Arterial pathophysiology and comparison of two devices for pulse wave velocity assessment in elderly men: the British regional heart study

Comparing oscillometric and tonometric methods to assess pulse wave velocity: a population-based study

BACKGROUND

Oscillometric pulse wave velocity (o-PWV) represents an attractive, non invasive and non operator-dependent method to estimate arterial stiffness. Tonometric carotid-femoral measurements (cf-PWV),are considered the gold-standard for non-invasive aortic stiffness assessment. To date, no studies in the general population comparing the two methods have been performed.

METHODS AND RESULTS

1162 subjects were analysed. O-PWV and cf-PWV showed a mean difference of -0.31 m/sec(p ≤ 0.001). No significant differences between cf-PWV and o-PWVs were observed in patients without cardiovascular risk factors. The Bland and Altman analysis showed a moderate agreement between 24 h-o-PWV and cf-PWV (mean difference -0.99, LoA 4.23 to -6.22m/s). O-PWVs underestimate and overestimate arterial stiffness under and over 50 years respectively(p ≤ 0.001). Systolic blood pressure (SBP) and age differently impact cf-PWV and in office o-PWV variability (r2 0.35 and 0.88 respectively). In younger subjects a strong relationship between o-PWV and SBP reducing as age increases was found. Analysing the impact of age, an opposite trend was noticed.

CONCLUSIONS

Oscillometric PWV estimates provide reliable values in the general population. An o-PWV tendency to underestimate arterial stiffness in younger subjects and in subjects with diseases known to increase arterial stiffness and to overestimate it with increasing age was found, even if scarcely relevant in clinical perspective. Overall the present findings underline an acceptable and satisfactory agreement between oscillometric and tonometric methods for the PWV assessment. KEY MESSAGES Oscillometric and tonometric PWV estimates showed a good and satisfactory agreement in the general population, above all in subjects without cardiovascular risk factors or a documented vascular damage. In comparison with tonometric values, oscillometric PWV estimates showed, however, the tendency to underestimate arterial stiffness in younger subjects and to overestimate it with increasing age, while diverging when diseases known to increase arterial stiffness are present. The magnitude of differences in PWV estimates between tonometric and oscillometric methods found in the general population appears most likely not to be significant in everyday clinical practice.

Subclinical cardiovascular disease and risk of incident frailty: The British Regional Heart Study

BACKGROUND/OBJECTIVES

Subclinical cardiovascular disease (CVD) is cross-sectionally associated with frailty, but the relationship between subclinical CVD and incident frailty has not been reported. We aimed to assess this prospective association.

DESIGN

Longitudinal analysis of data from the British Regional Heart Study, a prospective cohort study.

PARTICIPANTS

1057 men, aged 71-92 years, robust or pre-frail at baseline, and without a clinical diagnosis of CVD.

MEASUREMENTS

Participants underwent baseline measurement of carotid-femoral pulse wave velocity (cfPWV), carotid intima-media thickness (CIMT), carotid distensibility coefficient (DC), and ankle-brachial pressure index (ABPI), and had questionnaire-based frailty assessment after three years. Frailty status was based on the Fried phenotype. Multivariate logistic regressions examined associations between incident frailty and tertile of cfPWV, CIMT, DC, and ABPI group (<0.9, 0.9-1.4, ≥1.4).

RESULTS

865 men were examined and completed the 3 year follow-up questionnaire, of whom 78 became frail. Adjusted for age, prefrailty, body mass index, diabetes, smoking, atrial fibrillation, blood pressure, renal function, and incident CVD, higher CIMT was associated with greater odds of incident frailty (2nd tertile OR 1.62, 95% CI 0.78-3.35, 3rd tertile OR 2.61, 95% CI 1.30-5.23, p = 0.007, trend p = 0.006). cfPWV showed a weaker, non-significant association (2nd tertile OR 1.79, 95% CI 0.85-3.78, 3rd tertile OR 1.73, OR 0.81-3.72, p = 0.16, trend p = 0.20). There was no clear association between incident frailty and DC or ABPI. In subgroup analyses, CIMT was significantly associated with incident frailty in men ≥80 years (3rd tertile OR 6.99, 95%CI 1.42-34.5), but not in men aged 75-80 or < 75 years.

CONCLUSION

Subclinical CVD, as measured by CIMT, is associated with greater risk of incident frailty in older men over three year follow-up, independent of the development of clinically-apparent stroke, heart failure, or myocardial infarction, and may be a modifiable risk factor for frailty. This association may be stronger in very old age.

