Reproducibility of the ambulatory arterial stiffness index in hypertensive patients

Mixed circuit training acutely reduces arterial stiffness in patients with chronic stroke: a crossover randomized controlled trial

PURPOSE

Investigate whether a single bout of mixed circuit training (MCT) can elicit changes in arterial stiffness in patients with chronic stroke. Second, to assess the between-day reproducibility of post-MCT arterial stiffness measurements.

METHODS

Seven participants (58 ± 12 years) performed a non-exercise control session (CTL) and two bouts of MCT on separate days in a randomized counterbalanced order. The MCT involved 3 sets of 15 repetition maximum for 10 exercises, with each set separated by 45-s of walking. Brachial-radial pulse wave velocity (br-PWV), radial artery compliance (AC) and reflection index (RI_1,2) were assessed 10 min before and 60 min after CTL and MCT. Ambulatory arterial stiffness index (AASI) was calculated from 24-h recovery ambulatory blood pressure monitoring.

RESULTS

Compared to CTL, after 60 min of recovery from the 1st and 2nd bouts of MCT, lower values were observed for br-PWV (mean diff = - 3.9 and - 3.7 m/s, respectively, P < 0.01; ICC_2,1 = 0.75) and RI_1,2 (mean diff = - 16.1 and - 16.0%, respectively, P < 0.05; ICC_2,1 = 0.83) concomitant with higher AC (mean diff = 1.2 and 1.0 × 10^-6 cm⁵/dyna, respectively, P < 0.01; ICC_2,1 = 0.40). The 24-h AASI was reduced after bouts of MCT vs. CTL (1st and 2nd bouts of MCT vs. CTL: mean diff = - 0.32 and - 0.29 units, respectively, P < 0.001; ICC_2,1 = 0.64).

CONCLUSION

A single bout of MCT reduces arterial stiffness during laboratory (60 min) and ambulatory (24 h) recovery phases in patients with chronic stroke with moderate-to-high reproducibility.

TRIAL REGISTRATION

Ensaiosclinicos.gov.br identifier RBR-5dn5zd.

Long-term variability of impulse oscillometry and spirometry in stable COPD and asthma

Background

While optimizing spirometry is a challenge for lung function labs, long-term variability if any between IOS (impulse oscillometry) parameters and spirometry is not clearly known in stable COPD (chronic obstructive pulmonary disease) and chronic asthma. The forced oscillation technique is increasingly employed in routine lung function testing. Our aim in this study was to determine the variability in oscillometric parameters between clinic visits over weeks or months in two patient groups during a period of clinical stability. Moreover, the research assessed relationships between IOS parameters long-term variability and COPD severity.

Methods

We used data from 73 patients with stable COPD and 119 patients with stable asthma at the Shanghai Pulmonary Hospital Affiliated to Tongji University. Patients were included if they had three or more clinic visits where spirometry and IOS were performed during a clinically stable period. Data recorded from the first three visits were used. The standard deviation (SDbv), the coefficient of variation (COV), intraclass correlation coefficient (ICC) and the coefficient of repeatability (COR) were calculated, Wilcoxon Mann–Whitney test was used for data that did not conform to normality of distributions, Kruskal Wallis test was used to compare with multiple groups, post hoc comparison was analyzed by Bonferroni, Spearman correlation coefficients for non-parametric data, the multiple regression analyses to determine the relationship between long-term variability and airflow obstruction.

Results

(1) The repeatability of IOS resistance parameters with ICC values > 0.8 was high in COPD and asthma. ICC values of IOS resistance parameters were higher than IOS reactance parameters; (2) the repeatability of spirometry parameters with ICC values < 0.8 was lower than IOS resistance parameters in different GOLD (the Global Initiative for Chronic Obstructive Lung Disease) stages, the higher the stage the worse the repeatability; (3) the severity of airflow obstruction was correlated with long-term variability of R5 (R at 5 Hz) (P < 0.05) in GOLD4, not with long-term variability of R20 (R at 20 Hz) (P > 0.05) and R5-R20 (P > 0.05).

Conclusion

IOS resistance parameters have good long-term repeatability in asthma and COPD. Additionally, repeatability of spirometry parameters is lower than IOS resistance parameters in different GOLD stages.

The Relationship Between Ambulatory Arterial Stiffness Index and Cardiovascular Outcomes in Women

Background

The ambulatory arterial stiffness index (AASI) obtained during ambulatory blood pressure monitoring (ABPM) has been cited as an independent predictor of major adverse cardiovascular events (MACEs) including cardiovascular death, stroke and worsening chronic kidney disease (CKD) among mixed-sex adult populations. This study aimed to determine the relationship between AASI and MACE and its predictive precision in women.

