REBEL Cast Episode 27: The PROCAMIO Trial – IV Procainamide vs IV Amiodarone for the Acute Treatment of Stable Wide Complex Tachycardia

Background: In the ACLS guidelines stable Ventricular Tachycardia (VT) can be treated with either IV amiodarone or IV procainamide, as the drugs of choice. This has been given a class II recommendation, but there has not been a controlled prospective trial to base the use of one drug over the other in the clinical setting. Despite both medications having a class II recommendation, both clinically and anecdotally it appears that amiodarone is the preferred agent in clinical practice.

REBEL Cast Episode 27: The PROCAMIO Trial -IV Procainamide vs IV Amiodarone for the Acute Treatment of Stable Wide Complex Tachycardia

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What Article are we Reviewing?

1. Ortiz M et al. Randomized Comparison of Intravenous Procainamide vs. Intravenous Amiodarone for the Acute Treatment of Tolerated Wide QRS Tachycardia: the PROCAMIO Study. Eur Heart J 2016. PMID: 27354046

What They Did:

• Multicenter, randomized, prospective, open-label study
• IV procainamide vs IV amiodarone for well-tolerated ventricular tachycardia
  • IV procainamide 10mg/kg over 20 min
  • IV amiodarone 5mg/kg over 20 min

Outcomes:

• Primary: Major Cardiac Adverse Events within 40 min after infusion initiation
  • Clinical signs of peripheral hypoperfusion
  • Heart failure signs: dyspnea at rest and/or orthopnea associated with signs of pulmonary congestion
  • Severe hypotension: SBP ≤ 70mmHg if the pre-treatment SBP was ≤ 100mmHg or SBP ≤ 80mmHg if the pre-treatment SBP was >100mmHg
  • Tachycardia acceleration of >20 bpm of its mean value
  • Appearance of fast polymorphic VT
• Secondary:
  • Acute termination of tachycardia
  • Total adverse events during 24h observation period

Results:

Strengths:

• This is the first multicenter, prospective, randomized controlled trial comparing IV procainamide vs IV amiodarone

Limitations:

• Sample size calculation had significant uncertainties due to a dearth of prior studies (1 randomized trail of IV procainamide & small observational studies of IV amiodarone). Study would have needed >300 patients to detect a 15% difference in major adverse events.
• Slow recruitment – after 6 years at 26 participating centers only 74 patients were recruited
• The sample size of this study was much smaller than what was needed based on sample size calculations

Discussion:

• ALWAYS place defibrillator pads on your patient before giving IV procainamide or amiodarone as the most common major cardiac event in both groups was severe hypotension requiring immediate electrical cardioversion, however no deaths occurred in this study.
• 74 patients recruited, but 6 in each arm (12 total) were excluded due to protocol violations or development of exclusion criteria before drug treatment
• Before the PROCAMIO trial, the only trial comparing procainamide vs amiodarone is a retrospective multicenter cohort trial of 90 patients [2]
• It is possible that a dose lower than 5mg/kg IV of amiodarone could have resulted in less adverse effects, but could potentially also lower the efficacy of the medication.
• Know when to stop infusions. For procainamide, the QRS duration must be monitored and an increase by > 50% necessitates drug cessation

Author Conclusion: “This study compares for the first time in a randomized design intravenous procainamide and amiodarone for the treatment of the acute episode of sustained monomorphic well-tolerated (probably) ventricular tachycardia. Procainamide therapy as associated with less major cardiac adverse events and a higher proportion of tachycardia termination within 40 min.”

Clinical Take Home Point: Although this is a small clinical study, it is a well done randomized controlled trial that shows procainamide is associated with less major cardiac adverse events, more efficacious in terminating tachycardia, and more importantly more efficacious in both endpoints in a subgroup of patients with structural heart disease. Procainamide should be first line chemical therapy in patients with stable ventricular tachycardia.

Infographic Created By: Mark Ramzy, DO (Twitter: @MRamzyDO)

References:

1. Ortiz M et al. Randomized Comparison of Intravenous Procainamide vs. Intravenous Amiodarone for the Acute Treatment of Tolerated Wide QRS Tachycardia: the PROCAMIO Study. Eur Heart J 2016. PMID: 27354046
2. Marill KA et al. Amiodarone or Procainamide for the Termination of Sustained Stable Ventricular Tachycardia: An Historical Multicenter Comparison. Acad Emerg Med 2010; 17: 297 – 306. PMID: 20370763

For More Thoughts on This Topic Checkout:

• Joe Schrieber at The Bottom Line: PROCAMIO – Randomized Comparison of Intravenous Procainamide vs. Intravenous Amiodarone for the Acute Treatment of Tolerated Wide QRS Tachycardia
• Rory Spiegel at EMCrit: The Case of the Dysrhythmic Heart

Post/Podcast Peer Reviewed By: Anand Swaminathan (Twitter: @EMSwami)