Influence of angiotensin II receptors blocking on overall left ventricle's performance of patients with acute myocardial infarction of limited extent. Echocardiographic assessment

Abstract

Introduction: Recent studies documented the beneficial effect of angiotensin-receptor blockers (ARBs) on patients (pts) with acute myocardial infarction (AMI) combined with left ventricle (LV) systolic dysfunction. The present study intended to assess the impact of the ARB irbesartan, on the overall LV performance in pts with uncomplicated AMI of limited extent.

Methods: Forty consecutive pts with first inferior AMI (AMI-I) and preserved LV-systolic function were enrolled. They were allocated into two groups: (a) 20 pts received the conventional treatment of AMI-I and placebo (CT) and (b) 20 pts administered irbesartan additionally to the conventional treatment (IR). Twenty four healthy individuals of matching age and sex were recruited as control group (CG). Complete echocardiographic examination, Tei index of overall LV function and systolic blood pressure (SBP) were measured on the 8th post-infarct day.

Results: The Tei index of IR group (0.53+/-0.03) was significantly lower compared to that of CT group (0.78+/-0.05) (p<0.001) and was similar to that of CG (0.45+/-0.03)(p=NS). Irbesartan induced a considerable decrease in both isovolumic relaxation (115+/-7 ms vs 140+/-7 ms; p<0.01) and contraction time (52+/-2 ms vs 64+/-3 ms; p<0.01) and a significant increase in ejection time (279+/-6 ms vs 256+/-8 ms; p<0.05). SBP in pts of IR group was similar to that of CT group (112+/-3 mmHg vs 113+/-4 mmHg; p=NS).

Conclusions: Therapy with Irbesartan improves overall LV function of pts with AMI-I. Irbesartan leads to acceleration of the LV relaxation, which possibly indirectly ameliorates LV systolic performance too. This beneficial influence is possible attributed to a direct tissue effect of the drug and not to its hemodynamic action.