Is the Cath Lab the Place to be after V fib VTac Cardiac Arrest?
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Ventricular dysrhythmias are commonly caused by coronary ischemia which is most frequently caused by acute coronary artery occlusions in the setting of coronary artery disease. It would seem somewhat logical that patients who suffer a V fib or V Tach cardiac arrest would benefit from a trip to the cardiac catheterization lab to identify and treat these possible acute coronary artery occlusions. Patient’s with EKGs showing ST-elevations following ROSC already go to the Cath lab. Since the EKG is not terrifically sensitive for MI, should V fib V Tach cardiac arrest patients without ST-elevations make a trip to the Cath lab? In this breakdown of our most recent journal club we look at several papers covering this topic. In the podcast below we also talk with Justin Benoit, MD the site PI for the ongoing ACCESS trial which is also looking into this question.
Khan MS, Shah SMM, Mubashir A, et al. Early coronary angiography in patients resuscitated from out of hospital cardiac arrest without ST-segment elevation: A systematic review and meta-analysis. Resuscitation 2017;121:127–34.
Why we chose the article
Not uncommon and vexing problem that we’ve encountered multiple times (especially as third year residents in our program)
Recent studies published and more on the way
This paper represents a historical perspective/jumping off point for the newer RCTs
Why it’s important
The question of what to do with pts w/OHCA and no STEMI after ROSC is difficult, particularly in resource limited setting, and well-researched guidelines are sorely needed
Details of the study
Design - Meta-analysis of published studies looking at the impact of early vs delayed or no CAG following OHCA w/o STEMI
Structured search of literature databases (Medline, Embase, Ovid) by two independent investigators
Primary outcome = short and long term mortality (discharge and 6-14 months)
Secondary outcome = good neurological outcome at discharge and follow up
8 studies (1 RCT and 7 observational) made inclusion
Results
Early CAG = decreased short term and long term mortality (OR 0.46 and 0.59)
Early CAG = improved neurologic outcomes and discharge and follow up (OR 2 and 1.48)
Conclusions
Authors conclude that the results of this meta-analysis support early CAG in OHCA presenting without STEMI on post-ROSC ECG
My analysis
Up to the point of publication of this paper there hadn’t yet been many great studies on this question
The meta-analysis itself is largely based on observational data and many of the individual papers had confidence intervals crossing the null value. The only RCT included was small, and it was a pilot study not powered to detect benefits in mortality or neurological outcomes.
The data isn’t flawed, it just isn’t robust.
The paper does add to the growing body of literature and supports the undertaking of future RCTs, two of which that Mike and Dave will be discussing.
Lemkes JS, Janssens GN, van der Hoeven NW, et al. Coronary Angiography after Cardiac Arrest without ST-Segment Elevation. N Engl J Med 2019;380(15):1397–407.
This was a prospective, randomized, open label, multicenter trial in the Netherlands comparing immediate cardiac angiography to delayed angiography in non-STEMI post ROSC patients. Patients included in this study had an out of hospital cardiac arrest with an initial shockable and were unconscious after ROSC. Patients were excluded if they had a STEMI on EKG or were in shock (defined as a systolic blood pressure less than 90 for greater than 30 minutes).
The authors’ primary endpoint was survival at 90 days, with secondary endpoints of 90 day survival with good neurologic outcome, acute kidney injury, need for renal replacement therapy, time to target temperature, duration of vasopressors and inotropes, duration of mechanical ventilation, and recurrence of ventricular tachycardia requiring defibrillation or cardioversion.
538 patients were enrolled and randomized to either the immediate angiography group or delayed angiography group. They did allow for crossover from delayed angiography to urgent angiography if the patient showed signs of cardiogenic shock, recurrent arrhythmias, or recurrent ischemia. No patients were lost to follow up. 273 patients were randomized into the immediate group while 265 were randomized into the delayed group. 14 percent of patients who were randomized into the delayed group underwent urgent angiography before their planned procedure.