Methods

This work follows the guidelines of the STROBE initiative for cohort studies. This was a retrospective single-center observational study of adult women (aged 18 - 75 years), who underwent 24-h ABPM for the diagnosis of hypertension or its control. The primary endpoint was a composite MACE of cardiovascular death, acute limb ischemia, stroke, acute coronary syndrome (ACS), or progression to stage V CKD.

Results

A total of 219 women aged 57.4 ± 13.3 years were followed up for a median (interquartile range (IQR)) of 25.5 (18.3 - 31.3) months. Overall, 16 (7.3%) patients suffered one or more MACE events. AASI was significantly higher in patients with known coronary artery disease (CAD), diabetes mellitus, peripheral vascular disease (PVD), heart failure, previous stroke, or transient ischemic attack (TIA). AASI was a significant predictor of MACE (area under the curve: 0.78; P < 0.001) with an optimal cut-off of ≥ 0.56. On Kaplan-Meier analysis AASI ≥ 0.56 was significantly associated with MACE (log-rank test, P < 0.001). The only independent predictors of MACE on Cox proportional hazard analysis were diabetes mellitus, low high-density lipoprotein (HDL) levels, cumulative AASI values, or AASI ≥ 0.56.

Conclusions

An AASI of ≥ 0.56 is an independent predictor of MACE in women. A further validation study in a larger cohort of women is recommended.

Short-term reproducibility of the 24-h ambulatory monitoring of brachial and central hemodynamics in untreated Chinese

Objective: Advanced technology allows non-invasive monitoring of the 24-h brachial and central hemodynamics simultaneously. However, related reproducibility data was limited in White patients. We therefore explored if the novel measurements would be reproducible in Chinese. Methods: From February 2017 to January 2018, 152 untreated patients who were suspected of hypertension and referred for ambulatory blood pressure (BP) monitoring were recruited. Ambulatory BP monitoring was repeated within one month (median, 12.5 days) using the Mobil-O-Graph monitors (IEM, Germany). Reproducibility was assessed as the intra-class correlation coefficient (ICC), coefficient of variation (CV), and repeatability coefficient (RC). Results: The 152 participants (average age, 58.6 years) included 54 men and 98 women. The first and second means of the ambulatory brachial and central BPs, pulse wave velocity (PWV), augmentation pressure, augmentation index (AIx) and AIx at a heart rate of 75 beats per minute (AIx@75) were all similar (p ≥ 0.065), except that the repeated daytime and 24-h brachial and central systolic BPs and pulse pressure slightly differed by approximately 1-2 mmHg (p ≤ 0.011). ICC ranged from 0.70 to 0.94 for all ambulatory BPs and ≥0.91 for the arterial measurements. CV was in the range from 5.0% to 10.3% for all BPs and PWV measurements, and from 15.5% to 22.3% for AIx and AIx@75. RC expressed as percentages of maximal variation was <15% for the PWVs and ranged from 25.5% to 54.7% for BPs, AIx and AIx@75. Conclusions: The 24-h ambulatory brachial and central BPs and arterial measurements were reproducible within a short time period in Chinese, and could therefore be used in clinical practice and research settings.

Ambulatory arterial stiffness index correlates with ambulatory pulse pressure but not dipping status in patients with grade 1/grade 2 essential hypertension

OBJECTIVE

To evaluate the relationship between ambulatory arterial stiffness index (AASI) and other parameters derived from ambulatory blood pressure (BP) monitoring, including dipping status, in patients with grade 1/grade 2 hypertension.

METHODS

This retrospective analysis included baseline data from Chinese outpatients enrolled into a previous study, who had clinic diastolic BP of 90-109 mmHg and systolic BP <180 mmHg, had undergone 24-h ambulatory BP monitoring and routine blood chemistry investigations, and had estimated glomerular filtration rate (eGFR) data.

RESULTS

Out of 120 patients screened, 87 were included. No significant difference in 24-h AASI was found between dippers and nondippers. The 24-h AASI significantly correlated with age, systolic BP and pulse pressure, and inversely correlated with 24-h diastolic BP variation and eGFR. In dippers and nondippers, AASI correlated with daytime pulse pressure, daytime diastolic BP variation and eGFR; in nondippers, AASI also correlated with 24-h systolic BP and 24-h pulse pressure. The 24-h AASI was significantly associated with 24-h pulse pressure and daytime pulse pressure.

CONCLUSION

In patients with grade 1/grade 2 essential hypertension, AASI shows a significant correlation with ambulatory pulse pressure.

Association of changes in ambulatory arterial stiffness index and pulse wave velocity during antihypertensive treatment: the J-CORE study

BACKGROUND

We aimed to investigate the association of the change in the ambulatory arterial stiffness index (AASI) with that in carotid-femoral pulse wave velocity (cfPWV) during treatment with antihypertensive medication.

