Coronary heart disease: a simplified predictive index helped predict complications.

Clinical bottom line (level 1a)

  1. Less than a twentieth of patients undergoing their first coronary angioplasty had major complications (infarction, emergency bypass surgery or death).
  2. 1% of patients considered low risk with a predictive index had major complications.
  3. About 2% of patients considered at moderate risk had major complications.
  4. A twentieth of patients considered high risk had major complications.
  5. A sixth of patients considered very high risk had major complications.
Kimmel et al: Journal of the American College of Cardiology 1995; 26 (4): 931-938
Expires March 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: 42 centres, USA

5250 patients (aged mean 62 years, ?% male) first coronary angioplasty
Coronary angioplasty.

Multivariate logistic regression was used to adjust for confounding factors.

100% followed for 12 months
Outcomes studied:
  • major complications (myocardial infarction, emergency bypass surgery or death)
  • major complications with no risk factors (low risk)
  • major complications with 1-2 factors (moderate risk)
  • major complications with 3 factors (high risk)
  • major complications with more than 3 factors (very high risk)

    • Only patients with multivessel disease were included in the predictive index as this has been identified as an independent predictor of complications.
    • For the predictive index, each prognostic factor that was present yielded a score of one. The seven variables used were aortic valve disease, left main coronary angioplasty, shock, acute myocardial infarction within 24 hours of coronary angioplasty, type C lesion coronary angioplasty, multivessel disease and unstable angina. Risk classes were classified as: low- no risk factors present; moderate- one or two risk factors; high- three risk factors; very high- more than three factors.

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    major complications 12 months 202/5250 3.85%
    (3.33% to 4.37%)
    major complications with no risk factors (low risk) 12 months 27/2054 1.31%
    (0.82% to 1.81%)
    major complications with 1-2 factors (moderate risk) 12 months 74/2970 2.49%
    (1.93% to 3.05%)
    major complications with 3 factors (high risk) 12 months 10/184 5.43%
    (2.16% to 8.71%)
    major complications with more than 3 factors (very high risk) 12 months 7/42 16.7%
    (5.40% to 27.9%)

    Comments

    1. There were 10,030 patients in the validation set and 5,250 had multivessel disease. There were 10,622 patients in the validation set, of which 4,289 had multivessel disease.
    2. The importance of lesion characteristics as predictors of myocardial infarction has been reported to be blunted in the current era of easily placed stents and GP IIb-IIIa antagonists

    Citation

    1. Kimmel SE, Berlin JA, Strom BL, et al: Development and validation of a simplified predictive index for major complications in contemporary percutaneous transluminal coronary angioplasty practice. Journal of the American College of Cardiology 1995; 26 (4): 931-938
    Contributor: Clare Wotton and Bob Phillips, January 2000
    Reviewer: Neal S Kleiman

    Clinical Question.
    Patient percutaneous transluminal coronary angioplasty
    Intervention or Exposure predictive index score
    Outcome major complications