Myocardial infarction: post-infarction ischaemia:: invasive therapy decreased reinfarction and unstable angina pectoris.

Clinical bottom line (level 1b)

  1. Patients with acute myocardial infarction and post-infarction ischaemia who were given invasive therapy were less likely to have unstable angina pectoris, than those given conservative therapy (NNT = 9 at 12 months) .
  2. Patients given invasive therapy were less likely to have a reinfarction (NNT = 20 at 12 months) .
  3. There was no clear difference in mortality at 12 months.
Madsen et al: Circulation 1997; 96: 748-755
Expires March 2003

The study

Unblinded ?concealed randomised trial with intention-to-treat
Setting: 43 hospitals, Denmark

1008 patients (aged range 24 to 69 years; mean 56, 83% male) Definite acute myocardial infarction and thrombolytic therapy begun within 12 hours of the onset of symptoms, with inducible postinfarction ischaemia (either symptomatic angina pectoris presenting spontaneously >36 hours after admission or during predischarge exercise test or ST changes during exercise, compatible with ischaemia).

Excluded if
  • previous myocardial infarction, percutaneous transluminal coronary angioplasty or bypass surgery
  • receiving less than half of the planned thrombolytic dose
  • requiring immediate invasive intervention, including drug-resistant unstable angina pectoris
  • drop in systolic blood pressure during exercise
  • significant noncoronary disease


    • Note:
  • All patients underwent an exercise test.


    • Control Group: (n = 505, 505 analysed): Conservative therapy- medical treatment, including the choice of anti-ischaemic medication, prescribed according to local practice.
    Experimental Group: (n = 503, 503 analysed): Invasive therapy- percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. All patients underwent coronary arteriography.
    Patients in the conservative arm who developed severe angina pectoris were referred to coronary arteriography at the discretion of the referring physician.
    100% followed for 12 months Mean follow-up was 2.4 years (range 1 to 4 years).
    Outcome notes:
    • unstable angina pectoris : Number of patients with one or more admissions.

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    unstable angina pectoris 12 months 149
    (39.0%)    		 90
    (17.9%)    		 39.0%
    (24.0% to 52.0%)    		 11.6%
    (6.41% to 16.8%)    		 9
    (6 to 16)
    reinfarction 12 months 53
    (10.5%)    		 28
    (5.57%)    		 47.0%
    (18.0% to 66.0%)    		 4.93%
    (1.59% to 8.27%)    		 20
    (12 to 63)
    mortality 12 months 22
    (4.36%)    		 18
    (3.58%)    		 18.0%
    (-51.1% to 55.0%)    		 0.78%
    (-1.63% to 3.19%)    		 129
    (NNT = 31 to infinity;
    NNH = 61 to infinity)

    Comments

    1. The recruitment of patients was not consecutive in all departments, and a log of all acute myocardial infarction admissions was not kept.
    2. There were two complications in the invasive therapy group.

    Citation

    1. Madsen JK, Grande P, Saunamaki K, et al: Danish multicenter randomized study of invasive versus conservative treatment in patients with inducible ischemia after thrombolysis in acute myocardial infarction (DANAMI). Circulation 1997; 96: 748-755
    Contributor: Chris Ball and Clare Wotton, January 2000
    Reviewer:

    Clinical Question.
    Patient acute myocardial infarction
    Intervention or Exposure conservative treatment
    Comparison invasive treatment
    Outcome death