New AHA Statement on Cardiac Cath Lab Activation After OHCA

Written by Laura Murphy

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The goal of invasive management in the cardiac catheterization laboratory (CCL) is to identify and treat culprit coronary lesion or additional resuscitative measures (such as mechanical circulatory support (MCS) or interventions for massive pulmonary embolism). This is a scientific statement from the American Heart Association (AHA) which provides an update on the role of CCL in the management of resuscitated patients or those with ongoing cardiac arrest.

Activate or not?
Coronary artery disease may account for up to 70% of sudden cardiac arrest cases, though the proportion of ischemic cause of OHCA is decreasing. Assessment of patients resuscitated from OHCA should focus on identifying likelihood of acute ischemic trigger to guide decision about urgent invasive angiography. Post-ROSC ECG is an important component of this¹. Benefits of invasive therapies should be balanced with potential consequences of anoxic encephalopathy, particularly for patients with one or more of the following risk factors for poor neurologic outcome².

So Who Benefits from the Cath Lab?

• OHCA with STE on ECG: >80% of these patients have acute coronary occlusion. There are no RCTs directly studying the role of emergent cardiac catheterization in patients with OHCA and STE; there is little question about benefit of emergency reperfusion in this population. Outcomes in comatose patients are overall much worse than awake patients, likely due to death from anoxic brain injury or multiorgan failure. Benefit is questionable for patients with signs suggesting poor neurological outcome, but more information is needed to determine patients in whom coronary reperfusion is not beneficial or harmful. As such, coronary reperfusion continues to have a critical role in this subset of patients, and guidelines provide a Class 1 Recommendation for emergency angiography and reperfusion.
• OHCA without STE on ECG: Up to 1/3 of these patients may have an acute coronary occlusion, but recent studies have collectively failed to demonstrate a benefit to emergency angiography compared to delayed or no angiography. However, in patients with high degree of suspicion for coronary occlusion (e.g. history of chest pain, marked ST depressions, posterior MI), or who have cardiogenic shock or electrical instability, early invasive strategy may still be beneficial. For these patients, the guidelines provide a Class 2a recommendation for proceeding with emergency angiography.
• Cardiac arrest with cardiogenic shock (CS): Data in this group of patients with OHCA are lacking, and rates of anoxic encephalopathy and irreversible end-organ injury are higher. Patients with more favorable prognostic features may benefit from coronary reperfusion as well as initiation of mechanical circulatory support (MCS) such as intra-aortic balloon pump (IABP), Impella or TandemHeart, or VA-ECMO.
• Cardiac arrest with massive PE: While fibrinolytic therapy remains the standard of care for patients with massive PE with OHCA, catheter-directed lysis or mechanical thrombectomy, with or without VA-ECMO in the CCL, can be considered in patients with contraindications to fibrinolytics or with treatment failure. As such, AHA provides a Class 2a Recommendation for proceeding with treatment of confirmed PE and OHCA in the CCL.
• Cardiac Arrest with Ongoing CPR: Increased use of mechanical compression devices may have benefit in the CCL setting; while AHA assigns Class 3 Recommendation to routine use of these devices, they assign a Class 2b Recommendation for use in situations such as CCL where it is otherwise challenging to provide high quality CPR.
• ECPR: Several trials which have demonstrated survival benefit compared to conventional CPR, leading to a Class 2a Recommendation for ECPR for select patients with cardiac arrest if cause of arrest is deemed to be potentially reversible. However, successful implementation of ECPR requires experienced as well as highly resourced and integrated systems. While there is promising data from regional systems, but it is challenging to replicate these systems nationwide.

In general, best practices focus on minimizing potential for procedure-related complications include radial access (unless plan for MCS), PCI of culprit lesions only, minimization of IV contrast use, and use of IV P2Y12 agents if concern for poor oral absorption to avoid in-stent thrombosis.

How will this change my practice?
This statement highlights the importance of post-ROSC ECG as well as other clinical factors to determine who may benefit from activation of CCL for diagnostic, therapeutic and resuscitative support after OHCA. In patients without STE on post-ROSC ECG, I will be discussing patients with high clinical suspicion of ischemic event or with cardiogenic shock or electrical instability with cardiology for consideration of emergent catheterization. The same goes for patients with OHCA secondary to massive pulmonary embolism.

Source
Cardiac Catheterization Laboratory Management of the Comatose Adult Patient With an Out-of-Hospital Cardiac Arrest: A Scientific Statement From the American Heart Association. Circulation. 2024 Jan 30;149(5):e274-e295. doi: 10.1161/CIR.0000000000001199. Epub 2023 Dec 19. PMID: 38112086.

¹Post-ROSC ECG with ST elevation has 85% positive predictive value and 65% negative predictive value for acute coronary artery lesion, but global myocardial ischemia is insensitive and nonspecific due to poor perfusion as well as metabolic abnormalities which may be present, so serial ECGs may be helpful.

²These include advanced age, unwitnessed arrest, absence of bystander CPR, nonshockable rhythm on initial assessment, prolonged duration or cardiac arrest, elevated lactic acid (>7), low pH (<7.2), or diffuse cerebral edema on CT. Presence of >6 unfavorable features predicts poor survival. There are also a variety of clinical risk scores (described in Table 1 or the article) which have been used to estimate risk of poor outcomes after OHCA.