SAFETY OF ESMOLOL IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION TREATED WITH THROMBOLYTIC THERAPY WHO HAD RELATIVE CONTRAINDICATIONS TO BETA-BLOCKER THERAPY

OBJECTIVE: This study was conducted to evaluate the safety of esmolol in 114 patients treated with thrombolytic therapy for acute myocardial infarction who also had relative contraindications to beta-blockade, and the predictive value of patient tolerance to esmolol and subsequent patient tolerance of oral beta-blocker therapy. PATIENTS: One hundred and fourteen patients with myocardial infarction documented by enzyme concentrations and electrocardiographic changes who also had relative contraindications to beta-blockade. METHODS: Esmolol was initiated during acute myocardial infarction for myocardial ischemia (n=88), hypertension (n=13), or supraventricular tachycardia (n=13). Relative contraindications to beta-blocker therapy included either active signs/symptoms of left ventricular dysfunction or a history of congestive heart failure (n=40), a history of chronic obstructive pulmonary disease or asthma (n=31), bradycardia (HR <60 beats/min; n=18), peripheral vascular disease (n=15), or hypotension (systolic BP <100 mm Hg; n=14). RESULTS: During initial esmolol dose titration, 69 patients tolerated 300 mug/kg/min, 12 patients tolerated 200 mug/kg/min, 17 patients tolerated 100 mug/kg/min, and 16 patients tolerated 50 mug/kg/min. Twenty-eight patients (25 percent) developed dose-limiting adverse effects during esmolol maintenance infusions. Sixteen patients required esmolol dose reduction and 12 required esmolol discontinuation. Adverse effects reversed within 30-45 minutes following dose reduction or discontinuation. The 86 patients who tolerated esmolol infusions without dose reduction or drug discontinuation were subsequently treated with oral beta-blockers. Eleven of these patients (13 percent) developed adverse effects requiring oral beta-blocker discontinuation. Nine of these patients had tolerated only 50 mug/kg/min of esmolol, and the other 2 patients had tolerated only 100 mug/kg/min. CONCLUSIONS: Esmolol can be used safely in most patients treated with thrombolytic therapy for acute myocardial infarction who have relative contraindications to beta-blockers. Tolerance to higher maintenance doses of esmolol is a good predictor of subsequent outcome with oral beta-blocker therapy.