Unstable angina: revascularisation led to fewer symptoms.

Clinical bottom line (level 2c)

  1. Rates of angiography, PTCA and CABG varied widely between countries.
  2. Patients in Brazil and the USA were more likely to get angiography (NNT = 3 at 6 months) , PTCA (NNT = 9 at 6 months) , or CABG (NNT = 9 at 6 months) , than patients in Canada, Australia, Hungary and Poland. Most interventions happen within seven days in Brazil and the USA.
  3. Patients in Brazil and the USA were less likely to have refractory angina or be readmitted with unstable angina (NNT = 16 at 6 months) , but were more likely to have a stroke (NNH = 140 at 6 months) , or a major bleed (NNH = 120 at 6 months) .
  4. There was no significant difference in cardiac deaths or subsequent MI in any country.
Yusuf et al: Lancet 1998; 352: 507-514
Expires June 2003

The study

Outcome study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: 95 acute hospitals, Australia, Brazil, Canada, Hungary Poland, USA

7987 patients (aged mean about 65 years, ~60% male) admitted with unstable angina or suspected myocardial infarction starting within 48 hours of admission (either ECG changes or documented coronary artery disease- eg. previous MI, positive exercise test, previous angiogram showing significant heart disease)

Excluded if
  • ST elevation of >=1 mm on >=2 leads
  • previous and recent normal coronary angiogram
  • primary valvular heart disease with significant hemodynamic effects
  • hypertrophic cardiomyopathy
  • unrelated disorder likely to reduce life expectancy


    • angiogram, coronary artery bypasss grafting (CABG), percutaneous transluminal coronary angioplasty (PTCA)

    Multivariate regression was used to adjust for confounding factors.

    ?100% followed for 6 months
    Outcomes studied:
  • angioplasty at seven days
  • PTCA at seven days
  • CABG at seven days
  • cardiac death/MI at seven days
  • refractory angina at seven days
  • stroke at seven days
  • major bleeding at seven days
  • angiography at six months
  • PTCA at six months
  • CABG at six months
  • cardiac death/MI at six months
  • refractory angina or readmission for unstable angina at six months
  • stroke at six months
  • major bleed at six months

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    angioplasty at seven days 6 months / 20.5%
    (% to %)
    PTCA at seven days 6 months / 5.0%
    (% to %)
    CABG at seven days 6 months / 1.6%
    (% to %)
    cardiac death/MI at seven days 6 months / 4.9%
    (% to %)
    refractory angina at seven days 6 months / 5.6%
    (% to %)
    stroke at seven days 6 months / 0.18%
    (% to %)
    major bleeding at seven days 6 months / 0.36%
    (% to %)
    angiography at six months 6 months / 39.2%
    (% to %)
    PTCA at six months 6 months / 12.9%
    (% to %)
    CABG at six months 6 months / 14.6%
    (% to %)
    cardiac death/MI at six months 6 months / 10.8%
    (% to %)
    refractory angina or readmission for unstable angina at six months 6 months / 20.1%
    (% to %)
    stroke at six months 6 months / 1.2%
    (% to %)
    major bleed at six months 6 months / 1.1%
    (% to %)

    prognostic factor for
    angioplasty at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil vs Canada/Australia/Hungary Poland 7 days /
    (20.5%)     		5.6
    (5.0 to 6.2)     		3
    (2 to 3)

    prognostic factor for
    PTCA at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (5.0%)     		3.6
    (3.1 to 4.3)     		9
    (7 to 11)

    prognostic factor for
    CABG at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (1.6%)     		8.0
    (6.3 to 10.2)     		10
    (8 to 13)

    prognostic factor for
    cardiac death/MI at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (4.9%)     		0.91
    (0.7 to 1.1)     		-240
    (-70 to 220)

    prognostic factor for
    refractory angina at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (5.6%)     		0.67
    (0.53 to 0.85)     		-56
    (-130 to -39)

