Background: The administration of verapamil during the reperfusion phase of acute myocardial infarction can reduce the extent and severity of microvessel damage and limit myocardial dysfunction. We aimed at investigating the effect of early verapamil administration on left ventricular remodeling and the clinical evolution after myocardial infarction.
Methods: Eighty-eight patients with first acute anterior myocardial infarction thrombolysed < 4 hours from symptom onset were enrolled in a multicenter, randomized, double-blind, controlled study of verapamil administration (5 mg i.v. + 2 microg/kg/min over 24 hours). Echocardiographic end-diastolic (EDV) and end-systolic (ESV) left ventricular volumes were assessed by biplane Simpson's rule.
Results: At 90 days, EDV in the verapamil and placebo groups was respectively 88.9 +/- 27.8 and 95.8 +/- 30.7 ml (p = 0.11), ESV was 52.6 +/- 22.7 and 57.7 +/- 25.4 ml (p = 0.18). There was no change over time in the verapamil group (day 3 vs day 90: EDV 85.0 +/- 17.7 vs 88.9 +/- 27.8 ml, p = NS; ESV 48.7 +/- 14.1 vs 52.6 +/- 22.7 ml, p = NS) while left ventricular volume increased in the placebo group (day 3 vs day 90: EDV 87.6 +/- 21.1 vs 95.8 +/- 30.7 ml, p = 0.03; ESV 52.0 +/- 16.9 vs 57.7 +/- 25.4 ml, p = 0.08). NYHA functional classes were differently distributed at 30 and 90 days (chi2 = 0.009 and 0.07), with a lower prevalence of classes II and III in the verapamil group (p = 0.03).
Conclusions: The early intravenous administration of verapamil in thrombolysed patients can reduce left ventricular remodeling and NYHA functional class after acute anterior myocardial infarction.