Reply to Arterial Stiffness in Patients With Peripheral Arterial Disease

Factors Associated to Arterial Stiffness in Patients With Symptomatic Peripheral Artery Disease

BACKGROUND

The aim of this study was to identify the clinical factors associated with arterial stiffness in patients with symptomatic peripheral artery disease.

METHODS

In this cross-sectional study, 181 patients (67% men; mean aged 66 ± 9 years) were recruited and had their central arterial stiffness assessed by carotid-femoral pulse wave velocity (cf-PWV). Clinical characteristics are sociodemographic data, body mass index, comorbid conditions, and walking capacity.

RESULTS

Multiple linear regression analysis showed that age (b = 0.182, P = 0.032), body mass index (b = 0.254, P = 0.002), and mean blood pressure (b = 0.249, P = 0.021) were positively associated with cf-PWV.

CONCLUSIONS

Our results showed that the aging, elevated body mass index, and higher blood pressure are clinical factors associated with increased arterial stiffness in patients with peripheral artery disease.

Cardiac Autonomic Modulation Is Associated with Arterial Stiffness in Patients with Symptomatic Peripheral Artery Disease

BACKGROUND

The objective of this study was to analyze the association between cardiac autonomic modulation and arterial stiffness in patients with peripheral artery disease (PAD).

METHODS

This cross-sectional study included one hundred fourteen patients with symptomatic PAD (67.5% men; 65 ± 7 years; body mass index: 26.8 ± 4.5 kg/m²). Heart rate variability (HRV) was measured within time (standard deviation of all RR intervals [beat to beat heart interval] [SDNN], root mean square of the successive differences between adjacent normal RR intervals [RMSSD], and the proportion of successive RR intervals that differed by more than 50 msec [pNN50]) and frequency (low frequency [LF] and high frequency [HF]) domains. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV). Crude and adjusted linear regression analyses examined the relationship between HRV and cfPWV.

RESULTS

Nonsignificant crude associations were identified among cfPWV and RMSSD (P = 0.181), SDNN (P = 0.105), pNN50 (P = 0.087), LF (P = 0.376), HF (P = 0.175), and LF/HF ratio (P = 0.426). After adjustments for age, sex, smoking, body mass index, ankle-brachial index, and use of beta-blockers, significant associations were identified among cfPWV and RMSSD (P = 0.037), SDNN (P = 0.049), and pNN50 (P = 0.049).

CONCLUSIONS

Cardiac autonomic modulation was significantly associated with arterial stiffness in patients with PAD after adjustment for confounding factors. This relationship may contribute to the enhanced cardiovascular disease risk for PAD patients and provides a target for strategies to improve patient clinical outcomes.

Diabetic cardiomyopathy: prevalence, determinants and potential treatments

The prevalence of type 2 diabetes (T2D) has reached a pandemic scale. These patients are at a substantially elevated risk of developing cardiovascular disease, with heart failure (HF) being a leading cause of morbidity and mortality. Even in the absence of traditional risk factors, diabetes still confers up to a twofold increased risk of developing HF. This has led to identifying diabetes as an independent risk factor for HF and recognition of the distinct clinical entity, diabetic cardiomyopathy. Despite a wealth of research interest, the prevalence and determinants of diabetic cardiomyopathy remain uncertain. This limited understanding of the pathophysiology of diabetic heart disease has also hindered development of effective treatments. Tight blood-glucose and blood-pressure control have not convincingly been shown to reduce macrovascular outcomes in T2D. There is, however, emerging evidence that T2D is reversible and that the metabolic abnormalities can be reversed with weight loss. Increased aerobic exercise capacity is associated with significantly lower cardiovascular and overall mortality in diabetes. Whether such lifestyle modifications as weight loss and exercise may ameliorate the structural and functional derangements of the diabetic heart has yet to be established. In this review, the link between T2D and myocardial dysfunction is explored. Insights into the structural and functional perturbations that typify the diabetic heart are first described. This is followed by an examination of the pathophysiological mechanisms that contribute to the development of cardiovascular disease in T2D. Lastly, the current and emerging therapeutic strategies to prevent or ameliorate cardiac dysfunction in T2D are evaluated.

