Arterial calcification in diabetics

Below-the-Knee Endovascular Revascularization: A Position Statement

Patients with chronic limb-threatening ischemia, the terminal stage of peripheral artery disease, are frequently afflicted by below-the-knee disease. Although all patients should receive guideline-directed medical therapy, restoration of inline flow is oftentimes necessary to avoid limb loss. Proper patient selection and proficiency in endovascular techniques for below-the-knee revascularization are intended to prevent major amputation and promote wound healing. This review, a consensus among an international panel of experienced operators, provides guidance on these challenges from an endovascular perspective and offers techniques to navigate this complex disease process.

Monckeberg's Medial Sclerosis as a Cause for Headache and Facial Pain

PURPOSE OF REVIEW

Mönckeberg's medial sclerosis (MMS) is a chronic, non-inflammatory degenerative condition affecting primarily the tunica media of muscular arteries resulting in their calcification. The purpose of this comprehensive review is to describe MMS as it appears in the literature, in the context of headache and facial pain. Understanding the etiopathology, the associated conditions, and the differential diagnoses is important in managing MMS.

RECENT FINDINGS

Management of MMS primarily depends upon identification of its associated conditions and their treatment. Due to the rare incidence and inadequate literature on MMS presenting with headaches, the diagnosis of the pain and the entity itself is challenging. MMS is characterized by associated systemic conditions and absence of inflammatory markers. It can mimic giant cell arteritis (GCA) and other pain entities. An interdisciplinary approach involving appropriate specialties is recommended.

Breast arterial calcifications: a systematic review and meta-analysis of their determinants and their association with cardiovascular events

OBJECTIVE

Breast arterial calcifications (BAC), regularly observed at mammography, are medial calcifications and as such an expression of arteriosclerosis. Our objective was to evaluate and summarize the available evidence on the associations of BAC with cardiovascular risk factors and cardiovascular risk.

METHODS

A systematic literature review and meta-analysis were conducted. Embase and PubMed databases were searched. After critical appraisal, odds ratios were extracted from studies of moderate or good quality that examined risk factors for BAC or associations of BAC with cardiovascular disease. Random effects model meta-analyses were used to calculate pooled odds ratios and 95% confidence intervals (95%CIs).

RESULTS

BAC prevalence is around 12.7% among women in breast cancer screening programs. Increasing age (pooled OR 2.98 [95%CI 2.31-3.85] for every 10 years), diabetes (pooled OR: 1.88 [95%CI 1.36-2.59]) and parity as opposed to nulliparity (pooled OR 3.43 [95%CI 2.23-5.27]) are associated with higher BAC prevalence. Smoking is associated with lower BAC prevalence (pooled OR 0.48 [95%CI 0.39-0.60]). No associations were found with hypertension, obesity or dyslipidemia. Although longitudinal studies (n = 3) were scarce, BAC appear to be associated with an increased risk of cardiovascular disease events (adjusted hazard ratios for coronary heart disease ranging from 1.32 [95%CI 1.08-1.60] to 1.44 [95%CI1.02-2.05]).

CONCLUSION

BAC appear to be associated with an increased risk of cardiovascular disease events, while only being associated with some of the known cardiovascular risk factors, illustrating that medial arterial calcification might contribute to cardiovascular disease through a pathway distinct from the intimal atherosclerotic process.

Pooled analysis of the CONFIRM registries: safety outcomes in diabetic patients treated with orbital atherectomy for peripheral artery disease

PURPOSE

To compare the acute outcomes of orbital atherectomy treatment in diabetic vs. non-diabetic patients with peripheral artery disease (PAD).

METHODS

The CONFIRM registry series contained 1842 diabetic patients (1111 men; mean age 70.6±10.2 years) with 2819 lesions and 1247 non-diabetic patients (732 men; mean age 72.9±10.7 years) with 1885 lesions. The composite rate of procedure-related complications, including dissection, perforation, slow flow, vessel closure, spasm, embolism, and thrombus formation, was analyzed for the diabetic and non-diabetic groups.