64.5 percent of patients in the immediate angiography group survived at 90 days compared to 67.2 percent in the delayed angiography group, and this difference was not statistically significant. There was no statistically significant difference in any of the secondary outcomes.
This is the first prospective study attempting to answer an important clinical question and showed that immediate cardiac angiography does not improve survival in patients with no STEMI on their EKG after ROSC. There are two main limitations in this study. The first is that patients who were in shock were excluded. The second is the overall generalizability of the patient population studied. While the patient population in this study had similar rates of coronary artery disease to the US population (about 65 percent), only 5 percent of patients were found to have acute thrombotic occlusions. This is significantly less than previous observational studies. It’s also important to remember that 14 percent of patients in the delayed group needed to be taken for angiography early. It is still important to involve interventional cardiology early in the care of these patients and continue to reassess for signs of cardiogenic shock using our physical exam and ultrasonography skills. The main takeaway from this study that I will be applying to my practice is that while cardiac angiography is an important part of post ROSC care, if the patient does not have a STEMI or signs of cardiogenic shock, their angiogram can likely be delayed and they can be safely admitted to the ICU for continued resuscitation.
Elfwén L, Lagedal R, Nordberg P, et al. Direct or subacute coronary angiography in out-of-hospital cardiac arrest (DISCO)—An initial pilot-study of a randomized clinical trial. Resuscitation 2019;139:253–61.
The Direct or Subacute Coronary Angiography in Out-of-hospital Cardiac Arrest (DISCO) trial is a large Swedish randomized control trial that will recruit a total of 1000 patients by time of completion. Patients who have suffered a witnessed out of hospital cardiac arrest and have no STEMI on post-ROSC ECG will be randomized to immediate cardiac catheterization versus delayed cardiac catheterization (no sooner than 3 days post arrest). This is the pilot study designed to examine feasibility of protocol and safety aspects (specifically bleeding, renal failure, PCI findings, secondary transportations and 24 hour mortality).
A total of 79 patients were randomized. Median time from EMS Arrival to coronary angiography was 135 minutes in the immediate catheterization group. No differences were found in bleeding or renal failure. Mortality at 24 hours was 7% in the immediate catheterization group vs 15% in standard care. A culprit lesion was found in 36% of patients in the immediate angiography group. 15% of the patients randomized to standard of care had catheterization performed before the stipulated 3 days primarily due to elevated cardiac enzymes, cardiogenic shock, and focal wall motion abnormality on Echocardiography.
While this pilot study was not designed to look for outcomes of interest to the average EM physician it did seem to answer the feasibility questions as designed (though time to catheterization was longer than the 120 minutes initially specified in the study design). Furthermore there appeared to be a slight trend towards improved mortality in the immediate catheterization group though statistical analysis was not performed. While this study is not practice changing as currently designed it will certainly be interesting to see what it ultimately demonstrates when the full study has finished recruitment.
References
Khan MS, Shah SMM, Mubashir A, et al. Early coronary angiography in patients resuscitated from out of hospital cardiac arrest without ST-segment elevation: A systematic review and meta-analysis. Resuscitation 2017;121:127–34.
Lemkes JS, Janssens GN, van der Hoeven NW, et al. Coronary Angiography after Cardiac Arrest without ST-Segment Elevation. N Engl J Med 2019;380(15):1397–407.
Elfwén L, Lagedal R, Nordberg P, et al. Direct or subacute coronary angiography in out-of-hospital cardiac arrest (DISCO)—An initial pilot-study of a randomized clinical trial. Resuscitation 2019;139:253–61.
Authorship and Conflicts of Interest
Khan et al - Jared Ham, MD, no conflicts of interest
Lemkes, et al - Michael Klaszky, MD, no conflicts of interest
Elfwén, et al - David Habib, MD, no conflicts of interest
Editing and Posting - Jeffery Hill, MD MEd, no conflicts of interest
Guest on Podcast - Justin Benoit, MD, site PI for ongoing ACCESS trial
