Ting-Yan Xu

Beat-to-Beat, Reading-to-Reading, and Day-to-Day Blood Pressure Variability in Relation to Organ Damage in Untreated Chinese

Whether target organ damage is associated with blood pressure (BP) variability independent of level remains debated. We assessed these associations from 10-minute beat-to-beat, 24-hour ambulatory, and 7-day home BP recordings in 256 untreated subjects referred to a hypertension clinic. BP variability indices were variability independent of the mean, maximum–minimum difference, and average real variability. Effect sizes (standardized &bgr;) were computed using multivariable regression models. In beat-to-beat recordings, left ventricular mass index (n=128) was not (P≥0.18) associated with systolic BP but increased with all 3 systolic variability indices (+2.97–3.53 g/m2; P<0.04); the urinary albumin-to-creatinine ratio increased (P⩽0.03) with systolic BP (+1.14–1.17 mg/mmol) and maximum–minimum difference (+1.18 mg/mmol); and pulse wave velocity increased with systolic BP (+0.69 m/s; P<0.001). In 24-hour recordings, all 3 indices of organ damage increased (P<0.03) with systolic BP, whereas the associations with BP variability were nonsignificant (P≥0.15) except for increases in pulse wave velocity (P<0.05) with variability independent of the mean (+0.16 m/s) and maximum–minimum difference (+0.17 m/s). In home recordings, the urinary albumin-to-creatinine ratio (+1.27–1.30 mg/mmol) and pulse wave velocity (+0.36–0.40 m/s) increased (P<0.05) with systolic BP, whereas all associations of target organ damage with the variability indices were nonsignificant (P≥0.07). In conclusion, while accounting for BP level, associations of target organ damage with BP variability were readily detectable in beat-to-beat recordings, least noticeable in home recordings, with 24-hour ambulatory monitoring being informative only for pulse wave velocity.

Blood flow pattern in the middle cerebral artery in relation to indices of arterial stiffness in the systemic circulation.

BACKGROUND The brain is perfused at high-volume flow throughout systole and diastole. We explored the association of blood flow in the middle cerebral artery (MCA) with the pulsatile components of blood pressure in the systemic circulation and indices of arterial stiffness. METHODS We enrolled 334 untreated subjects (mean age, 50.9 years; 45.4% women) who had been referred for ambulatory blood pressure monitoring to Ruijin Hospital, Shanghai, China. We measured the MCA pulsatility index (PI) by transcranial Doppler ultrasonography. The indices of arterial stiffness included pulse pressure (brachial (bPP) and central (cPP) measured at the office and 24-h ambulatory (24-h PP)) and carotid-femoral (cf-PWV) and brachial-ankle (ba-PWV) pulse wave velocity. Effect sizes, expressed per 1 s.d., were adjusted for sex, age, heart rate, and mean pressure. RESULTS Women had faster MCA blood flow than men (68.0 vs. 58.3 cm/s), but lower PI (75.4 vs. 82.3%; P < 0.001). The five arterial stiffness indices were intercorrelated (r ≥ 0.37; P < 0.001). PI increased (P ≤ 0.045) with bPP (+6.78%), cPP (+5.56%), 24-h PP (+7.58%), cf-PWV (+1.59%), and ba-PWV (+3.46%). In explaining PI variance, bPP ranked first (partial r(2) = 0.25), 24-h PP second (0.20) and cPP third (0.14). In models including both cf-PWV and ba-PWV, only the latter was significant (-0.19%; P = 0.84 vs. +3.54%; P < 0.001). In models including both bPP and ba-PWV, only the former contributed to PI variance (+6.98%; P < 0.001 vs. -0.24%; P = 0.78). CONCLUSION MCA blood flow is closely associated with the pulsatile pressure in the systemic circulation, which depends on arterial stiffness as measured by PWV.

