Association of pulse wave velocity and pressure wave reflection with the ankle-brachial pressure index in Japanese men not suffering from peripheral artery disease

Preclinical systolic dysfunction relating to ankle-brachial index among high-risk PAD population with preserved left ventricular ejection fraction

Peripheral artery disease (PAD) shares common clinical risk factors, for example, endothelial dysfunction, with preserved ejection fraction (LVEF) heart failure (HFpEF). Whether PAD is associated with preclinical systolic dysfunction and higher HF risk among individuals presenting preserved LVEF remains uncertain. We retrospectively included outpatients with at least one known or established cardiovascular (CV) risk factor with LVEF ≥ 50%. Patients were categorized into high risk and low risk of developing PAD (PAD vs Non-PAD) by ankle-brachial index (ABI) (≤ 0.90 or > 1.4) and further stratified based on their history of HFpEF (HFpEF vs. Non-HFpEF), resulting in the formation of four distinct strata. Preclinical systolic dysfunction was defined using dedicated speckle-tracking algorithm. A total of 2130 consecutive patients were enrolled in the study, with a median follow-up of 4.4 years. The analysis revealed a higher prevalence of high risk of developing PAD in patients with HFpEF compared to those without HFpEF (25.1% vs. 9.4%). Both high risk of developing PAD and HFpEF were independently associated with preclinical systolic dysfunction (global longitudinal strain, GLS ≥ - 18%) (odds ratio, OR: 1.38; 95% confidence interval, CI: 1.03-1.86). In comparison to patients at low risk of developing PAD without HFpEF (Non-PAD/Non-HFpEF group), those categorized as having a high risk of developing PAD with HFpEF (PAD/HFpEF group) exhibited the most impaired GLS and a heightened susceptibility to heart failure hospitalization (hazard ratio, HR: 6.51; 95% CI: 4.43-9.55), a twofold increased risk of all-cause mortality (HR: 2.01; 95% CI: 1.17-3.38), cardiovascular mortality (HR: 2.44; 95% CI: 1.08-5.51), and non-cardiovascular mortality (HR: 1.78; 95% CI: 0.82-3.84). A high risk of developing PAD was strongly linked to impaired preclinical systolic function and an increased likelihood for subsequent hospitalization for HF, all-cause mortality, CV mortality and non-CV mortality. There is a clear need for preventive strategies aimed at reducing hospitalizations for HF and mortality in this high-risk population.

Relationship of blood pressure measured in the calf with arm blood pressure and arterial stiffness: a general population study

AIM

Leg blood pressure (BP) measurement is needed when arm BP evaluation is not feasible, and calf BP, especially when measured in standing position, may have greater association with cardiovascular remodeling than arm BP. This study evaluated the relationship between calf and arm BP, and investigated whether calf BP would be superior to arm BP in predicting increased arterial stiffness [pulse wave velocity (PWV) > 10 m/s].

METHODS

We evaluated clinical and laboratory characteristics, BP measurements, and PWV in 1397 individuals resident in Baependi, Brazil, between 2017 and 2019. Arm BP was measured in the seated and supine positions while calf BP was measured in supine and standing positions using digital oscillometric devices. Carotid-femoral PWV was measured using a noninvasive mechanotransducer.

RESULTS

The sample had 62.7% females, age = 48.1 ± 15.4 years and 8.4% with PWV >10 m/s. Results of linear regression analysis showed that BP values of 140/90 mmHg measured in the arm in supine and seated position were equivalent to calf supine BP values of 164/81 mmHg and 166/78 mmHg and calf standing BP values of 217/137 mmHg and 221/137 mmHg, respectively. Calf-arm BP differences were associated with age, glomerular filtration rate, body mass index, smoking, low-density lipoprotein-cholesterol, diabetes and height. Furthermore, stepwise logistic regression analysis revealed that arm supine systolic BP, but not calf BP measurements, was independently associated with increased arterial stiffness.

CONCLUSION

Thresholds of ≈165/80 mmHg and ≈220/135 mmHg could be used for diagnosing hypertension when only calf measurements in supine and standing positions, respectively, are available. Conversely, calf BP was not superior to arm BP in predicting increased arterial stiffness.

A cross-sectional study in type 2 diabetes patients reveals that elevated pulse wave velocity predicts asymptomatic peripheral arterial disease associated with age and diabetes duration

Background

Peripheral arterial disease (PAD) reduces functional capacity and raises cardiovascular risks, but underdiagnosis is common, resulting in less comprehensive care than other cardiovascular conditions. While diabetes has long been viewed as a key risk factor for PAD, recent studies indicate that its impact is influenced by the presence of concurrent cardiovascular risk factors. The aim of this study is to elucidate the intricate relationship between the prevalence of PAD, diabetic complications, and cardiovascular risk factors among asymptomatic patients with type 2 diabetes mellitus (T2DM).

Methods

Ninety-one patients with T2DM and no symptoms or previous diagnosis of PAD were recruited from the outpatient diabetic clinic. Clinical data were extracted from electronic medical records, and the screening for PAD was conducted using MESI mTABLET.

