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 subsequen t patient tolerance of oral beta-blocker therapy. PATIENTS: One hundre d and fourteen patients with myocardial infarction documented by enzym e concentrations and electrocardiographic changes who also had relativ e contraindications to beta-blockade. METHODS: Esmolol was initiated d uring acute myocardial infarction for myocardial ischemia (n=88), hype rtension (n=13), or supraventricular tachycardia (n=13). Relative cont raindications to beta-blocker therapy included either active signs/sym ptoms 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 vascu lar disease (n=15), or hypotension (systolic BP <100 mm Hg; n=14). RES ULTS: During initial esmolol dose titration, 69 patients tolerated 300 mug/kg/min, 12 patients tolerated 200 mug/kg/min, 17 patients tolerat ed 100 mug/kg/min, and 16 patients tolerated 50 mug/kg/min. Twenty-eig ht patients (25 percent) developed dose-limiting adverse effects durin g esmolol maintenance infusions. Sixteen patients required esmolol dos e reduction and 12 required esmolol discontinuation. Adverse effects r eversed within 30-45 minutes following dose reduction or discontinuati on. The 86 patients who tolerated esmolol infusions without dose reduc tion or drug discontinuation were subsequently treated with oral beta- blockers. Eleven of these patients (13 percent) developed adverse effe cts requiring oral beta-blocker discontinuation. Nine of these patient s had tolerated only 50 mug/kg/min of esmolol, and the other 2 patient s had tolerated only 100 mug/kg/min. CONCLUSIONS: Esmolol can be used safely in most patients treated with thrombolytic therapy for acute my ocardial infarction who have relative contraindications to beta-blocke rs. Tolerance to higher maintenance doses of esmolol is a good predict or of subsequent outcome with oral beta-blocker therapy.