Improved Outcomes May Be Associated With the Use of Shock Protocols: Updates From the National Cardiogenic Shock Initiative

Background:
The National Cardiogenic Shock Initiative is a single-arm, prospective, multicenter study to assess outcomes associated with the use of early mechanical circulatory support (MCS) in patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMICS) treated with percutaneous coronary intervention (PCI).

Methods:
Between May 2016 and February 2019, 35 sites participated in the study. All centers agreed to treat patients with AMICS using a standard protocol emphasizing invasive hemodynamic monitoring and rapid initiation of MCS. Inclusion and exclusion criteria mimicked those of the ‘SHOCK’ trial with an additional exclusion criteria being use of intra-aortic balloon pump counter-pulsation prior to MCS.

Results:
A total of 171 consecutive patients were enrolled. Patients had an average age of 63 +/- 12 years, 77% were male, 72% were admitted with AMICS. Prior to MCS, 82% of patients were on vasopressors or inotropes, 42% of the cohort had cardiac arrest; 32% had in-hospital cardiac arrest, 20% had witnessed out of hospital cardiac arrest and 10% were under active cardiopulmonary resuscitation during MCS implantation. In accordance with the protocol, 74% of patients had a MCS device inserted prior to PCI and 92% had right heart catheterization. 77% of patients presented with STEMI with average door to support times of 97 +/-104 minutes and door to balloon times of 107 +/-148 minutes. Survival to discharge was 72%. Creatinine ≥1.5 (≥1.5=77% survival vs. <1.5=57.5% survival; p<0.01), lactate >4 (>4=75% survival vs <4=60% survival; p<0.01) and age ≥75 years were predictors of mortality on admission. Lactate and cardiac power output measurements at 12-24 hours reliably predicted overall mortality post index procedure.

Conclusions:
In contemporary practice use of a shock protocol may be associated with improved outcomes.