Incompressible ankle arteries predict increased morbidity and mortality in patients with an elevated ankle brachial index

OBJECTIVES

Patients with an elevated ankle brachial index (ABI) > 1.3 have a high burden of disease and poorer outcome compared to patients with a lower ABI. Previously differences between patients with ABI > 1.3 have not been studied in detail. The aim of this study was to analyze the morbidity and mortality of patients with ABI > 1.3.

METHODS

ABI measurements were performed in the vascular laboratory of Turku university hospital 2011-2013. Patients with ABI>1.3 in at least one lower limb were included in the study and divided into 3 groups: At least one lower limb ABI 1.3-2.5 but both limbs <2.5 (group 1), one limb ABI ≥2.5 (group 2), both limbs ABI ≥ 2.5 (group 3).

RESULTS

534 patients were included in the study. The patients in groups 2 and 3 were more often female (p < .001), older (p < .001), had more diabetes (p = .013), coronary artery disease (p = .001) and chronic heart (p = .010) and kidney failure (p = .013) compared to patients in group 1. The survival of patients in group 2 and 3 was significantly poorer compared to the patients in group 1 (HR1.6, 95% CI 1.2-2.2, p = .002 and 1.7, 95% CI 1.2-2.3, p < .001, respectively). Overall and cardiovascular mortality was higher in groups 2 and 3 than group 1.39.5% of patients with incompressible ankle arteries (ABI ≥ 2.5) in both lower limbs had toe pressure (TP) <50 mmHg and a poorer survival compared to patients with a higher TP.

CONCLUSIONS

Patients with incompressible ankle arteries have significantly higher overall and cardiovascular mortality and a greater burden of disease compared to the patients with a measurable yet abnormally high ABI. TP is a useful diagnostic tool when ABI is immeasurably high. All patients with ABI > 1.3 should be considered as high cardiovascular risk patients.

A nonobstructive condition: Medial arterial calcification

Vascular calcification, including intimal and medial calcification, is closely associated with a significant increase in cardiovascular diseases. Although increased understandings were achieved, people still know much more about intimal calcification than medial calcification because the latter doesn't obstruct the arterial lumen, commonly considered as a non-significant finding. We clarified the pathologic characteristic of medial calcification, its difference from intimal calcification, principally focused on its clinical relevance, such as diagnosis, nosogenesis, and hemodynamics. We underline the importance of identifying and distinguishing medial calcification, understanding its effect to local/systematic arterial compliance, and relationship to diabetic neuropathy. Recent studies emphasize do not ignore its predictive role in cardiovascular mortality. It is of great clinical significance to summarize the mechanisms of occurrence, lesion characteristics, diagnostic methods, pathogenic mechanisms, hemodynamic changes, and the distinction as well as association of intimal calcification with intimal calcification.

Inflammatory, Metabolic, and Coagulation Effects on Medial Arterial Calcification in Patients with Peripheral Arterial Disease

Calcium deposits in the vessel wall in the form of hydroxyapatite can accumulate in the intimal layer, as in atherosclerotic plaque, but also in the medial layer, as in medial arterial calcification (MAC) or medial Möenckeberg sclerosis. Once considered a passive, degenerative process, MAC has recently been shown to be an active process with a complex but tightly regulated pathophysiology. Atherosclerosis and MAC represent distinct clinical entities that correlate in different ways with conventional cardiovascular risk factors. As both entities coexist in the vast majority of patients, it is difficult to estimate the relative contribution of specific risk factors to their development. MAC is strongly associated with age, diabetes mellitus, and chronic kidney disease. Given the complexity of MAC pathophysiology, it is expected that a variety of different factors and signaling pathways may be involved in the development and progression of the disease. In this article, we focus on metabolic factors, primarily hyperphosphatemia and hyperglycemia, and a wide range of possible mechanisms by which they might contribute to the development and progression of MAC. In addition, we provide insight into possible mechanisms by which inflammatory and coagulation factors are involved in vascular calcification processes. A better understanding of the complexity of MAC and the mechanisms involved in its development is essential for the development of potential preventive and therapeutic strategies.

Intracranial Mönckeberg's Atherosclerosis Is Frequently Found in Autopsy Cases of Advanced Stage Malignancy with Cerebral Infarction

Simple Summary

We pathologically compared the cerebral infarction (CI) status in autopsy cases with and without malignancy focusing on the status of intracranial Mönckeberg’s atherosclerosis. Most of Mönckeberg’s atherosclerosis were found in the basal ganglia. Its prevalence in CI cases with malignancy was significantly higher than in malignancy cases without CI and was apparently higher than CI cases without malignancy. The results indicated that Mönckeberg’s atherosclerosis was frequently found in the basal ganglia of CI patients with malignancy and that intracranial Mönckeberg’s atherosclerosis is a potential risk factor for CI in patients with advanced stage malignancy.

