Talking Tall Rounds®: Out-of-Hospital Cardiac Arrest

Podcast Transcript

Announcer:

Welcome to the Talking Tall Rounds Series, brought to you by the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute at Cleveland Clinic.

Amar Krishnaswamy, MD:

Good morning, everyone, and welcome to another edition of Cleveland Clinic's Tall Rounds. Pleasure to have you join us this morning for what I think will be a dynamic conversation and presentation on out-of-hospital cardiac arrest.

Amar Krishnaswamy, MD:

Of the many things that we all do, out-of-hospital cardiac arrest and taking care of these patients, I think, is truly a multidisciplinary effort all the way from, of course, out of the hospital and involving EMS, through the intensive care units and thereafter.

Amar Krishnaswamy, MD:

And these are often very difficult patients to manage medically and also brings up oftentimes very challenging conversations with patients and families. Looking forward to this session, we're going to start out with a case presentation by Zach, who is one of our fellows in heart failure.

Zachary Il'Giovine, MD:

Thank you, everyone, it's an honor to be here. I'm Zach Il'Giovine, one of the cardiovascular medicine fellows, actually one of the advanced heart failure fellows. I also have an interest in critical care. And I'd like to start with a case.

Zachary Il'Giovine, MD:

This is the case of a 64-year-old gentleman with hypertension and hyperlipidemia who was swimming with his family. When he came out of the pool, he was noted to be pale, diaphoretic, and complaining of severe chest discomfort that did not improve with rest. EMS was called, however, just prior to their arrival, the patient collapsed and was unresponsive. CPR was started immediately by his family and as EMS arrived the initial rhythm was found to be ventricular fibrillation. He received one shock and had a return of spontaneous circulation, and immediately post ROSC the patient was neurologically intact and able to answer questions. An EKG was obtained and the post ROSC EKG showed ST elevations in the inferior leads two, three and AVF with reciprocal change in AVL. Also, some non-specific ST-T wave changes in the lateral precordial leads. He was taken for coronary angiography, this is a shot of the left system. Here there is no culprit really identified, maybe some mild-moderate disease in the LAD, the disproportion of the circumflex looks aneurysmal.

Zachary Il'Giovine, MD:

Again, in another view, no clear culprit identified the LAD is a large wraparound vessel, and, again, you can see the aneurysmal portion of the circumflex. But the big thing here was on the right side, and so this is an angiography of his RCA. You can see 100% percent mid-RCA occlusion. The RCA was wired and you can see that it reveals a large dominant vessel. He underwent PCI to the proximal mid and distal portions of the vessel and had a very good result. And again, just a final shot here showing a good flow post revascularization.

Zachary Il'Giovine, MD:

After coronary angiography, he was transferred to the CICU in stable condition, both hemodynamically and was neurologically intact. Targeted temperature management was not indicated. Left and right ventricular functions were preserved. You can see, over the course of his time in the CICU, that he had a prominent troponin and CKMB leak. The ST elevations that were initially present had resolved post revascularization. He was continued on aspirin, Ticagrelor and a statin, and along with risk factor modification was ordered for cardiac rehabilitation. He was discharged without incident and continues to do well. Thank you.

Grant Reed, MD:

Good morning, everybody, thanks for having me. We're going to shift gears and build upon our great talks already and expand about what Dr. Whitman just talked about, as well as what Dr. Bajzer will be talking about, and specifically discuss the role of PCI in patients with out-of-hospital cardiac arrest.

Grant Reed, MD:

As we'll reinforce through a couple of talks today, the role of the cath lab is not just to do PCI in every patient that has an arrest. And as we'll discuss, it's not appropriate for everyone. There is a subset of patients that benefit, but defining that subset is very important. And although PCI is technically the same, patients with out-of-hospital arrest are often critically ill and unstable so there's a higher incidence of mechanical circulatory support either before or after PCI. The strategy really revolves around the decision to pursue catheterization in the first place and the timing of catheterization. And then if coronary artery disease is found, which is very common, if PCI should be formed in those patients.

Grant Reed, MD:

The decision about the timing of coronary angiography is really based on the type of arrest, which then leads to what we estimate the mechanism to be. And that's not always clear because unfortunately although our EMS team does a great job in getting a rhythm stripped for us in most patients, very rarely do we have a clear-cut cause. Maybe someone had crushing chest pain, they went down, and they were found to be in VF. Those are the patients for that we have a very clear, plausible explanation for ischemia being the cause. However, as Tom Beers mentioned, oftentimes patients are found with asystole or PEA and then after ROSC they have SD segment elevation. What is the real cause in those patients?