Oxidative Stress and Arterial Dysfunction in Peripheral Artery Disease

Peripheral artery disease (PAD) is an atherosclerotic disease characterized by a narrowing of the arteries in the lower extremities. Disease manifestations are the result of more than just reduced blood flow, and include endothelial dysfunction, arterial stiffness, and inflammation. Growing evidence suggests that these factors lead to functional impairment and decline in PAD patients. Oxidative stress also plays an important role in the disease, and a growing amount of data suggest a link between arterial dysfunction and oxidative stress. In this review, we present the current evidence for the involvement of endothelial dysfunction, arterial stiffness, and inflammation in the pathophysiology of PAD. We also discuss the links between these factors and oxidative stress, with a focus on nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2)-derived reactive oxygen species (ROS) and decreased nitric oxide (NO) bioavailability. Finally, the potential therapeutic role of NOX2 antioxidants for improving arterial function and functional status in PAD patients is explored.

Peripheral vascular disease assessment in the lower limb: a review of current and emerging non-invasive diagnostic methods

BACKGROUND

Worldwide, at least 200 million people are affected by peripheral vascular diseases (PVDs), including peripheral arterial disease (PAD), chronic venous insufficiency (CVI) and deep vein thrombosis (DVT). The high prevalence and serious consequences of PVDs have led to the development of several diagnostic tools and clinical guidelines to assist timely diagnosis and patient management. Given the increasing number of diagnostic methods available, a comprehensive review of available technologies is timely in order to understand their limitations and direct future development effort.

MAIN BODY

This paper reviews the available diagnostic methods for PAD, CVI, and DVT with a focus on non-invasive modalities. Each method is critically evaluated in terms of sensitivity, specificity, accuracy, ease of use, procedure time duration, and training requirements where applicable.

CONCLUSION

This review emphasizes the limitations of existing methods, highlighting a latent need for the development of new non-invasive, efficient diagnostic methods. Some newly emerging technologies are identified, in particular wearable sensors, which demonstrate considerable potential to address the need for simple, cost-effective, accurate and timely diagnosis of PVDs.

Arterial stiffness and subendocardial viability ratio in patients with peripheral arterial disease

Arterial stiffening is a hallmark of the aging process and atherosclerosis, including peripheral arterial disease (PAD). We investigated the associations between carotid-femoral pulse wave velocity (c-fPWV), augmentation index corrected for heart rate (Aix@HR75), ankle brachial index (ABI), and subendocardial viability ratio (SEVR), an indicator of cardiac perfusion. The c-fPWV, Aix@HR75, and SEVR was estimated using applanation tonometry. The ankle systolic pressure measurements for the calculation of the ABI were obtained using an 8-mHz Doppler probe. The study group included 555 subjects, mean age 63 ± 11 years (248 PAD (ABI < 1.0), and 307 non-PAD (ABI ≥ 1.0 ≤ 1.3). After the stepwise selection process in both PAD and non-PAD patients SEVR was not related to c-fPWV and ABI (P = .154; P = .156) and (P = .101; P = .402), respectively. In PAD patients, SEVR was negatively related to Aix@HR75 (P < .0001) and aortic PP (P = .0005). In conclusion, arterial stiffness is associated with non-invasive indices of myocardial perfusion in PAD patients, suggesting a potential pathophysiological link for increased cardiovascular events.

Upper Extremity Pulse Pressure Predicts Amputation-Free Survival after Lower Extremity Bypass

Increased pulse pressure reflects pathologic arterial stiffening and predicts cardiovascular events and mortality. The effect of pulse pressure on outcomes in lower extremity bypass patients remains unknown. We thus investigated whether preoperative pulse pressure could predict amputation-free survival in patients undergoing lower extremity bypass for atherosclerotic occlusive disease. An institutional database identified 240 included patients undergoing lower extremity bypass from 2005 to 2014. Preoperative demographics, cardiovascular risk factors, operative factors, and systolic and diastolic blood pressures were recorded, and compared between patients with pulse pressures above and below 80 mm Hg. Factors were analyzed in bi- and multivariable models to assess independent predictors of amputation-free survival. Kaplan-Meier analysis was performed to evaluate the temporal effect of pulse pressure ≥80 mm Hg on amputation-free survival. Patients with a pulse pressure ≥80 mm Hg were older, male, and had higher systolic and lower diastolic pressures. Patients with pulse pressure <80 mm Hg demonstrated a survival advantage on Kaplan-Meier analysis at six months (log-rank P = 0.003) and one year (P = 0.005) postoperatively. In multivariable analysis, independent risk factors for decreased amputation-free survival at six months included nonwhite race, tissue loss, infrapopliteal target, and preoperative pulse pressure ≥80 mm Hg (hazard ratio 2.60; P = 0.02), while only tissue loss and pulse pressure ≥80 mm Hg (hazard ratio 2.30, P = 0.02) remained predictive at one year. Increased pulse pressure is independently associated with decreased amputation-free survival in patients undergoing lower extremity bypass. Further efforts to understand the relationship between increased arterial stiffness and poor outcomes in these patients are needed.

