Left ventricular unloading during extracorporeal life support for myocardial infarction with cardiogenic shock: surgical venting versus Impella device.

Objectives: Patients in cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO) may experience severe complications from reduced left ventricular (LV) unloading and increased cardiac afterload. These effects are usually modified by adding a percutaneous direct Impella vent or surgical LV vent on top of VA-ECMO in selected patients. However, direct comparisons between 2 LV unloading strategies in patients with cardiogenic shock due to myocardial infarction are lacking. Therefore, we sought to investigate the impact of these 2 different approaches.

Methods: We enrolled 112 patients treated with an Impella or surgical LV vent during VA-ECMO support between January 2014 and February 2020. The primary endpoint was 30-day mortality. Secondary endpoints included rates of myocardial recovery or transition to durable mechanical circulatory support. Additionally, we assessed adverse events such as peripheral ischaemic complications requiring intervention, sepsis and ischaemic stroke.

Results: At 30 days, 38 patients in the Impella group (54%) and 26 patients in the surgical LV vent group (63%) had died (relative risk with Impella 0.78, 95% confidence interval 0.47-1.30; P = 0.35). Impella group and the surgical LV vent group differed significantly with respect to the secondary end points including rates of myocardial recovery (24% and 7%, respectively; P = 0.022) and rates of durable mechanical circulatory support (17% and 42%, P = 0.012). Complication rates were not statistically different between the 2 groups.

Conclusions: The use of Impella device as therapeutic unloading therapy during VA-ECMO did not significantly reduce 30-day mortality compared to surgical LV vent in patients with cardiogenic shock due to acute myocardial infarction.