National Cardiogenic Shock Initiative

This study evaluates the use of early mechanical circulatory support in patients presenting with acute myocardial infarction and cardiogenic shock. Patients are treated according to the National Cardiogenic Shock Initiative protocol, which emphasizes early identification of cardiogenic shock and rapid delivery of mechanical circulatory support based on invasive hemodynamics. All patients treated in this manner are enrolled in the National Cardiogenic Shock registry.

Acute myocardial infarction complicated by cardiogenic shock (AMICS) is a deadly condition with a historical in-hospital survival of only 50%. To date, the only therapy proven to benefit patients in AMICS using data from randomized control trials has been early mechanical reperfusion. Accordingly, current American and European guidelines confer a class IB indication for reperfusion therapy in the setting of AMICS. Unfortunately, little progress has been made on improving survival with subsequent therapies, including intra-aortic balloon pump counter-pulsation (IABP). This lack of progress is worrisome since the incidence of AMICS appears to be increasing.

With the FDA approval of Impella (Abiomed, Danvers, MA) in AMICS, a powerful new tool has become available for hemodynamic support. Impella is a transcatheter axial flow pump, delivered percutaneous, with the ability to provide 2.5 to 4.0 liters/minute of forward flow. The device should provide sufficient forward cardiac flow to support vital organs in the majority of patients who present with AMICS. Since Impella is the only percutaneous temporary ventricular support device approved as safe and effective for use in AMICS, the use of the device has steadily grown. Unfortunately, there is little data available to providers as to the best practice patterns associated with the delivery and use of Impella in AMICS.

Using the most up-to-date research, a treatment algorithm for AMICS was developed and subsequently implemented as a quality improvement initiative throughout southeast Michigan. Patient information was gathered by each of the sites and collected in a retrospective registry. Outcomes and results were shared during quarterly meetings and concluded with a 41-patient pilot feasibility study. This initial pilot study revealed a 76% survival to discharge, a significant improvement compared to prior historical controls.

Given the promising outcomes, leaders from around the world have implemented the treatment algorithm in their local clinical practices with similar results. The investigators have therefore launched the National Cardiogenic Shock Initiative (NCSI). The aim of the NCSI is to bring together experienced centers across the nation who are experts in mechanical reperfusion therapies and have a large experience with the use of mechanical circulatory support devices to systematize care in AMICS.

Our goal is to dramatically decrease the duration patients remain in cardiogenic shock and attempt to decrease total usage and duration of vasopressors and ionotropic agents. The investigators aim to further demonstrate that rapid delivery of mechanical circulatory support will improve hemodynamics, reverse the spiraling neuro-hormonal cascade associated with cardiogenic shock, allowing clinicians to decrease use of vasopressors and inotropic agents and ultimately improve survival.

Healthcare systems that have agreed to adopt the NCSI treatment algorithm are being asked to participate in this prospective registry so that patient outcomes can be analyzed. Participating investigators will be asked to voluntarily provide data from patients completing the treatment algorithm to be included in the NCSI Registry.

Eligibility Criteria:
Registry Inclusion Criteria:

1. Symptoms of acute myocardial infarction (AMI) with ECG and/or biomarker evidence of S-T elevation myocardial infarction (STEMI) or non-S-T elevation myocardial infarction (NSTEMI)
2. Cardiogenic shock is defined as the presence of at least two of the following:

   1. Hypotension (systolic blood pressure ≤90 mm Hg, or inotropes/vasopressors to maintain systolic blood pressure ≥90 mmHg)
   2. Signs of end organ hypoperfusion (cool extremities, oliguria or anuria, or elevated lactate levels)
   3. Hemodynamic criteria represented by a cardiac index of \<2.2 L/min/m2 or a cardiac power output ≤0.6 watts.
3. Patient is supported with an Impella
4. Patient undergoes PCI

Registry Exclusion Criteria:

1. Evidence of Anoxic Brain Injury
2. Unwitnessed out of hospital cardiac arrest or any cardiac arrest in which return of spontaneous circulation (ROSC) is not achieved within 30 minutes
3. IABP placed prior to Impella
4. Septic, anaphylactic, hemorrhagic, and neurologic causes of shock
5. Non-ischemic causes of shock/hypotension (pulmonary embolism, pneumothorax, myocarditis, tamponade, etc.)
6. Active bleeding for which mechanical circulatory support is contraindicated
7. Recent major surgery for which mechanical circulatory support is contraindicated
8. Mechanical complications of AMI (acute ventricular septal defect (VSD) or acute papillary muscle rupture)
9. Known left ventricular thrombus for which mechanical circulatory support is contraindicated
10. Mechanical aortic prosthetic valve
11. Contraindication to intravenous systemic anticoagulation