Results

Screening for PAD among asymptomatic individuals with T2DM revealed that 5.49 % of patients exhibit a low ankle-brachial index (ABI). Patients who had previously experienced major adverse cardiovascular events or exhibited albuminuria displayed lower ABI values. Furthermore, a striking 45.05 % of the participants displayed an abnormally high carotid-femoral pulse wave velocity (cfPWV) value, with elevated PWV values correlating with advanced age and longer diabetes duration.

Conclusions

The prevalence of elevated cfPWV is more pronounced than that of decreased ABI in T2DM patients with asymptomatic PAD and is associated with older age and longer diabetes duration, therefore measurement of both ABI and PWV is crucial for the cardiovascular risk assessment protocol for patients with T2DM and timely PAD diagnosis.

Paradox of the Relationship between Cardio-Ankle Vascular Index and Ankle-Brachial Index in Patients with Lower Extremity Artery Disease

Objectives: Measurements of ankle-brachial index (ABI) and toe-brachial index (TBI) are standard examinations for evaluating arterial blood flow in lower extremities and diagnosing lower extremity artery disease (LEAD). It remains to be clarified whether cardio-ankle vascular index (CAVI), a blood pressure-independent parameter of arterial stiffness, is associated with ABI and TBI in patients with LEAD. Methods: The subjects were 165 outpatients with LEAD. Arterial blood flow in lower extremities was evaluated by using ABI, TBI, and the degree of leg exercise-induced reduction of ABI (%). Results: CAVI showed significant positive correlations with ABI and TBI and showed significant inverse correlations with exercise-induced % decrease in ABI. CAVI was significantly higher in the 3rd tertile groups of ABI and TBI than that in the corresponding 1st tertile groups and was significantly lower in the 3rd tertile group of exercise-induced % decrease in ABI than that in the 1st tertile group. The above relationships remained significant after adjustment for age, body mass index, blood pressure, diabetes history, and habitual smoking. Conclusions: Although CAVI is a general parameter reflecting arterial stiffness, CAVI showed paradoxical associations, namely, positive associations with ABI and TBI and an inverse association with exercise-induced % decrease in ABI in patients with LEAD.

Vascular function: a key player in hypertension

The major functions of the arterial system are to "efficiently deliver blood to the peripheral organs and maintain vascular homeostasis". Both the endothelial and medial layer contribute to the three major functions, namely, conversion of pulsatile to steady blood flow, appropriate distribution of blood flow to the target organs, and vascular protection and homeostasis. Vascular dysfunction contributes to the development of cardiovascular diseases through a combination of several mechanisms, including impaired coronary perfusion, cardiac systolic/diastolic dysfunction, microvascular damage, and abnormal hemodynamics in the arterial tree. The representative marker of endothelial function is flow-mediated vasodilatation and that of the medial layer function is pulse wave velocity, and that of the blood supply function of the arterial tree is the ankle-brachial pressure index. In hypertension, vascular dysfunction could also lead to the development of isolated systolic hypertension, isolated diastolic hypertension, and systolic/diastolic hypertension. Vascular dysfunction is involved in a vicious cycle with abnormal blood pressure variability. Furthermore, a vicious cycle may also exist between vascular dysfunction and hypertension. While the significances of vascular function tests to predict future cardiovascular events has been established in cases of hypertension, their usefulness in assessing the effectiveness of management of the vascular functions in hypertension on the cardiovascular outcomes has not yet been fully clarified. Thus, vascular dysfunction plays crucial roles in the pathophysiology of hypertension, and further research is warranted to establish strategies to improve vascular dysfunction in cases of hypertension. Vascular functions in the pathophysiology of hypertension. Vascular dysfunction and elevation of blood pressure are components of a vicious cycle even from their early stages, which including abnormal blood pressure variabilities. This vicious cycle is associated with hypertensive organ damage and also adverse cardiovascular outcomes. Strategies to break this vicious cycle have not yet been fully established.

Combined Evaluation of Arterial Stiffness and Blood Pressure Promotes Risk Stratification of Peripheral Arterial Disease

Background

Previous studies have reported the separate association of arterial stiffness (AS) and blood pressure with peripheral arterial disease (PAD).

Objectives

The aim of this study was to investigate the risk stratification capacity of AS on incident PAD beyond blood pressure status.

Methods

A total of 8,960 participants from Beijing Health Management Cohort were enrolled at the first health visit between 2008 and 2018 and then followed until the incidence of PAD or 2019. Elevated AS was defined as brachial-ankle pulse-wave velocity (baPWV) >1,400 cm/s, including moderate stiffness (1,400 ≤ baPWV <1,800 cm/s) and severe stiffness (baPWV ≥1,800 cm/s). PAD was defined as ankle-brachial index <0.9. A frailty Cox model was used to calculate the HR, integrated discrimination improvement, and net reclassification improvement.

Results

During follow-up, 225 participants (2.5%) developed PAD. After adjusting for confounding factors, the highest risk for PAD was observed in the group with elevated AS and blood pressure (HR: 2.253; 95% CI: 1.472-3.448). Among participants with ideal blood pressure and those with well-controlled hypertension, PAD risk was still significant for severe AS. The results remained consistent in multiple sensitivity analyses. In addition, baPWV significantly improved the predictive capacity for PAD risk beyond systolic and diastolic blood pressures (integrated discrimination improvement 0.020 and 0.190, net reclassification improvement 0.037 and 0.303).