Abstract

Cerebral infarction (CI) severely affects the prognosis of patients with malignancy. The aim of the study was to compare the pathology of CI between cases with and without malignancy focusing on intracranial Mönckeberg’s atherosclerosis. Among 778 autopsy cases of craniotomy, 53 cases of “cerebral infarction without malignancy group” (CI group), 50 cases of “malignant tumor without CI group” (MT group), and 39 cases of “cerebral infarction with malignancy group” (CM group) were identified. Mönckeberg’s atherosclerosis was mainly found in the basal ganglia and its prevalence in the CM group (38.5%) was significantly higher than in the MT group (12.0%, p = 0.005), and apparently higher than in the CI group (18.9%, p = 0.057). The CI group was significantly older, had higher BMIs, and a greater prevalence of hypertension and atrial fibrillation compared to the CM group. In addition, the prevalence of chronic renal disease was significantly lower in the CM group (2.6%, p = 0.012) than in the CI group (20.8%). Our results indicated that Mönckeberg’s atherosclerosis was often found in the basal ganglia of CM cases and that intracranial Mönckeberg’s atherosclerosis is a potential risk factor for CI in patients with advanced stage malignancy.

Medial Arterial Calcification: JACC State-of-the-Art Review

Medial arterial calcification (MAC) is a chronic systemic vascular disorder distinct from atherosclerosis that is frequently but not always associated with diabetes mellitus, chronic kidney disease, and aging. MAC is also a part of more complex phenotypes in numerous less common diseases. The hallmarks of MAC include disseminated and progressive precipitation of calcium phosphate within the medial layer, a prolonged and clinically silent course, and compromise of hemodynamics associated with chronic limb-threatening ischemia. MAC increases the risk of complications during vascular interventions and mitigates their outcomes. With the exception of rare monogenetic defects affecting adenosine triphosphate metabolism, MAC pathogenesis remains unknown, and causal therapy is not available. Implementation of genetics and omics-based approaches in research recognizing the critical importance of calcium phosphate thermodynamics holds promise to unravel MAC molecular pathogenesis and to provide guidance for therapy. The current state of knowledge concerning MAC is reviewed, and future perspectives are outlined.

Histopathological characterization of intimal lesions and arterial wall calcification in the arteries of the leg of elderly cadavers

Introduction

Although arteries of the leg have been studied in extensively diseased amputation specimens, little is known about the composition of vascular lesions present in the general population. The aim of this study was to describe the natural development of adaptive intimal thickening, atherosclerotic lesion development and vascular calcification in the leg of a general elderly population.

Materials and Methods

Two hundred and seventy postmortem samples from the popliteal and posterior tibial arteries of 14 elderly cadavers were studied histologically.

Results

Atherosclerotic lesions were more frequently observed in the popliteal (60%) than in the posterior tibial artery (34%; p < .0005). These atherosclerotic plaques were most often nonatheromatous (80% and 83% for popliteal and posterior tibial plaques, respectively). The atheroma's that were present were small (most <25% of plaque area). Atherosclerotic plaque calcification was observed more often in the popliteal (39%) than in the posterior tibial samples (17%; p < .0005). Medial arterial calcification was observed more often in the posterior tibial (62%) than in the popliteal samples (46%; p = .008). Plaque calcification and medial arterial calcification were not associated with lumen stenosis.

Conclusions

In the leg of elderly cadavers, the presence of atherosclerotic plaque and intimal calcification decreases from the proximal popliteal artery to the more distal posterior tibial artery and most atherosclerotic lesions are of the fibrous nonatheromatous type. In contrast, the presence and severity of medial calcification increases from proximal to distal.

Inhibition of tissue-nonspecific alkaline phosphatase protects against medial arterial calcification and improves survival probability in the CKD-MBD mouse model

