PROCAMIO

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PROCAMIO: Randomized Comparison of Intravenous Procainamide Vs. Intravenous Amiodarone for the Acute Treatment of Tolerated Wide QRS Tachycardia

Ortiz. European Heart Journal: Advanced Access June 2016, doi:10.1093/eurheartj/ehw230

Clinical Question

  • In patients with wide QRS (probably ventricular) tachycardia, does intravenous procainamide compared with intravenous amiodarone reduce major adverse cardiac events?

Design

  • Multi-centre, prospective, open labelled randomised control trial
  • Block randomisation in groups of ten on 1:1 basis with allocation concealment maintained through use of sealed envelopes
  • Unblinded
  • Study period was 20mins of drug administration + 20mins following administration + observation period of 24hrs
  • Modified intention to treat analysis
  • Sample size calculation: 302 patients required to detect an absolute risk reduction of 15% from a baseline rate of 20% in the procainamide group

Setting

  • 26 hospitals in Spain, 16 of which recruited
  • Cardiology and Emergency Departments
  • Study recruited over 6yr period (stopped early at this point due to decreasing recruitment rate)
  • Study period not explicitly defined

Population

  • Inclusion criteria:
    • Adults with regular wide complex tachycardia
      • HR≥120bpm, QRS≥120ms
    • Haemodynamically stable: BP ≥90; No dyspnoea at rest, severe angina nor signs of peripheral hypoperfusion
  • Exclusion criteria:
    • Treatment with either study drug in proceeding 24hrs
    • Poor haemodynamic tolerance
    • Irregular tachycardia
    • Tachycardia deemed supraventricular (based mostly on response to vagal manoeuvres or adenosine, ECG analysis not encouraged)
    • Contraindications to study drugs
  • 74 patients randomised
    • 12 patients excluded post randomisation
      • non-sustained VT (n=4), study drug in preceding 24 hours (n=3), protocol violation (n=1), other (n=4)

Intervention

  • Procainamide
    • 10mg/kg over 20mins

Control

  • Amiodarone
    • 5mg/kg over 20mins

Outcome

  • Primary outcome: Incidence of Major Cardiac Adverse Effect (MACE) during study period – significantly reduced in Procainamide vs. Amiodarone group
    • 9% vs. 41%,  Odds Ratio (OR) 0.1, 95% C.I. 0.03-0.6, p=0.006, Fragility index of 3 patients
    • The majority of patients in both group who developed a MACE required immediate Direct Current Cardioversion
    • MACE defined as
      • Clinical signs of hypoperfusion
      • Signs of Heart Failure
      • Severe Hypotension (≤70mmHg SBP if pre-treatment BP ≤100mmHg and ≤80mmHg if pre-treatment BP >100mmHg)
      • Tachycardia acceleration > 20bpm
      • Fast Polymorphic VT
  • Secondary outcomes
    • Termination of VT – significantly increased in Procainamide vs. Amiodarone group
      • 67% vs. 38% (OR 3.3, 95% C.I. 1.2-9.3, p=0.026, Fragility index of 1 patient)
      • For intention to treat analysis (included patients that were excluded post randomisation): 68% vs. 42% (OR 2.7, 95% C.I. 1.04-7.08, p=0.04, Fragility index of 1 patient)
    • Total Adverse Events – No significant difference
      • 24% vs. 48% (OR 0.34, 95% C.I. 0.12-1, p=0.052)
    • Adverse Events during 24hr observation period – No significant difference
      • 18% vs. 31% (OR 0.49 95% C.I. 0.15-1.6, p=0.24)
  • Subgroup Analysis in patients with structural heart disease also showed lower major cardiac adverse events and higher termination rate in the Procainamide group.

Authors’ Conclusions

  • For the treatment of the acute episode of sustained monomorphic well-tolerated wide QRS tachycardia (probably VT), procainamide therapy was associated with less major cardiac adverse events and a higher proportion of tachycardia termination within 40 min.

Strengths

  • Randomised control trial
  • Multi-centre
  • Clinically relevant question and end points studied
  • Trial registered at clinicaltrials.gov

Weaknesses

  • Unblinded
  • Did not reach estimated sample size calculated by power calculation
  • Low fragility index
  • Procainamide is not widely available in UK Emergency Departments
  • No comparison with safety/efficacy of electrical cardioversion
  • Unexpectedly high rate of adverse effects in amiodarone arm.This may have been due to the fact that amiodarone was given over 20 minutes. ALS guidelines recommend it being given over 20-60 minutes for stable VT.

The Bottom Line

  • The results of this trial suggest an improved safety profile and efficacy of 10mg/kg intravenous procainamide over 20mins when compared with 5mg/kg intravenous amiodarone over 20mins in tolerated wide complex tachycardia.

External Links

Metadata

Summary author: Joe Schrieber @j_schrieber
Summary date: 21/07/2016
Peer-review editor: @davidslessor

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