Resolved:

EM physicians should consider administering thrombolytic therapy to cardiac arrest patients

Background:

• Up to 70% of cardiac arrests are due to acute myocardial infarction or acute pulmonary embolism
• Intravenous thrombolytics are widely recommended for STEMI patients where there is a delay to cardiac cath and for PE patients in shock
• Multiple case series and retrospective studies showed improved survial in STEMI/PE patients receiving thrombolysis during cardiac arrest

The "TROICA" study:

• Study design: Prospective, randomized, placebo controlled, double-blind
• Patient population: Witnessed out of hospital cardiac arrest, with ALS response within 10 minutes n =1050
• Intervention: weight based tenecteplase
• Primary outcome: survival at 30 days
• Results: No difference in any outcome measures between intervention and placebo group

"Pro-lytics" arguments:

• The TROICA study relied on paramedic determination of "likely cardiac cause of death," which is difficult to determine even under ideal conditions, likely leading to the inclusion of many patients with non-thrombosis causes of cardiac arrest

• The patient population in the TROICA study, therefore, is difficult to generalize to patients with known or strongly suspected MI or PE as the cause of cardiac arrest in the hospital with immediate CPR

• If thrombolytics are effective and indicated for patients in profound shock from MI or PE, it stands to reason they should be considered if that profound shock progresses to cardiac arrest

"Anti-lytics" arguments:

• The only 2 randomized controlled trials to examine the efficacy of thromblysis in cardiac arrest found no benefit

• Thrombolytics carry an increased risk of hemorrhage as well as a large price tag

• Animal trials suggest that the amount of thrombolytic drug delivered to the coronary arteries in cardiac arrest is near zero, calling into question even theoretical efficacy

And the winner (determined by resident before and after voting) is......

PRO-THROMBOLYSIS (by the very smallest of margins!)

Our (Controversial) Conclusion

• In patients with known or strongly suspected AMI or PE as the cause of cardiac arrest, thrombolysis may be considered in a carefully selected patient cohort likely to benefit

Source:

Wenzel, V., Carli, P. A., Bluhmki, E., Arntz, H.-R., Böttiger, B. W., Adgey, J. A., … Danays, T. (2008). Thrombolysis during Resuscitation for Out-of-Hospital Cardiac Arrest. New England Journal of Medicine, 359(25), 2651–2662. https://doi.org/10.1056/nejmoa070570