The interplay between renin-angiotensin system activation, abnormal myocardial deformation and neurohumoral activation in hypertensive heart disease: a speckle tracking echocardiography study

Angiotensin converting enzyme (ACE) promotes cardiac fibrosis. LV myocardial deformation and torsion are markers of subclinical myocardial dysfunction. We investigated the association of serum ACE levels with LV deformation markers in untreated hypertensives. In 120 untreated patients (age: 53.5 +/- 11.2 years) with essential hypertension and 60 healthy controls, we measured (a) LV longitudinal, circumferential and radial strain (S), peak torsion and the percentage changes between peak twisting and untwisting at the end of early diastolic filling (%dpTw-Utw(EDF)) using speckle tracking echocardiography and (b) serum levels of ACE and NTproBNP. Compared to controls, patients had decreased longitudinal strain (-19.1 +/- 2.9 vs. -21.7 +/- 1.8%), increased peak twisting (19.1 +/- 4.6 vs.14.0 +/- 3.7 deg) but decreased %dpTw-Utw(EDF) (78 +/- 8 vs. 86 +/- 8%) and higher serum ACE levels (27.6 +/- 8.0 vs 20.9 +/- 7.1 U/ml) (p < 0.05 for all comparisons). Increasing serum ACE levels were related to impaired radial strain and longitudinal systolic SR (b = -0.41 and b = 0.31 respectively, p < 0.01), as well as to reduced %dpTw-Utw(EDF) (b = -0.37, p < 0.05). Furthermore, increasing serum ACE levels were related to increasing NTproBNP levels (b = 0.41, p < 0.01). In multivariate analysis, the above relations of serum ACE levels and LV function parameters remained significant after adjustment for other confounding factors (p < 0.01). The close link between serum ACE levels and impaired LV deformation suggests that activation of renin-angiotensin system is involved in the impairment of LV function resulting in elevated LV filling pressures causing the concomitant elevation of BNP levels in untreated hypertensive patients.