METHODS

We enrolled 207 hypertensive patients treated with olmesartan monotherapy for 12 weeks. Patients were randomly assigned to treatment with hydrochlorothiazide (HCTZ; n = 104) or azelnidipine (n = 103) for 24 weeks. The cfPWV and 24-h ambulatory blood pressure monitoring (ABPM) results were assessed at baseline and 24 weeks later. The AASI was defined as 1 minus the regression slope of diastolic blood pressure (DBP) on systolic BP (SBP), and was calculated by standard and symmetric regression.

RESULTS

The changes in the AASI and symmetrical AASI were similar between the two groups, while cfPWV in the azelnidipine group decreased more than in the HCTZ group (P < 0.001). The change in AASI was not significantly correlated with change in cfPWV (r = 0.08, P = 0.26), whereas the change in symmetrical AASI was significantly but weakly correlated with change in cfPWV (r = 0.22, P < 0.001). The multivariable linear regression analysis revealed that the association of the change in symmetrical AASI with change in cfPWV remained significant even after adjustments for covariates derived from ABPM (regression coefficient (95% confidence interval): 1.33 (0.35-2.30), P = 0.01).

CONCLUSIONS

The present study demonstrated that neither AASI nor symmetrical AASI may be an unequivocal marker of arterial stiffness during antihypertensive treatment.

Ambulatory arterial stiffness index is higher in hypertensive patients with chronic kidney disease

Ambulatory arterial stiffness index (AASI) is a parameter obtained from ambulatory blood pressure monitoring (ABPM) that correlates with clinical endpoints. The aim of this study was to compare AASI in nondiabetic hypertensive patients with and without chronic kidney disease (CKD). Subjects with systemic arterial hypertension (SAH, n = 30) with normal renal function, aged 40 to 75 years, were compared to hypertensive patients with CKD (n = 30) presenting estimated glomerular filtration rate (eGFR) <60 mL/min by MDRD formula. ABPM was carried out in all patients. In CKD group, eGFR was 35.3 ± 2.8 ml/min. The mean 24-hour systolic and diastolic blood pressure (BP) was similar in both groups. AASI was significantly higher in CKD group (0.45 ± 0.03 versus 0.37 ± 0.02, P < 0.05), positively correlated to age (r = 0.38, P < 0.01) and pulse pressure (r = 0.43, P < 0.01) and negatively correlated to nocturnal BP fall (r = -0.28, P = 0.03). These findings indicate the presence of stiffer vessels in CKD hypertensive patients.

Ambulatory arterial stiffness index in chronic kidney disease stage 2-5. Reproducibility and relationship with pulse wave parameters and kidney function

BACKGROUND

Arterial stiffness contributes to the increased cardiovascular risk in patients with chronic kidney disease (CKD). Reproducible and easily obtainable indices of arterial stiffness are needed in order to monitor therapeutic strategies. The ambulatory arterial stiffness index (AASI) has been proposed as such a marker. The present study investigated the day-to-day reproducibility of AASI in CKD stage 2-5 and its relationship with other markers of arterial stiffness as well as with kidney function.

METHODS

Eighty-three patients (29% female, median age 62 years) were studied by 24 h ambulatory blood pressure monitoring (ABPM), aortic pulse wave velocity (aPWV), augmentation index (AIx) and estimated glomerular filtration rate (eGFR) at a median interval of 7 days. Individual AASIs were calculated from 24 h ABPMs as 1 minus the regression slope of diastolic blood pressure over systolic blood pressure.

RESULTS

Mean AASI, aPWV, AIx and 24 h pulse pressure (PP) were similar on repeated measurements. The intraclass correlation coefficients were between 72% and 78% for AASI calculated by three different methods, 87% for aPWV, 88% for AIx, and 96% for 24 h PP. The correlation coefficients between AASI and aPWV were from 0.48 to 0.53; with AIx it was between 0.19 and 0.34. After adjustment for covariates none of the arterial stiffness indices were significantly correlated to eGFR.

CONCLUSIONS

In patients with CKD stage 2-5 AASI had a moderate, but acceptable reproducibility. The correlation between AASI and aPWV was good whilst the correlation between AASI and AIx was considerably lower. There was no significant correlation between AASI and eGFR.

Ambulatory arterial stiffness indexes in acromegaly

OBJECTIVE

Acromegaly is associated with increased cardiovascular morbidity and mortality and with specific heart and vascular abnormalities. The aim of our study was to investigate arterial stiffness using the ambulatory arterial stiffness index (AASI) and symmetric AASI (Sym-AASI), two indexes derived from 24-h ambulatory blood pressure monitoring (ABPM), in a group of normotensive and hypertensive patients with active acromegaly, compared with normotensive controls (NOR-CTR) or hypertensive controls (HYP-CTR).