Medial arterial calcification (MAC) is a major complication of chronic kidney disease (CKD) and an indicator of poor prognosis. Aortic overexpression of tissue-nonspecific alkaline phosphatase (TNAP) accelerates MAC formation. The present study aimed to assess whether a TNAP inhibitor, SBI-425, protects against MAC and improves survival probability in a CKD-mineral and bone disorder (MBD) mouse model. CKD-MBD mice were divided in three groups: vehicle, SBI-10, and SBI-30. They were fed a 0.2% adenine and 0.8% phosphorus diet from 14 to 20 weeks of age to induce CKD, followed by a high-phosphorus (0.2% adenine and 1.8% phosphorus) diet for another 6 weeks. At 14-20 weeks of age, mice in the SBI-10 and SBI-30 groups were given 10 and 30 mg/kg SBI-425 by gavage once a day, respectively, while vehicle-group mice were given distilled water as vehicle. Control mice were fed a standard chow (0.8% phosphorus) between the ages of 8 and 20 weeks. Computed tomography imaging, histology, and aortic tissue calcium content revealed that, compared to vehicle animals, SBI-425 nearly halted the formation of MAC. Mice in the control, SBI-10 and SBI-30 groups exhibited 100% survival, which was significantly better than vehicle-treated mice (57.1%). Aortic mRNA expression of Alpl, encoding TNAP, as well as plasma and aortic tissue TNAP activity, were suppressed by SBI-425 administration, whereas plasma pyrophosphate increased. We conclude that a TNAP inhibitor successfully protected the vasculature from MAC and improved survival rate in a mouse CKD-MBD model, without causing any adverse effects on normal skeletal formation and residual renal function. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Holter ECG findings in diabetics with medial arterial calcification

OBJECTIVES

Medial arterial calcification (MAC) is a nonobstructive condition leading to reduced arterial compliance. The disease most commonly occurs in diabetes mellitus. Decreased ankle-brachial pressure index (ABI) is a well-known marker of increased cardiovascular mortality. However, also the values of ABI above 1.3, typical in MAC, are associated with increased mortality.

METHODS

By means of Holter ECG monitoring, we investigated 41 patients (25 men, 16 women) with mean age of 59±8 years, suffering of type 2 diabetes mellitus and identified as having MAC, and Holter ECG monitoring with an average duration of recording 22.36 hours, was carried out by GE-Marquette MARS ECG Holter system.

RESULTS

We found frequent incidence of cardiac arrhythmias and myocardial ischemia in 22 patients (53.7 %). Only 19 patients (46.3 %) had normal Holter ECG recordings. ABI values were significantly higher in patients with abnormal ECG Holter recordings.

CONCLUSION

Our results confirm the importance of ABI estimation in clinical practice. As the central goal of therapy for patients with myocardial ischemia and/or complex forms of cardiac arrhythmias is the reduction or elimination of these episodes. Ambulatory Holter ECG monitoring plays an important role in the management of these patients (Tab. 7, Ref. 16).

Vascular disease in the lower limb in type 1 diabetes

This review considers peripheral arterial disease (PAD) in the diabetic ischaemic lower limb including both macrovascular and microvascular aspects. The presentation of PAD is probably not significantly different in type 1 compared with type 2 diabetes. PAD in diabetic patients is diffuse and located distally being most severe in the crural and also the foot arteries. It is associated with arterial calcification and occlusion of the arteries rather than stenosis. Compared with the nondiabetic patient, PAD develops at a younger age, and women are equally affected as men. It is not known whether the presentation of ischaemic lower limb disease in diabetes can be explained by one disease, namely, atherosclerosis, which has particular features peculiar to diabetes such as distal arterial involvement, or by the occurrence of two separate diseases: first, classical atherosclerosis and, second, a diabetic macroangiopathy, a term for nonatherosclerotic arterial disease in diabetes that is characterized by medial arterial calcification. Furthermore, there is controversy with regard to the significance of structural changes in the microcirculation of the diabetic foot.

Subjecting the ankle-brachial index to timely scrutiny: is it time to say goodbye to the ABI?

Although the ankle-brachial index (ABI) has been used as an indicator of peripheral artery disease and vascular supply to the foot for over 50 years, it is now associated with reservations and qualifying empirical evidence to the extent that the provocative step of abandoning it totally might be advisable. In this article, the results of three publications concerning the ABI are initially described in some depth and the results from eight additional publications are then summarized more briefly. Cumulatively, the research indicates that ABIs that seem to be normal, as well as those in the subnormal range, are often inflated by medial arterial calcification and can therefore produce a high proportion of false-negative screening test results for arterial disease as well as a misleadingly high impression of vascular sufficiency to the lower extremity. The toe-brachial index is suggested as being likely to overcome the problems associated with the ABI, and other alternatives to the ABI and TBI are acknowledged.

