Cardiology Corner: New Post Cardiac Arrest Guidelines

 

Cardiology Corner: New Post Cardiac Arrest Guidelines

Rob Orman MD and Amal Mattu MD

PEARLS

• Patients with ROSC after out-of-hospital should have risk stratification to determine possible benefit of cath.

• An initial rhythm of ventricular fibrillation is a good predictor of a primary cardiac event. These patients benefit from cath.

• Shocks and epinephrine can induce dramatic ST changes, including ST elevation, on the subsequent EKG

• In July 2015, the American College of Cardiology released their algorithm on managing patients post-cardiac arrest.

• Rab, T et al. Cardiac Arrest: A Treatment Algorithm for Emergent Invasive Cardiac Procedures in the Resuscitated Comatose Patient. J Am Coll Cardiol. 2015 Jul 7;66(1):62-73. OPEN ACCESS LINK

• This article introduces the concept of risk stratification in post out-of-hospital cardiac arrest patients. Who will be best treated in the cath lab? The cath lab is not a magical cure. The only thing that will be done is to look for a coronary artery occlusion and open it. Every other aspect of resuscitation will be pushed aside. If the patient has sepsis, PE or dissection, they will not be receiving treatment for these. There is no team of critical care specialists working on that patient. The cardiologist is trying to do one thing only; open the vessel. If the arrest was not due to a primary cardiac event, you may be doing more harm by sending the patient to the cath lab.

• There are three important questions that need to be addressed prior to considering cath?

• Does the initial rhythm matter?

• Does the post-arrest EKG matter?

• Does the mental status matter?

• Does the initial rhythm matter? If the initial post-arrest rhythm was ventricular fibrillation, it is a very good predictor of a primary cardiac event. Sending this patient to the cath lab is a good idea. However, if the rhythm was PEA or asystole, you don’t know if it was primary cardiac event or another etiology. The initial rhythm does make a difference. A primary cardiac event will produce PEA or asystole only about 50% of the time.

• Does the post-arrest EKG matter? If the post-arrest EKG shows STEMI, it is a good predictor of a primary cardiac event and these patients should be sent to the cath lab. If the first EKG obtained after ROSC shows a non-ST elevation ACS, there is only a 33% chance that there is a vessel occlusion involved.

• Does the mental status matter? There is increasing literature showing that catheterization may improve outcome regardless of neurologic state. Don’t avoid sending a comatose patient to the cath lab as they may have a better outcome with cath.

• Shocks and epinephrine can induce dramatic ST changes, including ST elevation, on the subsequent EKG. In general, the changes due to shocks or epinephrine can last about 10 to 15 minutes. Get a 12-lead EKG after ROSC is achieved. If there is ST segment elevation, it may be unreliable due to the epinephrine. A repeat EKG approximately 15 minutes after the last dose of epinephrine may be more reliable.

• How do you know the patient has non-ST-elevation ACS? They may have been a PE or sepsis or overdose. This is where the risk stratification comes in. Look at the initial rhythm. If the initial rhythm is ventricular fibrillation in the field or in the ED, it is a pretty good predictor that the inciting event was a primary cardiac event and these patients are more likely to benefit from the cath lab. If there was any history of chest pain before the cardiac arrest, it is also a good predictor of a primary cardiac event. Unfortunately, we often don’t have this information available.

• There are several unfavorable resuscitation features. If the patient has any one of these ten unfavorable conditions, you should think twice before sending the patient to the cath lab. They may need additional resuscitation. You need to discuss these cases with the cardiologist.  These features include: unwitnessed arrest, initial rhythm that was not ventricular fibrillation, no bystander CPR, greater than 30 minutes to ROSC, ongoing CPR, pH <7.2, lactate>7, age >85, end stage renal disease and suspected  non-cardiac events such as a trauma.

• In 2013, an article was published indicating early cardiac catheterization was associated with improved survival in survivors of cardiac arrest without STEMI. However, the data was retrospective. It was not clear that it was catheterization that made the difference; it may have been the more intensive and attentive care received by post-catheterization patients. Cooling was also included in the protocol.

• Hollenbeck, RD et al. Early cardiac catheterization is associated with improved survival in comatose survivors of cardiac arrest without STEMI. Resuscitation. 2014 Jan;85(1):88-95. PMID: 23927955

• If your facility doesn’t have a cath lab, should you transfer the patient to a facility that does? Or should the patient be stabilized in the ICU and transferred later for cath? There is no good answer. There are no randomized studies that say that the time and risk of transfer is justified by the benefit of cath lab.

• If your patient has a post-arrest STEMI, you should try to transfer them as you would any other STEMI patient.

• If the patient has a post-arrest non-STEMI and lower risk for a culprit lesion, you should focus on resuscitating the patient. When the patient is stabilized, you can consider transfer.

• This paper does not address fibrinolytics. The guidelines don’t address post-arrest use of thrombolytics. If the patient has a post-arrest STEMI on 12-lead EKG and you will not have a cath lab available, you can  give fibrinolytics to the patient. However, if the patient has a post-arrest non-STEMI ACS, thrombolytics are not indicated.