Serum indoxyl sulfate as a potential biomarker of aortic arterial stiffness in coronary artery disease

BACKGROUND AND AIMS

Indoxyl sulfate (IS), a dietary tryptophan metabolite, acts as a cardiotoxin and uremic toxin. High IS levels are associated with chronic kidney disease and cardiovascular diseases. This study investigated the association between serum IS levels and aortic arterial stiffness (AAS) in coronary artery disease (CAD) patients.

METHODS AND RESULTS

The carotid-femoral pulse wave velocity (cfPWV) was measured by the SphygmoCor system and patients with values of >10 m/s were classified in the AAS group. The baseline characteristics were recorded and measured (including biochemical and clinical data). Serum IS levels were determined using liquid chromatography-mass spectrometry. AAS occurred in 50 (34.7%) of 144 patients with CAD. They were older, had higher IS levels and percentages of diabetes, systolic blood pressure, blood urea nitrogen, and creatinine but lower estimated glomerular filtration rates. The IS level and older age significantly correlated with AAS [odds ratio (OR) = 3.834, p = 0.031; OR = 1.095, p = 0.002, respectively]. Furthermore, the serum IS level (β = 0.167, adjusted R² change: 0.026, p = 0.027) had a significant positive correlation with cfPWV.

CONCLUSIONS

Taken together, higher serum IS levels are potential independent biomarkers for AAS in patients with CAD. Therefore, early checking of serum IS levels may help prevent CAD progression and have clinical implications in the near future.

Ethnic differences in subclinical vascular function in South Asians, Whites, and African Americans in the United States

BACKGROUND

South Asians are a high-risk ethnic group for cardiovascular disease despite having lower levels of conventional cardiovascular risk factors such as obesity and smoking. Ethnic differences in pulse wave reflections, arterial stiffness, and subclinical atherosclerosis as measured using augmentation index (AIX), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT) may reflect some of this excess risk.

METHODS

We conducted a cross-sectional analysis of pooled data from three community-based sources in Atlanta, Georgia, USA. Data on 530 South Asians collected from local health fairs was compared with data on 507 White and 192 African Americans from the Emory Predictive Health Initiative and 351 White and 382 African Americans from the Morehouse and Emory Team up to Eliminate Health Disparities Study.

RESULTS

Linear regression models adjusted for age, sex, smoking, MAP, fasting glucose, TC, HDL-C, creatinine, and body mass index were used to assess the relationship between ethnicity and vascular function measures. In fully adjusted models, South Asians had higher heart rate corrected AIX as compared with Whites and African Americans (by 5.47%, p < 0.01 and 3.50%, p < 0.01; respectively), but lower PWV (by 0.51 m/s, p < 0.01 and 0.72 m/s, p < 0.01; respectively) and lower CIMT (by 0.02 mm p = 0.03 and 0.04 mm p < 0.01; respectively).

CONCLUSIONS

Systemic pulse wave reflections, independent of other risk factors, are higher in South Asians as compared with Whites and African Americans. Future research is needed to determine whether higher AIX explains the increased cardiovascular risk among South Asians.

Response of peripheral arterial pulse wave velocity to acute exercise in patients after recent myocardial infarction and healthy controls

Background

Many studies found increased central arterial stiffness and poor endothelial function in patients with coronary artery disease (CAD). Acute exercise has been shown to decrease peripheral pulse wave velocity (pPWV) in young healthy volunteers. We hypothesized the response to acute exercise to be diminished in CAD patients compared to healthy young (HY) and age-matched (HAM) controls.

Methods

In 21 patients after recent myocardial infarction (CAD), 11 HAM and 10 HY pPWV was measured by applanation tonometry at the proximal femoral artery and the posterior tibial artery at rest and from 5 to 15 min after cessation of exhaustive exercise. Heart rate (HR) and blood pressure (BP) were monitored continuously. Resting central PWV (cPWV) was measured between the carotid and femoral arteries. Resting values and reponses to acute exercise were compared between the three groups and predictors for pPWV response were sought.

Results

The response in pPWV to acute exercise seen in HY (lowering in pPWV by 17%) was absent in both CAD and HAM. Resting pPWV was not statistically different between the three groups, while cPWV was comparable in CAD and HAM but 17% lower in HY. Predictors for response in pPWV to exercise were age (Spearman r = 0.48), cPWV (r = 0.34) and response in diastolic BP (r = 0.32).

Conclusion

The response in pPWV to acute exercise observed in HY was absent in CAD and HAM. In dilated peripheral arteries, PWV may reflect stiffness of passive vessel structures, which are likely to increase with age in healthy persons and CAD alike.