Strategies for Classifying Patients Based on Office, Home, and Ambulatory Blood Pressure Measurement

Hypertension guidelines propose home or ambulatory blood pressure monitoring as indispensable after office measurement. However, whether preference should be given to home or ambulatory monitoring remains undetermined. In 831 untreated outpatients (mean age, 50.6 years; 49.8% women), we measured office (3 visits), home (7 days), and 24-h ambulatory blood pressures. We applied hypertension guidelines for cross-classification of patients into normotension or white-coat, masked, or sustained hypertension. Based on office and home blood pressures, the prevalence of white-coat, masked, and sustained hypertension was 61 (10.3%), 166 (20.0%), and 162 (19.5%), respectively. Using daytime (from 8 AM to 6 PM) instead of home blood pressure confirmed the cross-classification in 575 patients (69.2%), downgraded risk from masked hypertension to normotension (n=24) or from sustained to white-coat hypertension (n=9) in 33 (4.0%), but upgraded risk from normotension to masked hypertension (n=179) or from white-coat to sustained hypertension (n=44) in 223 (26.8%). Analyses based on 24-h ambulatory blood pressure were confirmatory. In adjusted analyses, both the urinary albumin-to-creatinine ratio (+20.6%; confidence interval, 4.4–39.3) and aortic pulse wave velocity (+0.30 m/s; confidence interval, 0.09–0.51) were higher in patients who moved up to a higher risk category. Both indexes of target organ damage and central augmentation index were positively associated (P⩽0.048) with the odds of being reclassified. In conclusion, for reliably diagnosing hypertension and starting treatment, office measurement should be followed by ambulatory blood pressure monitoring. Using home instead of ambulatory monitoring misses the high-risk diagnoses of masked or sustained hypertension in over 25% of patients.

Three-dimensional speckle strain echocardiography is more accurate and efficient than 2D strain in the evaluation of left ventricular function

BACKGROUND Two-dimensional speckle tracking echocardiography (2DSTE) has been used widely in research, but rarely in clinical practice because data acquisition and analysis are time-consuming. By reducing the acquisition and analysis time, 3-dimensional STE may improve clinical impact. We investigated the feasibility of 3DSTE myocardial deformation, with comparison to 2DSTE. METHODS Transthoracic 3DSTE and 2DSTE were performed in 230 adults (138 men, 51 ± 14 years, and 142 hypertension, 10 heart failure and 78 normotensive subjects). The variables of LV deformation were analyzed using EchoPAC software. RESULTS The 3D LV longitudinal (LS) analysis was feasible in 84.9% of the study subjects, which was lower than the 2D analysis (97.2%). The success rates for circumferential strain (CS) and radial strain (RS) were similar between the 2D and 3D techniques. All magnitude of strains measured by 2DSTE and 3DSTE were significantly correlated. The magnitude of 3D LS and CS was lower, but the 3D RS is higher than that of 2DSTE (-18.5 ± 2.8 vs. -21.2 ± 3.5; 20.8 ± 4.1 vs. 21.7; and 50.0 ± 11.2 vs. 37.7 ± 12.6, respectively). Strains measured by 3DSTE exhibited stronger correlation with LV ejection fraction (EF) than that by 2DSTE. In inter- and intra-observer reproducibility for 3D LS, CS, RS and AS were acceptable. The mean time of analysis for LV volume, EF and strains was 116s by 3DSTE, which was significantly shorter than that by 2DSTE (5 min, P<0.0001). CONCLUSIONS Three-dimensional STE is feasible and reproducible in the estimation of LV function, requires substantially less time than 2DSTE and is a more feasible technique for LV function assessment in clinical practice.

Association of Target Organ Damage With 24-Hour Systolic and Diastolic Blood Pressure Levels and Hypertension Subtypes in Untreated Chinese