Conclusions

This study suggests the clinical importance of combined evaluation and control of AS and blood pressure for the risk stratification and prevention of PAD.

A personalized 0D-1D model of cardiovascular system for the hemodynamic simulation of enhanced external counterpulsation

BACKGROUND AND OBJECTIVE

Enhanced external counterpulsation (EECP) is a non-invasive treatment modality capable of treating a variety of ischemic diseases. Currently, no effective methods of predicting the patient-specific hemodynamic effects of EECP are available. In this study, a personalized 0D-1D model of the cardiovascular system was developed for hemodynamic simulation to simulate the changes in blood flow in the EECP state and develop the best treatment protocol for each individual.

METHODS

A 0D-1D closed-loop model of the cardiovascular system was developed for hemodynamic simulation, consisting of a 1D wave propagation model for arteries, a 0D model for veins and capillaries, and a one-fiber model for the heart. Additionally, a simulation model coupling EECP with a 1D model was established. Physiological data, including the blood flow in different arteries, were clinically collected from 22 volunteers at rest and in the EECP state. Sensitivity analysis and a simulated annealing algorithm were used to build personalized 0D-1D models using the clinical data in the rest state as optimization objectives. Then, the clinical data on EECP were used to verify the applicability and accuracy of the personalized models.

RESULTS

The simulation results and clinical data were found to be in agreement for all 22 subjects, with waveform similarity coefficients (r) exceeding 90% for most arteries at rest and 80% for most arteries during EECP.

CONCLUSIONS

The 0D-1D closed-loop model and the optimized method can facilitate personalized modeling of the cardiovascular system using the data in the rest state and effectively predict the hemodynamic changes in the EECP state, which is significant for the numerical simulation of personalized hemodynamics. The model can also potentially be used to make decisions regarding patient-specific treatment.

Prevalence and risk factors for vascular calcification based on the ankle-brachial index in the general population: a cross-sectional study

Background

To investigate the prevalence of vascular calcification based on the ankle‐brachial index (ABI) value and analyse the risk factors for vascular calcification in the general population.

Methods

A cross-sectional study was conducted to collect clinical, laboratory, and lifestyle data in individuals aged 30–70 recruited from the physical examination centre. The automatic arteriosclerosis detector was used to measure the ABI. Difference tests, correlation analyses, and multivariate logistic regression analyses were performed to identify risk factors for vascular calcification.

Results

The overall prevalence of vascular calcification was 24.39% in 1033 subjects. The prevalence of vascular calcification in males was much higher than that in females (27.80% vs. 17.49%, P < 0.001). The differences in age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), hypertension, and fatty liver disease were statistically significant in males (P < 0.05). The differences between serum uric acid (UA), total cholesterol (TC), TG, low-density lipoprotein cholesterol (LDL-C), estimated glomerular filtration rate (eGFR), alcohol consumption, exercise, and postmenopausal status were statistically significant in females (P < 0.05). Increased age (odds ratio (OR) = 1.028, 95% confidence interval (CI) 1.008–1.049, P = 0.007), increased BMI (OR = 1.238, 95% CI 1.147–1.337, P < 0.001) and elevated DBP (OR = 2.563, 95% CI 1.262–5.205, P = 0.009) were independent risk factors for vascular calcification in males after adjusting for confounding factors. Increased BMI (OR = 1.159, 95% CI 1.029–1.304, P = 0.015), elevated UA (OR = 1.545, 95% CI 1.077–2.216, P = 0.018), elevated LDL-C (OR = 1.044, 95% CI 1.060–1.027, P < 0.001), and a lack of exercise (OR = 2.402, 95% CI 1.073–5.373, P = 0.033) were independent risk factors for vascular calcification in females.

Conclusions

The prevalence of vascular calcification based on the ABI value is also high in the general population of our centre. Increased age, BMI, and elevated DBP are independent risk factors for vascular calcification in males. Increased BMI, UA, LDL-C, and a lack of exercise are independent risk factors for vascular calcification in females. Attention should be given to strengthening the prevention and control of vascular calcification in the general population.

Ankle-brachial index: more than a diagnostic test?

The ankle-brachial index (ABI) is the relationship between the systolic blood pressure taken at the ankle level and the brachial artery. A pathological ABI (<0.90 or >1.40) indicates the presence of peripheral artery disease (PAD). Many studies indicate the great utility of this test in the diagnosis of PAD due to its ease of use, reproducibility, low cost, and high cost-effectiveness. This evaluation can be directly correlated with cardiovascular morbidity and mortality; however, it has recently been confirmed that a low ABI can be a predictor of major cardiovascular events, as it is related to diabetes mellitus, chronic coronary disease, stroke, and more. The objective of this work was to review the current evidence on the importance of ABI in the diagnosis of PAD and its main role as a predictor of cardiovascular morbidity and mortality.