Effects of Renin-Angiotensin System Inhibition on Left Atrial Function of Hypertensive Patients: An Echocardiographic Tissue Deformation Imaging Study

Abstract

Although renin-angiotensin system (RAS) inhibitors have beneficial effects on left ventricular myocardium, their effect on left atrial (LA) function remains unknown. The aim of this study was to evaluate the effect of treatment with RAS inhibitors on LA function of patients with essential hypertension. Forty hypertensive patients (17 males, mean age 47.1 +/- 1.5, mean blood pressure 158.3 +/- 1.8/97.1 +/- 0.7 mm Hg) were studied using LA strain and strain rate (SR) imaging before and after 9 months of treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs). Standard echocardiographic parameters of LA function (LA volumes, ejection fraction, active and passive emptying fraction, and ejection force), as well as left ventricular diastolic indexes did not change with RAS-blocking treatment. However, peak systolic LA strain and SR were significantly higher at study end compared to baseline (77.8 +/- 5.2% vs. 63.3 +/- 4.1%, P < 0.001 and 3.9 +/- 0.2 s(-1) vs. 3.1 +/- 0.2 s(-1), P < 0.0001, respectively). No correlation was found between changes in systolic or diastolic blood pressure, and changes in strain or SR change during treatment. LA strain and SR imaging improved after reduction of blood pressure with RAS inhibitors in hypertensive patients, whereas standard LA echocardiographic parameters remained unchanged. LA strain/SR values may have a role in detecting subclinical myocardial involvement in essential hypertension at an early stage; the association between change in these indexes after antihypertensive treatment and clinical outcome merits further evaluation.