The association of target organ damage with 24-hour systolic and diastolic blood pressure levels and ambulatory hypertension subtypes has not yet been examined in untreated Chinese patients. We measured left ventricular mass index by echocardiography (n=619), the urinary albumin:creatinine ratio (n=1047), and aortic pulse wave velocity by tonometry (n=1013) in 1047 untreated subjects (mean age, 50.6 years; 48.9% women). Normotension was a 24-hour systolic/diastolic blood pressure <130/<80 mm Hg. Hypertension subtypes were isolated diastolic hypertension and mixed systolic plus diastolic hypertension. We assessed associations of interest by multivariable-adjusted linear models. Using normotension as reference, mixed hypertension was associated with higher (P⩽0.003) left ventricular mass index (+4.31 g/m2), urinary albumin:creatinine ratio (+1.63 mg/mmol), and pulse wave velocity (+0.76 m/s); and isolated diastolic hypertension was associated with similar left ventricular mass index and pulse wave velocity (P≥0.39), but higher urinary albumin:creatinine ratio (+1.24 mg/mmol; P=0.002). In younger participants (<55 years), the mutually independent effect sizes associated with 1 SD increases in 24-hour systolic/diastolic blood pressure were +3.31/–0.36 g/m2 (P=0.009/0.79) for left ventricular mass index, +1.15/+1.14 mg/mmol (P=0.02/0.04) for the urinary albumin:creatinine ratio, and +0.54/–0.05 m/s (P<0.001/0.54) for pulse wave velocity. In older participants, these estimates were +3.58/+0.30 g/m2 (P=0.045/0.88), +1.23/+1.05 mg/mmol (P=0.002/0.54), and +0.76/–0.49 m/s (P<0.001/<0.001), respectively. In conclusion, 24-hour systolic blood pressure and mixed hypertension are major determinants of target organ damage irrespective of age and target organ, whereas 24-hour diastolic blood pressure and isolated diastolic hypertension only relate to the urinary albumin:creatinine ratio below middle age.

Left atrial function as assessed by speckle-tracking echocardiography in hypertension.

AbstractWe investigated left atrial (LA) function in relation to hypertension using 2-dimensional speckle-tracking echocardiography (STE) in subjects with preserved left ventricular (LV) ejection fraction, while accounting for LA enlargement and LV mass and diastolic function.We performed standard 2-dimensional and Doppler echocardiography and LA volumetric measurements and STE strain imaging in hypertensive patients (systolic/diastolic blood pressure ≥140/90 mmHg, or use of antihypertensive drugs, n = 124) and age- and sex-matched normotensive subjects (n = 124). We measured the peak LA velocity, strain, and strain rate during systole and early and late diastole, respectively. We investigated the associations of interests in the presence or absence of LA enlargement (LA volume index ≥28 mL/m2).Hypertensive and normotensive subjects had similar LV ejection fraction and LA diameter (P ≥ 0.22). However, hypertensive compared with normotensive subjects had enlarged LV and impaired diastolic function, and had increased LA volumetric measurements and decreased LA emptying fractions (P < 0.0001). Hypertensive patients also had impaired LA function, as measured by STE velocity, strain, and strain rate in general and in the absence of LA enlargement (P < 0.0001). The differences in LA STE strain rate during LV systole and LA contraction between hypertension and normotension in the absence of LA enlargement remained statistically significant (P < 0.001), after adjustment for age, sex, and LV mass index and E/E’.Hypertension is associated with impaired LA function, as assessed by STE strain imaging technique, even before LA enlargement develops and after LV remodeling is accounted for.

Ambulatory (AASI), but not home (HASI), arterial stiffness index is associated with aortic pulse wave velocity

Ambulatory (AASI), but not home (HASI), arterial stiffness index is associated with aortic pulse wave velocity

Association of Stroke with Ambulatory Arterial Stiffness Index (AASI) in Hypertensive Patients

The ambulatory arterial stiffness index (AASI) predicted stroke in hypertensive patients and in the general populations. However, no similar data was available in Chinese. In the present study, we sought confirmation that Chinese hypertensive patients with a history of stroke would have an elevated AASI. We retrospectively analyzed the data of 156 hypertensive outpatients (60.9 % men; mean age, 61.5 years) and 582 inpatients (63.6 % men; 58.6 years) of the Hypertension Department at Ruijin Hospital in Shanghai, China. The AASI was calculated as 1 − the regression slope of diastolic blood pressure (DBP) on systolic blood pressure (SBP) in individual 24-h ambulatory recordings. With adjustment applied for sex, age, body mass index (BMI), the 24-h mean arterial pressure, and other cardiovascular risk factors, AASI was higher in patients with a history of stroke than in patients without stroke in both outpatient (0.51 ± 0.02 vs. 0.47 ± 0.01; P = 0.050) and inpatient (0.46 ± 0.01 vs. 0.44 ± 0.01; P = 0.031) cohorts. The odds ratio (OR) for a history of stroke associated with a 1-SD increase in AASI was 1.63 (95% confidence interval (CI), 1.01–2.62; P = 0.046) in outpatients, 1.32 (1.01–1.74; P = 0.046) in inpatients, and 1.30 (1.05–1.62; P = 0.018) in two patient cohorts combined (n = 738) after multivariate adjustment including the night-to-day ratio of SBP. Our findings suggest that Chinese hypertensive patients with a history of stroke, compared to those without such history, have stiffer arteries, as exemplified by a higher AASI.