RESULTS

Diabetics were younger but had a higher prevalence of coronary artery disease (p<0.001), renal disease (p<0.001), hypertension (p<0.001), hyperlipidemia (p<0.001), and lower ankle-brachial index scores (p=0.007). Diabetics had more severe PAD (Rutherford category 4-6; p<0.001), longer lesions (p<0.001), more infrapopliteal lesions (58% vs. 46%, p<0.001), and more lesions with severe and moderate calcium (86% vs. 78%, p<0.001). Diabetic and non-diabetic patients had the same (21.8%) composite rate of procedure-related complications, as well as similar rates of dissection (11.4% vs. 10.8%, p=0.68), embolism (2.2% vs. 2.4%, p=0.67), and thrombus formation (1.3% vs. 1.1%, p=0.75). However, diabetics had lower rates of perforation (0.5% vs. 1.1%, p=0.03) and spasm (5.5% vs. 7.6%, p=0.005), but a higher rate of slow flow (5.0% vs. 3.5%, p=0.02) and a tendency toward increased vessel closure (1.7% vs. 0.9%, p=0.06).

CONCLUSION

Plaque modification with orbital atherectomy resulted in similar low procedure-related complication rates in both the diabetic and non-diabetic groups, despite diabetics having more unfavorable baseline clinical and lesion characteristics. This study suggests that orbital atherectomy is a safe and effective treatment modality in both the diabetic and the non-diabetic populations.

Impact of diabetes mellitus on characteristics of carotid plaques and outcomes after carotid endarterectomy

BACKGROUND

Published results for carotid endarterectomy (CEA) in symptomatic and asymptomatic severe carotid stenosis with diabetes mellitus (DM) are contradictory. To evaluate perioperative and long-term results of CEA in patients with DM, we retrospectively analyzed data of patients with or without DM who underwent CEA in our institute.

METHODS

Between January 2005 and December 2010, 281 consecutive CEAs were performed in 268 patients under general anesthesia. All patients were subject to cardiac work-ups before surgery, and coronary revascularization was performed prior to CEA if patients were diagnosed with significant coronary artery stenosis. Lesion characteristics were assessed by a duplex ultrasound scan, computed tomography angiography (CTA), and plaque imaging on magnetic resonance imaging (MRI) before surgery, and patients were followed-up by a duplex ultrasound scan at three, six, and 12 months, then yearly, after surgery.

RESULTS

Of 281 cases, 136 had DM (48 %). Diabetic patients more frequently had a history of coronary artery disease than non-diabetic patients (48.5 % vs. 36.6 %, P = 0.042). Coronary intervention prior to CEA was more frequently performed in diabetic patients than in non-diabetic patients (22.1 % vs. 11.0 %, P = 0.013). The incidence of perioperative (30 day) stroke (P = 1.000), death (P = 1.000), and cardiac complications (P = 0.484) did not differ among groups. Follow-up was available in 77.2 % of patients, with a median duration of 50 months (interquartile range, 32.1-67.2 months). The incidence of ipsilateral stroke (P = 0.720), death (P = 0.351), and severe restenosis (peak systolic velocity > 230 cm/sec) (P = 0.905) were not different between groups.

CONCLUSIONS

DM does not increase the risk of perioperative complications and does not influence long-term outcomes after CEA if preexisting vascular risk factors and cardiac diseases are appropriately evaluated and treated before surgery.

Mechanisms and clinical consequences of vascular calcification

Vascular calcification has severe clinical consequences and is considered an accurate predictor of future adverse cardiovascular events, including myocardial infarction and stroke. Previously vascular calcification was thought to be a passive process which involved the deposition of calcium and phosphate in arteries and cardiac valves. However, recent studies have shown that vascular calcification is a highly regulated, cell-mediated process similar to bone formation. In this article, we outline the current understanding of key mechanisms governing vascular calcification and highlight the clinical consequences. By understanding better the molecular pathways and genetic circuitry responsible for the pathological mineralization process novel drug targets may be identified and exploited to combat and reduce the detrimental effects of vascular calcification on human health.

