P1270Effects of blood pressure variability on layer-specific longitudinal strain in hypertension

Abstract

Background: Our previous study showed sub-epicardial longitudinal strain (EpiLS) was an independent prognostic factor for worse outcome in regular treated hypertension but not global longitudinal strain (GLS) and sub-endocardial longitudinal strain (EndLS). Increased blood pressure variability (BPV) has been found associated with target organ damage in hypertension. However, effects of BPV on layer-specific longitudinal strain have not been well studied.

Purpose: The aim of this study was to investigate the effects of different blood pressure parameters on layer-specific longitudinal strain in hypertension.

Methods: This study included 95 patients (57 men, age 65 ± 12 years) with uncomplicated hypertension who have been regularly treated for more than 1 year. Speckle tracking echocardiography was used for measurement of longitudinal deformation from 3 apical views of left ventricle. GLS was measured by automated function imaging (AFI). We further divided into sub-endocardial and sub-epicardial myocardium and measured their longitudinal strain by manual click-and-draw method and averaged from 3 apical views. Blood pressure parameters included office systolic blood pressure (SBP), office diastolic blood pressure (DBP), central SBP and DBP by tonometry, average 24-hour SBP and DBP, and BPV parameters by ambulatory blood pressure monitor. BPV parameters included standard deviation of daytime SBP (DSSD), standard deviation of nighttime SBP (NSSD), standard deviation of daytime DBP (DDSD), and standard deviation of nighttime DBP (NDSD).

Results: We divided subjects into low and high group according to median level of each strain. No blood pressure parameters were different between low and high EndLS group except week difference in NDSD (9.0 ± 3.4 vs. 7.8 ± 2.0 mmHg, p = 0.051). NSSD (11.2 ± 4.6 vs. 9.3 ± 2.9 mmHg, p = 0.027) and NDSD (9.1 ± 3.4 vs. 7.7 ± 2.0 mmHg, p = 0.031) were significant increased in low GLS group but not other parameters. DDSD (10.3 ± 3.0 vs. 9.0 ± 2.5 mmHg, p = 0.034), NSSD (11.4 ± 4.4 vs. 9.1 ± 3.1 mmHg, p = 0.006), and NDSD (9.2 ± 3.2 vs. 7.6 ± 2.2 mmHg, p = 0.012) were significantly increased in low EpiLS group.

Conclusions: Only BPV parameters were associated with decreased longitudinal strain in hypertension. Effects of BPV were majorly noted in EpiLS.