Early diastolic dyssynchrony in relation to left ventricular remodeling and function in hypertension

BACKGROUND Cardiac synchronization is important in maintaining myocardial performance, but the mechanism of diastolic dyssynchrony leading to failing myocardium is unclear. We aim to study the relation of left ventricular (LV) diastolic dyssynchrony with diastolic dysfunction in patients with hypertension. METHODS Two-D, three-D and Doppler echocardiography were performed using the GE Vivid E9 system on 230 subjects. Among them, 154 patients with hypertension were divided into group 1 (86 patients with mild to moderate hypertension, BP 152 ± 8/91 ± 11 mm Hg) and group 2 (68 patients with severe hypertension, BP 188 ± 12/105 ± 24 mm Hg), age 76, gender matched normotensive subjects (119 ± 6/76 ± 9 mm Hg) as control. The routine 2D and Doppler parameters were measured and LV systolic and diastolic dyssynchrony indices were determined as the standard deviation of the time interval from the peak R of the QRS complex to peak myocardial systolic strain rate (Ts-SD), and to early diastolic strain rate (Te-SD) of 12 LV segments. RESULTS LV relative wall thickness, mass index, and Te-SD were significantly higher in patients with hypertension than in control group (p<0.0001), but Ts-SD showed no significant differences. Te-SD and diastolic dysfunction worsened progressively with increasing severity of hypertension (p<0.05). Te-SD was significantly and independently associated with parameters of LV remodeling and diastolic function. CONCLUSION Our study demonstrated that LV diastolic dyssynchrony was associated with LV remodeling, which seems to contribute to diastolic dysfunction in hypertension. This diastolic dyssynchrony index derived from speckle tracking echocardiography can be used as a marker for studying the LV function and effects of therapy in hypertensive heart disease.

The association of serum inflammatory biomarkers with chronic kidney disease in hypertensive patients.

Abstract A positive association between inflammation and chronic kidney disease (CKD) has been reported but the impact of hypertension on this relation remains unclear. The aim of this study is to investigate the association of various inflammation markers with risk of CKD in hypertensive patients. 387 hypertensive patients (mean age 55.5 years) were recruited. Serum matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1(TIMP-1), high-sensitivity C-reactive protein (hsCRP) and osteopontin (OPN) were measured by ELISA. CKD was diagnosed either as evidence of kidney damage, including microalbuminuria, or by low glomerular filtration rate (GFR) (<60 mL/min/1.73 m2), which was estimated using the Modification of Diet in Renal Disease (MDRD) abbreviated equation. Compared with the reference groups (eGFR ≥ 60 mL/min/1.73 m2), the serum levels of TIMP-1, OPN, hsCRP were significantly higher, and the MMP-9/TIMP-1 ratio was lower in the risk group (eGFR < 60 mL/min/1.73 m2). Multiple logistic regression analysis showed that TIMP-1, MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with low GFR separately after adjustment, whereas MMP-9/TIMP-1 ratio, OPN and hsCRP were associated with microalbuminuria. The significant association of MMP-9/TIMP-1 ratio and OPN with low GFR and microalbuminuria persisted after additional adjustment for other studied inflammatory biomarkers. Our data suggest that inflammation is strongly and independently associated with renal damage in hypertensive patients. MMP-9/TIMP-1 ratio and OPN may serve as novel risk factors and therapeutic targets for the treatment of CKD in hypertensive patients.