Feasibility of Early Mechanical Support During Mechanical Reperfusion of Acute Myocardial Infarct Cardiogenic Shock.

Mechanical reperfusion for acute myocardial infarction cardiogenic shock (AMICS) has a class I A indication in both the American and European guidelines (1). Unfortunately, over the past 20 years, little progress has been made in improving outcomes since the pivotal SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) trial was conducted (2). The recent Food and Drug Administration approval of the Impella (Abiomed, Danvers, Massachusetts), a percutaneous micro-axial flow mechanical circulatory support (MCS) device, has provided powerful, readily available hemodynamic support during reperfusion therapy of AMICS. Five centers in the metro Detroit area (St. Joseph Mercy Pontiac, William Beaumont Royal Oak, William Beaumont Troy, Henry Ford Detroit, and the Detroit Medical Center) have performed a pilot feasibility analysis to determine whether early routine use of MCS with Impella is possible and to see whether impact on outcomes could be tracked. Between July 1, 2016, and September 26, 2016, the centers agreed to treat all patients with AMICS in a similar, mutually agreed protocol. To date, 15 patients have been treated. The goal of therapy is to initiate hemodynamic support as soon as possible after catheterization laboratory arrival. The U.S. Pella investigators have shown that outcomes are improved when MCS is initiated before reperfusion (3). For this reason, PCI was performed after MCS was initiated. Cardiogenic shock was defined similarly to the SHOCK trial (4). Mean age was 68.6 years (44 to 87 years), 60% were male, and 64% were diabetic. Qualifying systolic blood pressure was 80.8 11.7 mm Hg, with an admission lactate of 5.4 3.7. 73% of patients required support with inotropes or intra-aortic balloon pump before intervention. Two patients required active cardiopulmonary resuscitation during Impella placement before reperfusion. The time from admission to initiation of hemodynamic support was 61 min. Reperfusion was successful in all patients, and Thrombolysis In Myocardial Infarction (TIMI) flow grade III was present in 86% of patients after percutaneous coronary intervention (PCI). Cardiac power output (CPO) was 0.57 pre-support and 0.96 post-support (p < 0.0001). All patients left the catheterization laboratory with a CPO $0.6 W (5). Hospital survival was 80%. Although only preliminary, initial experience suggests that rapid door-to-support times are feasible. This approach results in the rapid reversal of the shock state in most patients, allowing operators to obtain TIMI flow grade III rates comparable to those in patients with non-shock ST-segment elevation MI and may improve survival. Given these encouraging pilot data, a large formal quality initiative entitled the Detroit Cardiogenic Shock Initiative has been launched.