The effect of verapamil on left ventricular remodelling and diastolic function after acute myocardial infarction (The Verapamil Infarction Study on Remodelling and Relaxation-VISOR)

The VISOR is a double blind, randomized, placebo-controlled study aimed to assess the effects of early and prolonged administration of verapamil on th e left ventricular geometry and diastolic function in patients with anterio r acute myocardial infarction treated with thrombolysis. Patients with hear t failure or ejection fraction < 45% were excluded. Within 12 hours from st arting thrombolysis, 70 patients were given verapamil (5 mg/hour intravenou sly for the first 24 hours, followed by 120 mg t.i.d. perorally for 6 month s) or equivalent placebo. Echocardiograms were performed on admittance, bef ore discharge, after 3 months and 6 months. The following parameters were c alculated: left ventricular volumes, ejection fraction, sphericity index, e arly (E) and late (A) transmitral peak flow velocities and time-velocity in tegrals with their ratios, deceleration time and half-time of E, isovolumic relaxation time (IVRT), and non-invasive time constant of ventricular rela xation (tau). The basal and the last available parameters were considered f or statistical analysis. The effects of the treatment on the left ventricul ar volumes, ejection fraction, and sphericity index were not statistically relevant. Conversely, a reduction of E/A ratio (P < .05) and increases of A integral (P < .01), deceleration time and half-time E, IVRT and tau (P < . 05) were found in the placebo group and not in the verapamil group. No sign ificant changes in the blood pressure, heart rate, PQ interval, and biochem ical parameters were observed in the two groups. In conclusion, in patients with a thrombolysed anterior acute myocardial infarction and preserved sys tolic function, verapamil can prevent alterations of the diastolic function in absence of effect on ventricular remodelling, and has a good safety pro file.