[A cost-effectiveness analysis of prognostic studies in acute uncomplicated myocardial infarct]

The prognostic assessment of the acute myocardial infarction may be obtained through clinical criteria, particularly in patients who are symptomatic during admission, or with several studies in patients without complications. The "effectiveness" of such investigations has been long studied, but not so their "efficiency", which analyses the relationships between costs and outcomes. The goal of the present study is to report the results of a cost-effectiveness analysis of various combinations of diagnostic tests.

One hundred and fifteen patients (age < 65) with uncomplicated first acute myocardial infarction were evaluated. In all patients exercise test, two-dimensional echocardiogram thallium-201 scintigraphy, radionuclide ventriculography, Holter monitoring and cardiac catheterization were performed. The effectiveness was calculated as the "global value" (rate of correctly diagnosed patients: complications prediction during the first year follow-up) of every of such tests combinations. We have used the direct differential costs estimated following the "Colegio Oficial de Médicos de Barcelona" standards. The index used in the cost-effectiveness analysis was the medium cost person/global value. The lowest index corresponded to the most efficient test combination.

The highest effectiveness was found for the exercise test plus bidimensional echocardiography combination (global value = 0.64). At the same time it was the less expensive combination (medium cost = 14.444 ptas); therefore, its index was the lowest (21.724 ptas/patient).

In patients with a first uncomplicated myocardial infarction, the performance of exercise test and echocardiogram is the less costly and most effective combination of studies for one year prognosis. In these patients, routine cardiac catheterization does not improve the results.