Angina: CABG decreases angina and reintervention more than PTCA.

Clinical bottom line (level 1a)

  1. Coronary artery bypass surgery reduces angina (NNT = 7 at 12 months) , and the need for revascularisation (NNT = 3 at 12 months) . These benefits are after three years.
  2. The effect on death or myocardial infarction is unclear, but any potential benefit is not large.
Pocock et al: Lancet 1995; 346: 1184-1189
Expires July 2003

The study

Systematic review of randomised controlled trials of
  • Patients: angina
  • Intervention: coronary artery bypass grafting (CABG) compared with percutaneous transluminal coronary angioplasty (PTCA)
  • Outcome: death or MI


    • Articles found in ?languages using unspecified databases, (search terms: not stated ) and studies were identified through shared communication at large annual cardiology meetings and by contacting experts.

    Selection criteria: not detailed
    Appraisal criteria: not detailed
    Articles excluded if: unclear

    eight randomised controlled trials of 3371 patients with single and multivessel disease, followed for 1 to 8 years (mean ~3 years). 1710 had PTCA, 1661 CABG. No details on age or sex.
    There was significant heterogeneity noted between studies.

    The evidence

    Outcome Time to outcome CER RR
    (95% CI)    		 NNT
    (95% CI)
    death 12 months 79/
    (4.60%)    		 1.08
    (0.79 to 1.50)     		270
    (NNT = 43 to infinity;
    NNH = 100 to infinity)
    death or MI 12 months 135/
    (7.90%)    		 1.03
    (0.84 to 1.27)     		420
    (NNT = 47 to infinity;
    NNH = 79 to infinity)
    angina 12 months 278/1582
    (17.6%)    		 1.56
    (1.30 to 1.88)     		10
    (7 to 19)
    revascularisation 12 months 577/
    (33.7%)    		 0.10
    (0.075 to 0.13)     		3
    (3 to 3)
    angina 3 years 148/934
    (15.9%)    		 1.23
    (0.99 to 1.54)     		29
    (NNT = 12 to infinity;
    NNH = 630 to infinity)

    • Separate analyses for single-vessel and multi-vessel disease showed that the rates of mortality, and subsequent angina were slightly lower in single-vessel disease at one year.

    Comments

    1. PTCA technique has undergone major improvements since trial completion, in particular, the introduction of intracoronary stents.
    2. The review is made weaker by the unclear search techniques, data analysis and the heterogeneity between the trials.
    3. Decisions need to be made on the basis of the patients age, disease state and preferences for the interventions.

    Citation

    1. Pocock SJ, Henderson RA, Rickards AF, et al: Meta-analysis of randomised trials comparing coronary angioplasty with bypass surgery. Lancet 1995; 346: 1184-1189
    Search Terms: unstable angina in Best Evidence
    Contributor: Chris Ball and Clare Wotton, July 2000
    Reviewer: Thomas Mathew

    Clinical Question.
    Patient angina
    Intervention or Exposure PTCA
    Comparison CABG
    Outcome death, MI