Grant Reed, MD:

The type of arrest guides us and we stratify based on the initial rhythm and then the pre and post-ECG. Patients with ST-segment elevation on their ECG prior to, or after ROSC, which is due to a presumed ischemic cause should undergo immediate coronary angiography. And those patients we treat as having an ST-segment elevation MI. Important though to recognize that not all post-arrest ST-segment elevation is coronary ischemia. Oftentimes these patients are hyperkalemic due to metabolic acidosis, they may have baseline ECG changes which are important to consider, but as we all appreciate the changes in acidosis can mimic ST-segment elevation MI, so very important to keep that in mind. There was an ECG of a patient with hyperkalemia and as the potassium rises due to acidosis this can be very hard to discern if this is due to coronary ischemia or not.

Grant Reed, MD:

But this is a case of someone who came in with a classic story. They were at home, had a witness arrest, had CPR done immediately. As you can see here, the initial ECG post-ROSC showed ST segment elevation in AVR, the anterior septal leads and just profound ST segment depressions. This is global myocardial ischemia and an injury pattern in someone that actually had left main disease. They were very unstable so an Impella was placed to support them, and they had bifurcation PCI done with a good result. And that patient was discharged home with full neurologic recovery.

Grant Reed, MD:

Those are the clear-cut cases that we wish everybody was like. However, as we know, not everyone is as clear cut or has ST-segment elevation on ECG. And in those patients that have a VT or VF arrest without ST-segment elevation, it gets to be more nuanced, but we still strongly recommend heart catheterization because up to about a third of patients will have a culprit lesion on catheterization. And then the true nuance comes in, what I would consider, probably at least half, if not most of our patients, and those patients that have a PA arrest without SD segment elevation. And that's what we triage at the ICU and we make a decision about catheterization based on their underlying comorbidities and the likelihood that ischemia is what drove the PEA arrest.

Grant Reed, MD:

We have defined certain unfavorable resuscitation features as we briefly touched on already, but in unwitnessed arrest with a prolonged downtime and a non-VF rhythm are probably the strongest predictors of a poor outcome. That correlates with very low pH, lactic acid, lactate elevation, and then obviously all the comorbidities that come in line with patients who are older and sicker in general. In patients that have at least two of these unfavorable resuscitation features, consideration should be given to CCU triage and then discussion with the team prior to cardiac catheterization. This is the policy that we have in place as an interventional section, and really just stressing this team-based approach to making a decision about taking a patient to the cath lab.

Grant Reed, MD:

In patients that we do take to the cath lab that have coronary artery disease discovered and don't have an obvious ischemic ideology of their arrest, then we encourage discussion with a second interventional colleague, especially prior to placing mechanical circulatory support. We have the great luxury of having a great shock team here, which we also involve in our decision-making in patients that have MCS and needs to stay in after the cath lab. Because these are nuanced decisions and we need the whole team involved, not just in who's taking care of them in the lab, but who will be taking care of them afterward.

Grant Reed, MD:

We have data to support this strategy. We did a meta-analysis here at the Cleveland Clinic, looking at 11 RCTs of patients with out-of-hospital arrests without ST-segment elevation on ECG. We looked at the timing of cardiac catheterization, either an early cardiac cath, meaning less than 24 hours, or a non-early or delayed cardiac catheterization, either having more than 24 hours or not even having a cath at all. And what we found was that there was no difference in mortality or neurologic outcomes. There was also no difference in whether or not patients were likely to receive PCI or their PCI outcomes based on when you stratify the timing of catheterization.

Grant Reed, MD:

Putting it all together, we've come up with this ACE framework, which is assess the patient for their cardiac status, their noncardiac status and their unfavorable resuscitation features. You consult with both us as interventional cardiology, as well as a CCU team and the family to define expectations. Consider the realistic outcomes of what the treatment would be and then plan ahead of whether or not you think mechanical circulatory support would be needed. And in patients with an out-of-hospital arrest without ST-segment elevation on ECG, there isn't as much of a reason to rush. We have time to talk about this and think because these are often the patients that will unfortunately not do as well.

Grant Reed, MD:

In summary, patients with an out-of-hospital arrest and ST-segment elevation on ECG, they should be treated as STEMI. And those are more of the clear-cut cases because they have a presumed ischemic cause. If they have VT or VF, we strongly recommend a heart catheterization. However, there are still noncardiac causes or nonischemic causes for that. Risk stratification is important in all our patients. And this is where Dr. Bajzer will step in and talk about where should the stop sign be prior to the cath lab so that we can deliver the best care, the most efficient care, and ultimately help our patients get the best outcome without subjecting them to unnecessary procedures.

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