Objectives: To analyse the clinical practice concerning the pharmacological therapy of acute myocardial infarction (AMI), comparing it with the guidelines for the management of AMI and exploring the reasons for its under use or over use.
Methods: Retrospective analysis of clinical records of patients with the discharge diagnosis of AMI.
Location: A central hospital in the North of Portugal.
Subjects: One hundred and ninety-one patients admitted to the Internal Medicine Department of a central hospital in the North of Portugal between January 1, 1993, and December 31, 1994.
Results: Thrombolytic therapy was performed in 24.1% of the patients. At discharge 32.6% of the patients were on therapy with beta blockers, 68% with angiotensin converting enzyme inhibitors (ACEI) and 88.4% with aspirin. Stepwise logistic regression produced the following odds ratios for the variables significantly associated with: a) thrombolytic therapy: hypertension - 0.38; non-Q wave infarction - 0.17; time between onset of symptoms and hospital admission greater than 6 hours - 0.18; admission to coronary unit - 14.72; b) beta blocker therapy: age > 60 years - 0.23; serum LDH > 1000 U/L - 0.41; diastolic blood pressure > 85 mmHg - 3.73; Killip > 1 - 0.08; concomitant therapy with calcium antagonist - 0.33; previous therapy with beta blocker - 14.87; hospital stay greater than 10 days - 2.67; c) ACEI therapy: anterior wall infarction - 3.07; non Q wave infarction - 0.13; congestive heart failure - 9.36; serum creatinine > or = 15 mg/dl - 0.03.
Conclusions: Beta blockers and thrombolytic are under used and ACEI overused. The delay in hospital admission is the most important factor opposing the use of thrombolytic therapy, imposing the need for measures that ean reduce this delay. Therapy with beta blockers (highly cost-effective) can be increased by educational intervention among the physicians. The overuse of ACEI can be ascribed to the good results of randomised trials.