Danish Myocardial Infarction Trial - DANAMI

Description:

Invasive vs. conservative strategy for inducible ischemia in first MI.

Hypothesis:

To compare an invasive strategy of percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) with a conservative strategy in patients with inducible myocardial ischemia who received thrombolytic treatment for a first acute myocardial infarction (AMI).

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 1,008
Mean Follow Up: 2.4 years
Mean Patient Age: 56
Female: 17

Patient Populations:

Patients ≤ 69 years old
Definite AMI (elevation of creatine kinase-MB to at least twice the upper-normal limit, ST deviation or T changes and/or Q waves)
Thrombolytic treatment begun within 12 hours after onset of symptoms.

Exclusions:

Previous AMI, PTCA, or bypass surgery.
Patients receiving less than half of the planned thrombolytic dose.
Patients requiring immediate invasive intervention, including drug-resistant unstable angina pectoris.
Drop in systolic blood pressure during exercise.
Significant noncoronary disease, including significant renal failure or coagulopathy.
Participation in other intervention studies.
Expected incomplete follow-up.
Unable to perform a symptom-limited bicycle exercise test.
ECG abnormalities precluding evaluation of the ST segment during exercise, (including left bundle-branch block or pacemaker).

Primary Endpoints:

Death, reinfarction, or admission with unstable angina

Secondary Endpoints:

Incidence of angina pectoris, severity of angina according to CCS classification, consumption of anti-ischemic medication.

Concomitant Medications:

Aspirin

Principal Findings:

All 1008 patients underwent an exercise test. In each group, the median maximal work capacity was 125 W.

Patients randomized to invasive therapy underwent angiography within 2 weeks of the exercise test. Full revascularization was sought with PTCA or CABG. Patients randomized to the conservative strategy received medical therapy.

Of the 503 patients randomized to an invasive strategy, PTCA was performed in 266 (52.9%) and CABG in 147 (29.2%) from 2 to 10 weeks after the AMI. Of the 505 patients in the conservative treatment group, only 8 (1.6%) had been revascularized 2 months after the AMI.

The patients were followed from 1 to 4.5 years. At 2.4 years follow-up (median), mortality was 3.6% in the invasive treatment group and 4.4% in the conservative treatment group (not significant). Invasive treatment was associated with a lower incidence of AMI (5.6% versus 10.5%; P = .0038) and a lower incidence of admission for unstable angina (17.9% versus 29.5%; P < .00001).

The percentages of patients with a primary end point were 15.4% and 29.5% at 1 year, 23.5% and 36.6% at 2 years, and 31.7% versus 44.0% at 4 years (P = < .00001) in the invasive and conservative treatment groups, respectively.

Interpretation:

Invasive treatment in post-AMI patients with inducible ischemia results in a reduction in the incidence of reinfarction, fewer admissions for unstable angina, and a lower prevalence of stable angina. No significant difference in mortality was seen. We conclude that patients with inducible ischemia before discharge who have received treatment with thrombolytic drugs for their first AMI should be referred to coronary arteriography and revascularized accordingly.

The results of this study parallel those of TIMI 3b, which detected no difference between invasive and conservative strategies following thrombolytic therapy.

References:

1. Circulation 1997;96:748-55. Final results

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Aortic Surgery, Cardiac Surgery and SIHD, Chronic Angina

Keywords: Thrombolytic Therapy, Myocardial Infarction, Follow-Up Studies, Creatine Kinase, Angina, Stable, Fibrinolytic Agents, Coronary Artery Bypass, Angioplasty, Balloon, Coronary, Exercise Test


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