52 in 52 – #24: Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation

Welcome back to the “52 in 52” series. This collection of posts features recently published must-know articles. Post #24 looks at angiography after out-of-hospital cardiac arrest without ST elevation.


Author: Brannon Inman (Chief Resident, Emergency Medicine Physician, San Antonio, TX) // Reviewed by: Alex Koyfman, MD (@EMHighAK); and Brit Long, MD (@long_brit)


Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation

AKA: The “TOMAHAWK” Trial

Question: 

In patients with Out-of-Hospital Cardiac Arrest (OHCA) and no STEMI on EKG, does routine immediate angiography improve 30-day all-cause mortality?

 

Study design: multicenter, open-label, randomized controlled trial

 

PICO

Population:

  • Enrolled
    • Adults ≥ 30 years old
    • All comers with Out-of-Hospital Cardiac Arrest (OHCA)
      • Included those with PEA/ Asystole
      • Included those with VT/VF
      • ROSC achieved
    • Exclusion Criteria
      • ST-segment elevation or LBBB
      • No return of circulation on hospital admission
      • Severe hemodynamic or electrical instability that required immediate angiography or intervention
        • Life-threatening arrhythmia
        • Cardiogenic shock
      • Obvious extra-cardiac cause
        • TBI
        • Metabolic/electrolyte disorder
        • Toxicologic cause
        • Primary respiratory failure
        • Suffocation/ drowning
      • In-hospital cardiac arrest
      • Pregnancy (known or suspected)
      • Participation in another trial interfering with the research questions of TOMAHAWK trail

Intervention:

  • Immediate transfer to angiography lab

 

Comparator:

  • Delayed or selective angiography
    • Patients admitted to ICU
    • angiography delayed a minimum of 24 hours
  • Criteria for angiography earlier than 24 hours:
    • Substantial myocardial damage
      • Troponin ≥ 70 times upper limit of normal ≥ 6 hours post-arrest
      • CK ≥ 10 times upper limit of normal ≥ 6 hours post-arrest
    • Electrical instability
    • Cardiogenic shock
    • Development of new STEMI

 

Outcome:

  • Primary outcome was 30-day all-cause mortality
    • No significant difference (Immediate vs Delayed)
      • 54 vs 46 %
      • HR 1.28 (95% CI, 1.00 – 1.63)
  •  No statistically significant difference in secondary outcomes
    • Myocardial Infarction: 0% vs 0.8%
    • Severe Neurological Deficit: 18.8% vs 12.7%
    • Median ICU LOS: 7 vs 8 days
    • 30d rehospitalization for congestive cardiac failure: 0.4% vs 0.4%
    • Median peak cardiac enzymes:
      • Trop T: 0.39 vs 0.34 μg/L
      • Trop I: 1.46 vs 1.10 μg/L
    • Median peak creatinine: 133 μmol/L vs 133 μmol/L
    • Moderate / Severe bleeding: 4.6% vs. 3.4%
    • Stroke: 1.6% vs. 2.1%
    • AKI leading to RRT: 18.9% vs. 15.8%
  • Explicitly stated the secondary outcomes not adjusted for multiplicity and may not be reproducible (meaning they are hypothesis-generating only)
  • Coronary Angiography
    • Angiography performed: 95.5% vs 62.2%
    • Median time from arrest until angiography: 2.9 vs 46.9 hrs
    • Culprit Lesion: 38.1 vs 43.0%
    • PCI performed: 37.2% vs 43.2%

Take Aways:

  • Negative Trial
  • There does not appear to be a significant benefit in immediate angiography vs delayed. However, angiography was delayed quite a bit (2.9 vs 46.9 hours).
  • Interestingly there appears to be a trend toward mortality in the immediate angiography group, though this was not statistically significant.
  • Overall, the groups were well balanced. There was a slightly higher shockable rhythm rate in the delayed group. Troponin I was slightly higher in the immediate group, and there was history of CABG was more frequent in the delayed group.
  • This was a sick cohort of patients, with an average GCS of 3 in both groups, average lactate of 5 mmol/L in the immediate group, and 4.9 mmol/L in the delayed.
  • There was a high rate of cross-over from the delayed group (46, 17% had angiography in less than 24 hrs).
    • 22 were study violations
    • 24 due to prespecified criteria for early angiography
  • About 4.5% of patients in the immediate group did not have angiography, and only 62.2 % of the delayed group had angiography.
    • The delayed group had a higher percentage of PCI and culprit lesions. I have to wonder if this is because operators were allowed to be selective about which patients went to angiography in this group.

My Take:

  • Based on these data, immediate angiography in otherwise stable OHCA patients who do not have STEMI or LBBB on their post-ROSC EKG does not improve .

References:

  1. Desch S, Freund A, Akin I, et al. Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation. N Engl J Med. 2021;385(27):2544-2553. doi:10.1056/NEJMoa2101909.

 

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