Arterial calcification increases in distal arteries in patients with peripheral arterial disease

The aim of this study was to determine if significant differences in plaque composition exist between the popliteal and tibial vessels in patients with severe peripheral arterial disease (PAD). Forty-four patients with PAD required either above-knee (n = 38), below-knee (n = 5), or through-knee (n = 1) amputation for pedal sepsis/gangrene. The 51 vessels (anterior tibial, n = 9; posterior tibial, n = 10; peroneal, n = 3; popliteal, n = 29) were obtained and underwent intravascular ultrasound (IVUS) evaluation ex vivo within 24 hr of amputation. Sequential IVUS data were obtained at known intervals throughout the vessel length and then analyzed with radiofrequency techniques for quantification of plaque composition, plaque volume, and total vessel volume. Plaque composition was categorized as fibrous, fibro-fatty, necrotic core, and dense calcium. Clinical data were obtained via review of electronic records at the time of amputation. Two-sided t-tests were performed to compare components within each plaque. Results are expressed as mean percentage +/- standard error of the mean. Tibial vessels had more dense calcium within these plaques than popliteal arteries (33.8 +/- 5.6% vs. 10.6 +/- 1.9%, p < 0.001). Consequently, distal vessels had less fibro-fatty and fibrous plaque than popliteal arteries (7.7 +/- 1.4% vs. 13.1 +/- 1.2%, p < 0.005; 42.4 +/- 4.7% vs. 61.4 +/- 2.2%, p < 0.001, respectively). Necrotic core plaque composition was found to be similar when comparing tibial versus popliteal arteries (16.1% vs. 14.9%, p = nonsignificant). Clinical factors including diabetes, hyperlipidemia, and chronic renal insufficiency were not associated with plaque composition differences using a univariate analysis. As we progress distally in the arterial tree of patients with PAD, calcium plaque content increases with decreasing burden of fibro-fatty plaque. Clinical and demographic factors, with the exception of smoking, were not found to be associated with atherosclerotic plaque composition.

Vascular calcification: mechanisms and clinical ramifications

Vascular calcification, long thought to result from passive degeneration, involves a complex, regulated process of biomineralization resembling osteogenesis. Evidence indicates that proteins controlling bone mineralization are also involved in the regulation of vascular calcification. Artery wall cells grown in culture are induced to become osteogenic by inflammatory and atherogenic stimuli. Furthermore, osteoclast-like cells are found in calcified atherosclerotic plaques, and active resorption of ectopic vascular calcification has been demonstrated. In general, soft tissue calcification arises in areas of chronic inflammation, possibly functioning as a barrier limiting the spread of the inflammatory stimulus. Atherosclerotic calcification may be one example of this process, in which oxidized lipids are the inflammatory stimulus. Calcification is widely used as a clinical indicator of atherosclerosis. It progresses nonlinearly with time, following a sigmoid-shaped curve. The relationship between calcification and clinical events likely relates to mechanical instability introduced by calcified plaque at its interface with softer, noncalcified plaque. In general, as calcification proceeds, interface surface area increases initially, but eventually decreases as plaques coalesce. This phenomenon may account for reports of less calcification in unstable plaque. Vascular calcification is exacerbated in certain clinical entities, including diabetes, menopause, and osteoporosis. Mechanisms linking them must be considered in clinical decisions. For example, treatments for osteoporosis may have unanticipated effects on vascular calcification; the converse also applies. Further understanding of processes governing vascular calcification may yield new therapeutic options for vascular disease.

Impact of diabetes on coronary stenosis and coronary artery calcification detected by electron-beam computed tomography in symptomatic patients

OBJECTIVE

Ischemic heart disease is a pivotal complication for diabetic patients. Electron-beam computed tomography (EBCT) represents the only noninvasive method that allows for accurate quantification of coronary artery calcification that reflects underlying atherosclerotic disease. Although coronary calcium score (CCS) cut points that predict the presence of angiographic stenosis have been established in nondiabetic individuals, it is not known whether coronary calcifications in diabetic patients are associated with the presence of significant coronary stenoses. In this study, we evaluated the relationship between coronary calcifications and angiographic stenosis in symptomatic patients with or without type 2 diabetes.

RESEARCH DESIGN AND METHODS

In this study, 282 patients (204 men and 78 women) with chest pain, including 101 diabetic patients and 181 nondiabetic patients (mean age 63 +/- 9.6 years), underwent coronary angiography and EBCT with determination of CCS using Agatston's method. Luminal stenosis >or= 50% was defined as significant coronary stenosis.

