Ho-Ming Su

Brachial-Ankle Pulse Wave Velocity and Rate of Renal Function Decline and Mortality in Chronic Kidney Disease

BACKGROUND AND OBJECTIVES Increased arterial stiffness was reported to be associated with decreased estimated GFR (eGFR). Previous studies suggested that arterial stiffness might play a role in renal function progression in patients with chronic kidney disease (CKD). The aim of this study was to investigate whether there was an independent association between brachial-ankle pulse wave velocity (baPWV), a marker of arterial stiffness, and renal function progression in CKD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This longitudinal study enrolled 145 patients with CKD stages 3 to 5. The baPWV was measured by using an ABI-form device. The change in renal function was estimated by eGFR slope. The study endpoints were defined as commencement of dialysis or death. RESULTS After a stepwise multivariate analysis, the eGFR slope was positively associated with baseline eGFR and negatively associated with hypertension and baPWV (β=-0.165, P=0.033). Seventeen patients entering dialysis, and eight deaths were recorded. Multivariate forward Cox regression analysis identified that higher baPWV (hazard ratio, 1.001; P=0.001), lower baseline eGFR, and higher serum phosphate level were independently associated with progression to commencement of dialysis or death. CONCLUSIONS Our results show an independent association between baPWV and renal function decline and progression to commencement of dialysis or death in patients with CKD. Screening CKD patients by means of baPWV may help identify a high-risk group of rapid renal function decline and progression to commencing dialysis or death.

Echocardiographic parameters are independently associated with rate of renal function decline and progression to dialysis in patients with chronic kidney disease.

BACKGROUND AND OBJECTIVES Cardiac abnormalities were frequently noted in patients with chronic kidney disease (CKD). This study is designed to assess whether echocardiographic parameters are associated with rate of renal function decline and progression to dialysis in CKD stage 3 to 5 patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This longitudinal study enrolled 415 patients. The renal end point was defined as commencement of dialysis. The change in renal function was measured by estimated GFR (eGFR) slope. RESULTS Progression to dialysis was predicted by wide pulse pressure, low albumin, low hemoglobin, high calcium-phosphorous product, proteinuria, diuretics use, and concentric left ventricular hypertrophy (LVH) (hazard ratio, 2.03; 95% confidence interval [CI], 1.00 to 4.10; P = 0.05). The eGFR slope was negatively associated with total cholesterol, uric acid, proteinuria, diuretics use, and left atrial (LA) diameter (change in slope, -0.50; 95% CI, -0.89 to -0.11; P = 0.01) and positively associated with albumin and left ventricular ejection fraction (LVEF) (change in slope, 0.06; 95% CI, 0.03 to 0.08; P < 0.001). CONCLUSIONS Our study in patients of CKD stage 3 to 5 demonstrated that concentric LVH was associated with progression to dialysis, and that increased LA diameter and decreased LVEF were associated with faster renal function decline. Echocardiography may help identify high-risk groups with progressive decline in renal function to dialysis and rapid progression of renal dysfunction in CKD stage 3 to 5 patients.

Association of Interarm Systolic Blood Pressure Difference with Atherosclerosis and Left Ventricular Hypertrophy

An interarm systolic blood pressure (SBP) difference of 10 mmHg or more have been associated with peripheral artery disease and adverse cardiovascular outcomes. We investigated whether an association exists between this difference and ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and echocardiographic parameters. A total of 1120 patients were included in the study. The bilateral arm blood pressures were measured simultaneously by an ABI-form device. The values of ABI and baPWV were also obtained from the same device. Clinical data, ABI<0.9, baPWV, echocariographic parameters, and an interarm SBP difference ≥10 mmHg were compared and analyzed. We performed two multivariate forward analyses for determining the factors associated with an interarm SBP difference ≥10 mmHg [model 1: significant variables in univariate analysis except left ventricular mass index (LVMI); model 2: significant variables in univariate analysis except ABI<0.9 and baPWV]. The ABI<0.9 and high baPWV in model 1 and high LVMI in model 2 were independently associated with an interarm SBP difference ≥10 mmHg. Female, hypertension, and high body mass index were also associated with an interarm SBP difference ≥10 mmHg. Our study demonstrated that ABI<0.9, high baPWV, and high LVMI were independently associated with an interarm SBP difference of 10 mmHg or more. Detection of an interarm SBP difference may provide a simple method of detecting patients at increased risk of atherosclerosis and left ventricular hypertrophy.

Ankle brachial index as a predictor for mortality in patients with chronic kidney disease and undergoing haemodialysis.

