwent the insertion of VA-ECMO because of cardiogenic shock in our institution. Transthoracic and transesophageal echocardiography was performed and interpreted by National Board of Echocardiography certified cardiologists. Patients were divided into 2 groups based on the presence or absence of SEC. Clinical data, echocardiographic measurements, and outcomes were compared between the 2 groups.

Results: Of the 98 patients, 22 patients (22%) had SEC on echocardiography. Patients in the SEC group had a lower ejection fraction (8.0% versus 29%; p < 0.001), a lower pulsatility index (defined by [systolic blood pressure - diastolic blood pressure]/mean blood pressure) while receiving ECMO (0.13 ± 0.14 versus 0.26 ± 0.22; p = 0.009). The SEC group had a higher rate of intracardiac thrombus (46% versus 13%; p = 0.002) and stroke (36% versus 7.9%; p = 0.002). On univariate analysis, intracardiac thrombus, SEC, and low pulsatility were significant risk factors for the development of stroke. On multivariate analysis, SEC was the only independent risk factor for stroke.

Conclusions: SEC on VA-ECMO resulted in an increased risk of intracardiac thrombus and stroke. Maintaining pulsatility while the patient is on ECMO may result in a decreased chance of developing SEC and stroke.