Why is this study important?

• The role of Mechanical Circulatory Support (MCS) in Acute Myocardial infarction-associated Cardiogenic Shock (AMICS) is unclear, with mixed results in prior registries and trials.
• The DANGER SHOCK trial was conducted to evaluate the efficacy of the transvalvular axial flow device, Impella CP (Abiomed, Danvers, Washington) in treating patients with acute myocardial infarction carcinogenic shock (AMICS) secondary to ST-elevation myocardial infarction (STEMI), undergoing emergency percutaneous coronary intervention (PCI).

What question was this study supposed to answer?

Is the transvalvular axial flow device Impella CP beneficial in AMICS?

What did the study show?

• There were 355 patients in the study, 79% male, median age of 67, enrolled in Denmark, Germany, and the UK.
• 179 patients received the Impella CP and standard care, while 178 were randomized to standard care. All patients were revascularized and 84% of patients were randomized before PCI, with a median time of 4 hours from STEMI onset. In the Impella CP arm, the majority received the device before revascularization.
• Shock characteristics were a median SBP < 89 mmHg, ejection fraction (EF) <25 %, and lactate 4.5 mmol/L). 55% of patients were SCAI Shock class C, and the remainder Class D and E. Left anterior descending artery (LAD) or Left Main were the culprit vessels in 72% of patients and 72% had more than one diseased vessel.
• At the primary endpoint of death at 180 days, there was a 13% reduction in mortality in those who received Impella CP and standard care with a number needed to treat (NNT) of 8. Mortality was 45.8% in the Impella CP group vs 58.5% in the standard care group (hazard ratio, 0.74; 95% confidence interval [CI], 0.55 to 0.99; P = 0.04). Greater benefit was seen in those with an SBP < 63 mmHg and revascularization of more than one vessel.
• There was a higher rate of complications in the Impella CP arm with bleeding, vascular complications, sepsis, and renal replacement therapy.
• The results are not generalizable as comatose cardiac arrest patients, those with mechanical complications, and right ventricular (RV) failure were excluded.

 
Take Home Point

In contrast to other mechanical circulatory support (MCS) devices, selective use of the transvalvular axial flow device in AMICS patients is associated with a 13% decrease in mortality at six months.