Aim:  The ankle brachial index (ABI) is a marker for peripheral artery disease and can predict mortality in advanced chronic kidney disease (CKD) and haemodialysis patients, respectively. However, it is seldom studied in Taiwan, an area with high prevalence of CKD and end‐stage renal disease. The aim of this study was to investigate the predictors for mortality by using ABI value in patients with CKD and undergoing haemodialysis in Taiwan.

Global left ventricular longitudinal systolic strain as a major predictor of cardiovascular events in patients with atrial fibrillation

Objective Although global left ventricular longitudinal systolic strain (GLS) is a sensitive measure of left ventricular mechanics, its relationship with adverse cardiovascular (CV) events in atrial fibrillation (AF) has not been evaluated. This study sought to examine the ability of GLS in predicting CV events in AF. Design Observational cohort study. Setting Department of cardiology in a university hospital. Patients 196 persistent AF patients referred for echocardiographic examination. Main outcome measures The risk of GLS measured by index beat method for CV events was assessed by Cox proportional hazards analyses. CV events were defined as CV death, non-fatal stroke and hospitalisation for heart failure. Results There were 19 CV deaths, 12 non-fatal stroke and 28 hospitalisations for heart failure during an average follow-up of 21±10 months. Multivariate analysis showed worsening GLS (HR 1.121; 95% CI 1.023 to 1.228, p=0.014) was independently associated with increased CV events. In direct comparison, GLS outperformed left ventricular ejection fraction (LVEF) and systolic mitral annulus velocity (Sa) in predicting adverse CV events both in univariate and multivariate models (p≤0.043). Besides, the addition of GLS to a Cox model containing chronic heart failure, hypertension, age ≥75 years, diabetes, prior stroke score, estimated glomerular filtration rate, LVEF and Sa provided an additional benefit in the prediction of adverse CV events (p=0.022). Conclusions GLS was a major parameter and stronger than LVEF and Sa in predicting adverse CV events and could offer an additional prognostic benefit over conventional clinical and echocardiographic systolic parameters in AF.

Significant Correlation between Ankle-Brachial Index and Vascular Access Failure in Hemodialysis Patients

BACKGROUND AND OBJECTIVES Vascular access failure (VAF) is associated with increased morbidity and mortality in hemodialysis patients. The most common cause of VAF is stenosis at the arteriovenous anastomosis because of abnormal neointimal proliferation and extracellular matrix deposition. These two changes are also observed in the classic atheroma, which means atherosclerotic lesions and venous stenosis in VAF may share some similar pathogenic mechanisms. The ankle-brachial index (ABI) is a reliable marker for atherosclerosis. The aim of this study was to evaluate the relationship between ABI <0.9 and VAF. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS All routine hemodialysis patients in one regional hospital were included except for six patients refusing ABI examinations and four patients with atrial fibrillation. Finally, 225 patients formed our study group. The study subjects were observed from arteriovenous access creation until the first episode of VAF. The mean observation period was 42.2 +/- 42.8 mo. The relative VAF risk was analyzed by Cox-regression methods with adjustments for demographic and comorbid conditions. RESULTS VAF episodes were recorded in 111 patients. In multivariate analysis, ABI <0.9 (hazard ratio, 1.893; P = 0.039), vascular access type of arteriovenous graft (P = 0.004), and serum triglyceride level (P = 0.043) were positively associated with VAF, and serum parathyroid hormone level (P = 0.043) was negatively associated with VAF. CONCLUSIONS Our findings show that ABI <0.9 is significantly correlated with increased VAF. Screening hemodialysis patients by means of ABI may help to identify a high-risk group for VAF.

Left Ventricular Tei Index: Comparison between Flow and Tissue Doppler Analyses

Background: It is still unknown whether a correlation exists between left ventricular Tei index obtained by tissue Doppler imaging and that determined by flow Doppler waveforms. This study was conducted to evaluate their relationship and to assess the positional effect on them. Methods: Twenty‐six healthy subjects and 25 patients with essential hypertension were included. On the tissue Doppler images, the time interval from the end to the onset of the mitral annular velocity pattern during diastole and the duration of the S‐wave were used to calculate tissue Doppler Tei index. Results: The tissue Doppler Tei index correlated with the flow Doppler Tei index at sitting position (r = 0.406, P = 0.003), but not at left lateral decubitus position. The limits of agreement for the Tei index measured by both methods were −0.26 to 0.62 at left lateral decubitus position and −0.09 to 0.55 at sitting position. Preload reduction associated with sitting position with dangling feet raised the Tei index both in the healthy controls [0.54 (0.14) vs 0.42 (0.12), P < 0.001] and in the hypertensives [0.53 (0.15) vs 0.46 (0.12), P = 0.005]. There was a similar positional effect on the tissue Doppler Tei index in the control subjects [0.75 (0.12) vs 0.53 (0.10), P < 0.001]. Conclusions: Tissue Doppler Tei index does not seem to be a suitable substitute for flow Doppler Tei index. Flow Doppler Tei index is preload dependent and the loading status should be taken into consideration at the application of Tei index to the evaluation of myocardial performance.

