MPS 16-02 Implication of Night-time Mean Systolic Blood Pressure for Predicting Subclinical Target Organ Damage in Hypertension

Abstract

Objective: We aimed to compare central pressures with 24hr ambulatory blood pressure monitoring (ABPM) for prediction of subclinical target organ damage in HTN, assessed by urine albumin creatinine ratio (UACR) and subclinical left ventricular (LV) mechanical dysfunction reflected by global LV longitudinal strain (LV GLS). Design and Method: Tota1 of 122 HTN (57 male, age 53 ± 15) with preserved LV ejection fraction (EF > 50%) underwent 24hr ABPM. Diary times were used to calculate night-time mean SBP (mSBP). 2D speckle-tracking echocardiography was done to assess LV GLS. Office base peripheral SBP, central SBP using radial artery tonometry, and UACR was measured. Results: In simple correlation analysis, night-time mSBP showed significant correlations with central and peripheral SBP (r = 0.81, p < 0.01; r = 0.52, p < 0.01). Log UACR and LV GLS were significantly associated with night-time mSBP (r = 0.32, p < 0.01; r = 0.28 p < 0.01) but not with central or peripheral SBP. From multivariate analysis, night-time mSBP was significantly associated with UACR (P = 0.03) and LV GLS (P = 0 .01) independently of central or peripheral SBP. Diagnostic performance of night-time mSBP for UACR ≥ 15 mg/g was significantly better (p < 0.01) than that of central SBP (Figure). Conclusions: Night- time mSBP better correlated with mechanical function of LV and UACR than central SBP. Night-time mSBP may be important therapeutic target in HTN, as it better reflect sustained chronic mechanical loads to LV than one-time measured central pressure.