Early door-to-unloading and in-hospital mortality in patients with non-acute coronary syndrome cardiogenic shock undergoing Impella introduction.

Background: The association between early Impella (Abiomed, Inc., Danvers, MA, USA) introduction and outcomes in patients with non-acute coronary syndrome (ACS) cardiogenic shock remains unclear. This study aimed to examine whether early Impella introduction leads to better outcomes in patients with non-ACS.

Methods: Patients with non-ACS cardiogenic shock treated with Impella (n = 731), who were registered in the Japanese Registry for Percutaneous Ventricular Assist Devices, were categorized based on the time from admission to Impella introduction (door-to-unloading time): groups A (within 6 h), B (6-24 h), C (1-3 days), and D (>3 days). The primary endpoint was in-hospital mortality; the secondary endpoints included left ventricular ejection fraction (LVEF) at Impella removal and adverse event frequency.

Results: In-hospital mortality rates increased with delayed Impella introduction: 25.9 %, 34.2 %, 37.8 %, and 45.0 % in groups A, B, C, and D, respectively, with a significant difference between groups A and D (p < 0.001). The LVEF at Impella removal was significantly higher in group A than in group D [46 (35-57)% vs. 36 (26-50)%, p = 0.01]. Group D was an independent prognostic factor for in-hospital mortality compared with group A in all cohorts [odds ratio (OR), 1.98; 95 % confidence interval (CI), 1.01-3.91; p = 0.04] and in patients with myocarditis (OR, 2.87; 95 % CI, 1.06-7.80; p = 0.04).

Conclusions: Early Impella introduction in patients with non-ACS cardiogenic shock is associated with lower in-hospital mortality, especially in those with myocarditis.