Measuring Left Ventricular Peak Longitudinal Systolic Strain from a Single Beat in Atrial Fibrillation: Validation of the Index Beat Method

BACKGROUND It is traditionally difficult to estimate left ventricular (LV) systolic function in atrial fibrillation (AF). The aim of this study was to validate the use of an index beat, the beat after the nearly equal preceding (RR1) and pre-preceding (RR2) intervals, for the measurement of LV peak longitudinal systolic strain (PLSS). The difference between RR1 and RR2 intervals of the index beat must be <60 msec. LV PLSS measured from the index beat (PLSSindex) was compared with LV PLSS measured from the conventional but time-consuming method of averaging multiple cardiac cycles (PLSSavg). METHODS Ninety-eight patients with persistent or permanent AF and resting ventricular rates ≤ 105 beats/min were prospectively included. LV PLSSindex and LV PLSSavg were obtained from two-dimensional speckle-tracking echocardiography. RESULTS LV PLSSindex had a highly significant correlation with LV PLSSavg (r = 0.970, P < .001). Bland-Altman analysis showed only small bias of 0.01%, and the 95% limits of agreement were +1.64% to -1.62%. Compared with those with lower risk scores of stroke indicated by CHADS(2) scores < 2 or CHA(2)DS(2)-VASc scores < 2, patients with higher risk scores of stroke indicated by CHADS(2) scores ≥ 2 or CHA(2)DS(2)-VASc scores ≥ 2 had lower PLSSavg and PLSSindex (P ≤ .012). CONCLUSIONS LV PLSSindex was a good alternative to LV PLSSavg in patients with AF. Use of the index beat to measure LV longitudinal systolic strain in patients with AF was as accurate as the time-consuming method of averaging multiple cardiac cycles.

Influence of different measurement time points on brachial-ankle pulse wave velocity and ankle-brachial index in hemodialysis patients.

In order to ensure that they are reliable markers of atherosclerosis and suitable for repetitive follow-up of disease progression and management responses in hemodialysis (HD) patients, brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI) should be tested to see whether they change with different measurement time points. The aim of this study was to assess whether baPWV and ABI vary according to whether they are measured before HD, after HD, or on the next dialysis-free day. Eighty-nine patients undergoing regular HD were enrolled. The baPWV and ABI were measured 10–30 min before and after HD, and if patients agreed, on the next dialysis-free day. The third measurement of baPWV and ABI, performed 22±2 h after HD, was taken in 72 patients (81%). The body weight reduction after HD was 2.5±0.9 kg (p<0.001). The brachial and ankle systolic and diastolic blood pressures before HD were significantly higher than those after HD and on the next dialysis-free day (p≤0.038). Right and left baPWV increased significantly after HD (p≤0.006), but returned to the pre-dialysis level on the next dialysis-free day. However, the right and left ABI remained constant before and after HD, or on the next dialysis-free day (p≥0.498). In conclusion, despite the significant decrease in body weight and blood pressures, baPWV increased significantly after HD. In addition, baPWV, but not ABI, may vary at different measurement time points. Therefore, baPWV, but not ABI, should be assessed in a timely manner in HD patients.

Effects of Heart Rate on Brachial-Ankle Pulse Wave Velocity and Ankle-Brachial Pressure Index in Patients Without Significant Organic Heart Disease

This study evaluated the effects of heart rate (HR) on brachial-ankle pulse wave velocity (baPWV) and ankle-brachial pressure index (ABI). Thirty-two patients without significant organic heart disease underwent elective cardiac catheterization or electrophysiologic study, and were then enrolled in right atrial pacing (RAP; 11 men, 9 women; aged 48 ∓15 years) or right ventricular pacing (RVP; 6 men, 6 women, aged 45 ∓13 years) studies. Three different HR levels (90, 100, and 110 beats per minute) were paced in random order. By stepwise, multiple linear regression analysis, age, systolic blood pressure (SBP), and pulse pressure (PP) correlated positively with baseline baPWV. In the RAP group, as HR increased, baPWV and left brachial diastolic blood pressure increased significantly (p ≤0.015), while ABI, left ankle SBP, left brachial PP, and left ankle PP decreased significantly (p ≤0.013). In the RVP group, as HR increased, baPWV also increased significantly (p=0.001), while ABI, left ankle SBP, and PP decreased significantly (p ≤ 0.034). Values of baPWV and ABI may be influenced by HR in young and middle-aged patients without significant organic heart disease. When these values are used to evaluate and follow up cardiovascular risk in patients, HR changes should be considered.