Prevalence of peripheral vascular disease and its association with carotid intima-media thickness and arterial stiffness in type 2 diabetes: the Chennai urban rural epidemiology study (CURES 111)

We investigated the prevalence of peripheral vascular disease (PVD) and its association with preclinical atherosclerotic markers [intima-media thickness (IMT)] and arterial stiffness among 1755 urban south Indian type 2 diabetic subjects recruited from the Chennai Urban Rural Epidemiology Study (CURES). Doppler studies were performed, and PVD was defined as ankle-brachial index (ABI) of ≤0.9. IMT of the common carotid artery was determined using high-resolution B-mode ultrasonography, and augmentation index (AGI) was measured using the Sphygmocor apparatus. The overall prevalence of PVD was 8.3% (age-standardized 6.5%). The prevalence of PVD was higher among known diabetic subjects (n = 1401) compared to newly detected diabetic subjects (n = 354) (8.6% vs 6.8%, p = 0.250). The mean IMT and AGI in subjects with PVD were significantly higher compared to subjects without PVD (IMT: 0.99 ± 0.26 mm vs 0.83 ± 0.19 mm; AGI: 28.1 ± 9.6% vs 25.7 ± 9.8%, respectively). IMT was independently associated with PVD even after adjusting for age [odds ratio (OR) = 2.9 (1.2-6.7), p = 0.016 for second tertile and OR = 3.9 (1.7-9.3), p = 0.002 for third tertile compared to first tertile]. AGI was also associated with PVD in the unadjusted model [OR = 1.8 (1.1-3.1), p = 0.027 for second tertile compared to first tertile]. However, when adjusted for age, the significance was lost. In conclusion, among urban south Indian type 2 diabetic subjects, the prevalence of PVD is 8.3% and IMT is more strongly associated with PVD than AGI.

Physiological correlates of beat-to-beat, ambulatory, and day-to-day home blood pressure variability after transient ischemic attack or minor stroke

BACKGROUND AND PURPOSE

Visit-to-visit and day-to-day variability in systolic blood pressure (SBP) are associated with an increased risk of stroke, more strongly than variability on 24-hour ambulatory BP monitoring, but underlying physiological mechanisms are unclear. We related potentially relevant physiological characteristics to beat-to-beat, ambulatory, and day-to-day BP variability to identify underlying mechanisms and potential therapeutic targets.

METHODS

BP variability (coefficient of variation [CV]) on 1-month home BP monitoring (3 sitting readings, 3× daily), on 24-hour ambulatory BP monitoring, and on 5-minute beat-to-beat monitoring was related to BP reactivity (to mental arithmetic), arterial aging (aortic stiffness: carotid-femoral pulse wave velocity; aortic pulsatility), heart rate variability (CV of normal-to-normal R-R interval), and orthostatic responses.

RESULTS

In 223 patients within 6 weeks of a transient ischemic attack or minor stroke, beat-to-beat and home SBP-CVs were associated with response to arithmetic (beat-to-beat odds ratio per SD=1.64; P<0.0001 and home BP monitoring, 1.41; P=0.025), aortic stiffness (1.84; P<0.0001 and 1.31; P=0.04), aortic pulsatility (1.98; P<0.0001 and 1.61; P<0.0001), and heart rate variability-CV of normal-to-normal R-R interval (1.34; P=0.03 and 1.35; P=0.03), independently of age, sex, and aortic BP. Orthostatic BP changes were associated only with SBP-CV on home BP monitoring (0.62; P=0.002). In contrast, no physiological measures were associated with within-day BP variability on awake ambulatory BP monitoring except response to mental arithmetic (1.40; P=0.01).

CONCLUSIONS

Beat-to-beat and day-to-day SBP variability, but not variability on ambulatory BP monitoring, had similar physiological correlates, suggesting common underlying mechanisms and identifying potentially treatable targets that may be responsible for the relationship between SBP variability and stroke risk.