Nifedipine Angina Myocardial Infarction Study - NAMIS

Description:

Nifedipine for symptom control and mortality in unstable angina.

Hypothesis:

To estimate the efficacy of nifedipine with "conventional treatment" for unstable angina.

Study Design

Study Design:

Patients Screened: 1,338 (UA); 3,143 (MI)
Patients Enrolled: 126 (UA); 171 (MI)
Mean Follow Up: 6 months
Mean Patient Age: 56% > 60 years (UA); 43% > 60 years (MI)
Female: 40% (UA); 19% (MI)

Patient Populations:

Unstable angina: Chest pain within 24 hours; ECG evidence of reversible ischemia or documented coronary disease
MI: Chest pain > 45 min duration within 6 hours, with ECG evidence of myocardial infarction

Exclusions:

Unstable angina: New infarction or LBBB; Age < 21 or > 80 years; previous CABG; prior participation in NAMIS or concurrent nifedipine therapy; systolic BP < 100 mmHg; MI within 21 days; childbearing potential
MI: LBBB; previous CABG; cardiogenic shock; systolic BP < 110 mmHg; MI within 21 days, childbearing potential

Primary Endpoints:

UA: control of anginal pain and incidence of progression to myocardial infarction
MI: Infarct size index from creatinine kinase MB isoenzyme elevations

Secondary Endpoints:

MI: Mortality at 6 months

Drug/Procedures Used:

UA:Nifedipine or conventional therapy (propranolol and nitrates) x 14 days.
MI: Nifedipine (20 mg q 4 hours) or placebo x 14 days.

Concomitant Medications:

UA: Pre-randomization propranolol (which had been ineffective in controlling symptoms) was continued as background therapy for all patients. MI: Systematic use of beta-blockers and nitrates was avoided.

Principal Findings:

Unstable angina: There were no significant differences between conventionally and nifedipine-treated patients with regard to the time to relief of pain as judged by life table analysis, or the percentage of patients who developed infarction (14% in both groups). In the 14 days after randomization, there were four deaths among those initially randomized to nifedipine and no deaths among those assigned to conventional therapy (p=0.13).

Myocardial infarction: 105 eligible patients with threatened myocardial infarction and 66 with acute myocardial infarction were enrolled. The incidence of progression to infarction among patients with threatened myocardial infarction was not significantly altered by nifedipine (36 of 48 [75%] for placebo-treated and 43 of 57 [75%] for nifedipine-treated patients). Infarct size index was similar among placebo- and nifedipine-treated patients. Among the 171 eligible patients, 6 month mortality did not differ significantly (8.5% for placebo vs 10.1% for nifedipine, NS), but mortality in the 2 weeks after randomization was significantly higher for nifedipine-treated patients (0% for placebo compared with 7.9% for nifedipine, p = .018).

Interpretation:

There was no significant benefit of nifedipine in either unstable angina or myocardial infarction. Nifedipine did not prevent progression to acute myocardial infarction or limit infarct size. Overall, short-acting nifedipine cannot be recommended for patients with acute coronary syndromes.

References:

1. Circulation 1984;69:728-39. Final results (Unstable Angina [UA])
2. Circulation 1985;69:740-7. Final results (myocardial infarction [MI])

Clinical Topics: Acute Coronary Syndromes

Keywords: Life Tables, Myocardial Infarction, Acute Coronary Syndrome, Chest Pain, Nitrates, Propranolol, Electrocardiography, Nifedipine, Calcium Channel Blockers


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