RESULTS

Angiography identified 205 patients with significant stenoses (89 of 101 diabetic patients, 114 of 181 nondiabetic patients). The sensitivity and specificity of EBCT to detect significant coronary stenosis were not significantly different between diabetic and nondiabetic patients. In diabetic patients, a CCS >or=90 was associated with 75% sensitivity and 75% specificity, whereas a CCS >or=200 was associated with 64% sensitivity and 83% specificity.

CONCLUSIONS

We demonstrated that calcification of the coronary arteries in symptomatic diabetic patients is well associated with severity of coronary stenosis, as in nondiabetic patients.

Lack of association of lipoprotein(a) levels with coronary calcium deposits in asymptomatic postmenopausal women

OBJECTIVES

This study sought to determine the relationship of lipoprotein(a) (Lp(a)) and other cardiac risk factors to coronary atherosclerosis as measured by calcification of coronary arteries in asymptomatic postmenopausal women.

BACKGROUND

Lipoprotein(a) is considered a risk factor for coronary heart disease. Coronary calcium deposition is believed to be a useful noninvasive marker of coronary atherosclerosis in women. However, to our knowledge, there are no reports of the relationship of Lp(a) to coronary calcium in postmenopausal women.

METHODS

In 178 asymptomatic postmenopausal women (64 +/- 8 years), we measured Lp(a) and other cardiac risk factors: age, hypertension, diabetes, low-density lipoprotein cholesterol, smoking status, body mass index, physical activity level and duration of hormone replacement therapy. Electron-beam computed tomography was done to measure coronary calcium (calcium score). We analyzed the relationship between calcium score and cardiac risk factors using multivariate analysis.

RESULTS

Although calcium score correlated with traditional risk factors of age, diabetes, hypertension and smoking, it did not correlate with Lp(a) in the asymptomatic postmenopausal women. Similar multivariate analyses were done in the subjects age >60 years and in the subjects with significant coronary calcium deposit (calcium score > or =50). These analyses also have failed to show an association of levels of Lp(a) with coronary calcium deposits.

CONCLUSIONS

We conclude that in asymptomatic postmenopausal women, Lp(a) levels do not correlate with coronary atherosclerosis as measured by coronary calcium deposits.

Extracoronary atherosclerotic plaque at multiple sites and total coronary calcification deposit in asymptomatic men. Association with coronary risk profile

BACKGROUND

Recent studies have suggested that knowledge of the extent of subclinical atherosclerosis may improve prognostic information in subjects at risk of cardiovascular disease. Therefore, we tested the value of extracoronary plaque detected with echography at multiple sites and that of total coronary calcification deposit evaluated with ultrafast computed tomography for predicting the risk of coronary events estimated on the basis of traditional risk factors.

METHODS AND RESULTS

We analyzed in 618 asymptomatic at-risk men the extent of extracoronary atherosclerosis, as assessed with ultrasound imaging of carotid, aortic, and femoral sites and coded as number of disease sites (none, one, two, or three) on the basis of the presence of plaque at each site, and the amount of total coronary calcification deposit, as evaluated with ultrafast computed tomography and coded as grade 0, 1, 2, or 3 on the basis of the determination of a total coronary calcium score. Concomitantly, age, systolic pressure, total and HDL cholesterol levels, current smoking, presence of diabetes, and presence of ECG left ventricular hypertrophy (ECG-LVH) were evaluated with the goal of estimating coronary risk with the use of the Framingham Study risk algorithm. The prevalence rates of at least one extracoronary disease site and coronary calcification (any grade) were high (72% and 63%). There was a strong association between the number of extracoronary disease sites and the grade of coronary calcification (P < .001). As the number of extracoronary disease sites increased, age, systolic pressure, smoking frequency, and number of risk factors increased (P < .001). As the grade of coronary calcification increased, age and systolic pressure increased (P < .001), as did the number of risk factors (P < .01). The estimated coronary risk increased with the number of extracoronary disease sites and the grade of coronary calcification (P < .001). The odds ratio of coronary risk between three and no extracoronary disease site was 2.37 (95% confidence interval [CI], 1.08 to 5.21), whereas that between grade 3 and grade 0 of coronary calcification was 1.79 (95% CI, 0.94 to 3.40).