    prognostic factor for
    stroke at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (0.18%)     		2.8
    (1.2 to 6.5)     		310
    (102 to 2800)

    prognostic factor for
    major bleeding at seven days     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 7 days /
    (0.36%)     		2.7
    (1.5 to 4.9)     		170
    (72 to 560)

    prognostic factor for
    angiography at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (39.2%)     		3.5
    (3.2 to 3.9)     		3
    (3 to 4)

    prognostic factor for
    PTCA at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (12.9%)     		2.1
    (1.9 to 2.4)     		9
    (8 to 11)

    prognostic factor for
    CABG at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (14.6%)     		2.0
    (1.7 to 2.2)     		9
    (8 to 13)

    prognostic factor for
    cardiac death/MI at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (10.8%)     		0.97
    (0.8 to 1.1)     		-350
    (-51 to 110)

    prognostic factor for
    refractory angina or readmission for unstable angina at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (20.1%)     		0.64
    (0.56 to 0.73)     		-16
    (-22 to -13)

    prognostic factor for
    stroke at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (1.2%)     		1.6
    (1.1 to 2.4)     		140
    (61 to 840)

    prognostic factor for
    major bleed at six months     		time to outcome control rate (%) unadjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    USA/Brazil 6 months /
    (1.1%)     		1.8
    (1.2 to 2.7)     		120
    (55 to 460)

    • At seven days; six months, angiography:
      • Brazil 60%; 72%
      • USA 58%; 65%
      • Canada 35%; 57%
      • Australia 22%; 41%
      • Hungary 15%; 32%
      • Poland 2%; 16%
    • Seven days; six months, PTCA;
      • Brazil 12%; 22%
      • USA 22%; 26%
      • Canada 9%; 22%
      • Australia 5%; 13%
      • Hungary 4%; 8%
      • Poland 0%; 4%
    • Seven days; six months, CABG:
      • Brazil 10%; 27%
      • USA 14%; 22%
      • Canada 2%; 18%
      • Australia 1%; 16%
      • Hungary 3%; 17%
      • Poland 0.2%; 6%
    • Seven days; six months, cardiac death/MI:
      • Brazil 22%; 11.5%
      • USA 3.8%; 8.8%
      • Canada 5.3% 11.9%
      • Australia 3.7%; 9.3%
      • Hungary 5.6%; 11.9%
      • Poland 5.6% 10.8%
    • Seven days; six months, refractory angina:
      • Brazil 4.8% 8.9%
      • USA 5.0%; 11%
      • Canada 2.4%; 15.1%
      • Australia 5.8%; 18.5%
      • Hungary 9.7% 12.7%
      • Poland 6.6% 9.7%
    • Seven days; six months, stroke:
      • Brazil 0.3%; 1.6%
      • USA 0.8%; 2.0%
      • Canada 0.1%; 1.1%
      • Australia 0.2%; 1.2%
      • Hungary 0.2%; 1.3%
      • Poland 0.2%; 0.7%
    • Seven days, six months, major bleeding:
      • Brazil 0.6%; 1.3%
      • USA 1.5%; 2.6%
      • Canada 0.4%; 1.3%
      • Australia 0.3%; 1.0%
      • Hungary 0.4%; 0.6%
      • Poland 0.4%; 1.1%

    Comments

    1. No clinical significant difference between adjusted and unadjusted odds ratios.
    2. No data given on costs. This study support systematic reviews that show revascularisation reduces symptoms, but does not prolong life. Policy for each country has to be based on economic factors.

    Citation

    1. Yusuf S, Flather M, Pogue J, et al: variations between countries in invasive cardiac procedures and outcomes in patients with suspected unstable angina or myocardial infarction without initial ST elevation. Lancet 1998; 352: 507-514
    Search Terms: hand search
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer: William Rhoton

    Clinical Question.
    Patient unstable angina or suspected MI
    Intervention or Exposure prevalence of treatments
    Outcome various countries