SUBJECTS AND METHODS

Ninety-six consecutive patients with active acromegaly (46 males, mean age 49±14 years) underwent 24-h ABPM and evaluation of cardiovascular risk factors. Based on ABPM measurement, acromegalic patients were divided into 64 normotensive (normotensive acromegalic patients (NOR-ACRO)) and 32 hypertensive (hypertensive acromegalic patients (HYP-ACRO)) patients, and were compared with 35 normotensive (NOR-CTR) and 34 hypertensive (HYP-CTR) age-, sex,- and ABPM-matched control subjects.

RESULTS

The AASI and Sym-AASI indexes were significantly higher in acromegalic patients than in controls, either in the normotensive (NOR-ACRO vs NOR-CTR, P<0.0001 for AASI and P=0.005 for Sym-AASI) or in the hypertensive (HYP-ACRO vs HYP-CTR, P=0.01 for AASI and P=0.01 for Sym-AASI) group. Multiple logistic regression analysis showed a significant association of the highest AASI tertile with serum IGF1 (P=0.034) in the whole acromegalic group.

CONCLUSION

AASIs are increased in acromegaly, independent of blood pressure (BP) elevation, and may have an important role in predicting cardiovascular risk in this disease.

Prognostic impact of the ambulatory arterial stiffness index in resistant hypertension

OBJECTIVE

The ambulatory arterial stiffness index (AASI), derived from ambulatory blood pressure (BP) monitoring recordings, is an indirect marker of arterial stiffness and a potential predictor of cardiovascular risk. Resistant hypertension is defined as uncontrolled office BP despite the use of at least three antihypertensive drugs. The aim of this prospective study was to investigate the AASI prognostic value in patients with resistant hypertension.

METHODS

At baseline, 547 patients underwent clinical-laboratory, and 24-h ambulatory BP monitoring examinations. AASI was defined as 1 minus the regression slope of DBP on SBP, and was calculated by standard and symmetric regression. Primary endpoints were a composite of fatal and nonfatal cardiovascular events and all-cause and cardiovascular mortalities. Multiple Cox regression was used to assess associations between AASI and subsequent endpoints.

RESULTS

After median follow-up of 4.8 years, 101 patients (18.4%) reached the primary endpoint, and 65 all-cause deaths (11.9%) occurred (45 from cardiovascular causes). 24-h AASI was the best independent predictor of composite endpoint (hazard ratio 1.46, 95% confidence interval 1.12-1.92, for increments of 1-SD = 0.14), whereas cardiovascular mortality was best predicted by night-time AASI (hazard ratio 1.73, 95% confidence interval 1.13-2.65), after adjustments for cardiovascular risk factors, including mean ambulatory BPs and nocturnal BP reduction. Symmetric AASI was not superior to standard AASI. In sensitivity analysis, 24-h AASI was a better predictor of cardiovascular outcomes in women, in younger individuals, and in nondiabetic individuals.

CONCLUSION

AASI is a predictor of cardiovascular morbidity and mortality in resistant hypertension, over and beyond traditional risk factors and other ambulatory BP monitoring parameters.

Ambulatory arterial stiffness index: reproducibility of different definitions

BACKGROUND

Ambulatory arterial stiffness index (AASI) has been proposed as a marker of arterial stiffness, which predicts cardiovascular mortality. This study compared the reproducibility of 24-h, daytime, night time, and symmetrical AASI.

METHODS

A total of 126 untreated hypertensives (mean age 48.2 +/- 10.7 (s.d.) years, 70 men) underwent 24-h ambulatory blood pressure (ABP) monitoring twice 2-4 weeks apart. The reproducibility of AASI was assessed using the following criteria: (i) repeatability coefficient (RC = 2 x s.d. of differences); (ii) RC expressed as a percentage of close to maximal variation (pMV = RC/(4 x s.d. of the mean of paired recordings)); (iii) coefficient of variation (CV); (iv) concordance correlation coefficient (CCC); (v) agreement (kappa) between the two AASI measurements to detect subjects at the top quartile of the respective AASI distributions.

RESULTS

There was no difference in average AASI values between the two assessments. For 24-h, daytime, night time, and symmetrical AASI, respectively, (i) RC values were 0.24, 0.38, 0.42, and 0.30; (ii) pMV 49.6, 68.8, 73.9, and 56; (iii) CV 40.3, 39.3, 62.9, and 116.3; (iv) CCC 0.60, 0.35, 0.28, and 0.52; (v) agreement 82.5% (kappa 0.54), 72.2% (0.28), 73% (0.22), and 81.7% (0.50). Differences in 24-h mean arterial ambulatory pressure (MAP) and in nocturnal MAP decline between the two assessments were significant determinants of the differences in 24-h and symmetrical AASI values.

CONCLUSIONS

Although no differences were found in average AASI values of the two ambulatory recordings, significant differences were observed in their reproducibility, with 24-h AASI being the most reproducible measure in terms of all the examined criteria.American Journal of Hypertension 2010; doi:10.1038/ajh.2009.217.