CONCLUSIONS

In an apparently healthy population, the extracoronary atherosclerotic burden as measured with multiple-site echography appears to be more powerful than the ultrafast computed tomography-detected coronary calcium burden in reflecting the multifactorial coronary risk profile. However, only men were included in the present study, and the present findings cannot be extrapolated to women.

Coronary calcium and atherosclerosis by ultrafast computed tomography in asymptomatic men and women: relation to age and risk factors

We evaluated 675 men and 190 women who had no symptoms or history of clinical CHD, to determine the prevalence and risk factor correlates of CAC deposits as a marker of atherosclerosis. Measurements were taken noninvasively by ultrafast CT. The presence and extent of CAC deposits as measured by ultrafast CT was determined in all subjects, who also received personal and family medical history and risk factor questionnaire. The prevalence of CAC deposits increased significantly with age, ranging from 15% and 30% in men and women, respectively, < 40 years of age to 93% and 75% in those aged > or = 70 years. Prevalence and total score also increased by the number of risk factors present, although in those aged > 60 years a high prevalence (> 80% in men) of calcium was present regardless of the presence of risk factors. In multiple logistic regression, age, male gender, hypertension, diabetes, hypercholesterolemia, and obesity were independently associated with CAC deposits. These results suggest a high prevalence of atherosclerosis with increasing age and the presence of risk factors in men and women who have no symptoms. Studies to determine the prognostic value of CAC in individuals with no symptoms are needed to determine which populations may benefit most from CAC deposit screening.

Risk factor correlates of coronary calcium as evaluated by ultrafast computed tomography

Coronary artery calcium is invariably associated with atherosclerosis and has been linked to an increased risk of coronary events. Ultrafast computed tomography (CT) was recently used to document the presence and relative quantity of coronary calcium. The use of the self-reported coronary risk factors to identify persons with coronary calcium as documented by ultrafast CT screening was examined in 458 men and 139 women aged 26 to 81 years (88% asymptomatic). All subjects underwent ultrafast CT scanning, and received a questionnaire and underwent an interview regarding medical and risk factor history. Total calcium score was calculated as the sum of lesion-specific scores, each calculated as the product of density > or = 130 Hounsfield units and area > or = 0.51 mm2. The prevalence of coronary calcium increased significantly (p < 0.01) by age group, and the greater the number of risk factors present, the greater the likelihood of calcium. From multiple logistic regression, age (p < 0.01), male sex (relative risk [RR] 3.03; p < 0.01), and history of smoking (RR 1.85; p < 0.01) and hypertension (RR 1.65; p < 0.05) were independently associated with the probability of detectable calcium. Among asymptomatic subjects, an association with hypercholesterolemia was also seen (RR 1.56; p < 0.05). The results demonstrate that cardiovascular risk factors can help in identifying the likelihood of coronary calcium.

Evaluation of a computerised test for the assessment of peripheral vascular disease

This paper reports a study carried out in 200 patients to assess the effectiveness of a clinical vascular laboratory in the routine assessment of peripheral vascular disease (PVD) of the lower limb. Laboratory assessments involved a computer based hierarchical testing system incorporating pedal pressure indices, maximum walking distances and principal component analysis of the common femoral artery blood velocity waveform. The study fell into two parts. In the first, the laboratory assessments of 100 patients referred six years ago were compared retrospectively with their eventual clinical outcome. In this comparison, the laboratory provided a "diagnosis" which was 79% correct. In the second, a double blind prospective study was carried out in 100 patients to compare the vascular laboratory "diagnosis" with the diagnosis and prognosis of a skilled clinician, the outcome being compared one year after the initial assessment. In this study the laboratory proved to be correct in 78% of cases, the clinician in 70%. With a slightly modified computer protocol for the non vascular diagnosis, the computer would have been correct in 85% of cases. This test provides a quantitative and objective assessment of PVD which can assist in the patient's clinical diagnosis and management.