Upper Extremity Medial Arterial Calcification and Peripheral Artery Disease in Asymptomatic Patients With Chronic Kidney Disease in Predialysis Stage

Two types of peripheral artery disease (PAD) in asymptomatic patients with chronic kidney disease (CKD) can be detected by the use of duplex Doppler: medial arterial calcification (MAC) and occlusive PAD. The aim of this pilot study is to evaluate different types of subclinical PAD in upper extremities of patients with CKD. The prevalence of upper extremity MAC and occlusive PAD was investigated in 41 asymptomatic patients with CKD and 18 controls with normal kidney function, using duplex Doppler ultrasound, according to the vascular laboratory protocol. A mild-to-severe MAC was significantly more prevalent in patients with CKD compared to the control group ( P = .015), mostly in radial arteries (RAs; P = .002 and P = .016, respectively). The prevalence of occlusive PAD was not significantly different between the 2 groups ( P = .381). Patients in the CKD group were younger, nonsmokers, and more often had hypertension ( P = .038, P = .038, and P = .034, respectively). A duplex ultrasound screening for upper extremity subclinical PAD in patients with CKD in a predialysis stage may identify patients with mild-to-severe MAC which is important in surgery of hemodialysis access.

Improving major amputation rates in the multicomplex diabetic foot patient: focus on the severity of peripheral arterial disease

OBJECTIVE

Peripheral arterial disease (PAD), as well as diabetic neuropathy, is a risk factor for the development of diabetic foot ulcers. The aim of this study was to evaluate differences and predictors of outcome parameters in patients with diabetic foot by stratifying these subjects according to the severity of PAD.

RESEARCH DESIGN AND METHODS

In a prospective study, patients with new diabetic foot ulcers have been treated and investigated by structured healthcare. Subjects were recruited between 1 January 2000 and 31 December 2007. All study participants underwent a 2-year follow-up observation period. The patients underwent a standardized examination and classification of their foot ulcers according to a modification of the University of Texas Wound Classification System. The severity of PAD was estimated by measurement of the ankle brachial index (ABI) and the continuous wave Doppler flow curve into undisturbed perfusion (0.9 < ABI < 1.3), compensated perfusion (0.5 < ABI < 0.9), decompensated perfusion (ABI < 0.5) and medial arterial calcification.

RESULTS

A total of 678 patients with diabetic foot were consecutively included into the study (69% male, mean age 66.3 ± 11.0 years, mean diabetes duration 15.8 ± 10.2 years). Major amputations (above the ankle) were performed in 4.7% of the patients. 22.1% of these subjects had decompensated PAD. These subjects had delayed ulcer healing, higher risk for major amputation [odds ratio (OR) 7.7, 95% confidence interval (CI) 2.8-21.2, p < 0.001] and mortality (OR 4.9, 95 % CI 1.1-22.1, p < 0.05).

CONCLUSION

This prospective study shows that the severity of PAD significantly influences the outcome of diabetic foot ulcers regarding to wound healing, major amputation and mortality.

A high ankle brachial index is associated with greater left ventricular mass MESA (Multi-Ethnic Study of Atherosclerosis)

OBJECTIVES

This study sought to determine the association of high ankle brachial index (ABI) measurements with left ventricular (LV) mass, and to compare its strength with that of low ABI with LV mass.

BACKGROUND

Arterial stiffness leads to LV mass through nonatherosclerotic pathways in mice. In humans, a high ABI indicates stiff peripheral arteries and is associated with cardiovascular disease (CVD) events. Whether high ABI is associated with LV mass in humans and whether this might reflect consequences of arterial stiffness, atherosclerosis, or both is unknown.

METHODS

Among 4,972 MESA (Multi-Ethnic Study of Atherosclerosis) participants without clinical CVD, we used linear regression to evaluate the association of low (<0.90) and high (>1.40 or incompressible) ABI with LV mass by cardiac magnetic resonance imaging (MRI). Intermediate ABIs served as the reference category. To determine the effect of subclinical atherosclerosis, models were adjusted for common and internal carotid intima media thickness (cIMT) and natural log-transformed coronary artery calcification.

RESULTS

Compared with subjects with intermediate ABI, LV mass was higher with either low (2.70 g/m(2) higher, 95% confidence interval: 0.65 to 4.75) or high ABI (6.84 g/m(2) higher, 95% confidence interval: 3.2 to 10.47) after adjustment for traditional CVD risk factors, kidney function, and C-reactive protein. However, further adjustment for cIMT and CAC substantially attenuated the association of low ABI with LV mass index (1.24 g/m(2) higher, 95% confidence interval: -0.84 to 3.33), whereas the association of high ABI was minimally altered (6.01 g/m(2) higher, 95% confidence interval: 2.36 to 9.67).

CONCLUSIONS

High ABI is associated with greater LV mass; an association that is not attenuated with adjustment for subclinical atherosclerosis in nonperipheral arterial beds. High ABI might lead to greater LV mass through nonatherosclerotic pathways.