Patients with Polyvascular Disease: A Very High-risk Group

Polyvascular disease (PolyvascDis) with atherosclerosis occurring in >2 vascular beds (coronary, carotid, aortic, visceral and/or peripheral arteries) is encountered in 15-30% of patients who experience greater rates of major adverse cardiovascular (CV) events. Every patient with multiple CV risk factors or presenting with CV disease in one arterial bed should be assessed for PolyvascDis clinically and noninvasively prior to invasive angiography. Peripheral arterial disease (PAD) can be readily diagnosed in routine practice by measuring the ankle-brachial index. Carotid disease can be diagnosed by duplex ultrasound showing % stenosis and/or presence of plaques. Coronary artery disease (CAD) can be screened by determining coronary artery calcium score using coronary computed tomography angiography; further, non-invasive testing includes exercise stress and/or myocardial perfusion imaging or dobutamine stress test, prior to coronary angiography. Abdominal ultrasound can reveal an abdominal aortic aneurysm. Computed tomography angiography will be needed in patients with suspected mesenteric ischemia to assess the mesenteric arteries. Patients with the acute coronary syndrome and concomitant other arterial diseases have more extensive CAD and poorer CV outcomes. Similarly, PolyvascDis in patients with carotid disease and/or other PAD is independently associated with an increased risk for all-cause and CV mortality during long-term follow-up. Treatment of patients with PolyvascDis should include aggressive management of all modifiable risk factors by lifestyle changes and drug therapy, with particular attention to patients who are commonly undertreated, such as those with PAD. Revascularization should be reserved for symptomatic vascular beds, using the least aggressive strategy in a multidisciplinary vascular team approach.

Auscultation System for Acquisition of Vascular Sounds - Towards Sound-Based Monitoring of the Carotid Artery

Introduction

Atherosclerotic diseases of the carotid are a primary cause of cerebrovascular events such as stroke. For the diagnosis and monitoring angiography, ultrasound- or magnetic resonance-based imaging is used which requires costly hardware. In contrast, the auscultation of carotid sounds and screening for bruits - audible patterns related to turbulent blood flow - is a simple examination with comparably little technical demands. It can indicate atherosclerotic diseases and justify further diagnostics but is currently subjective and examiner dependent.

Methods

We propose an easy-to-use computer-assisted auscultation system for a stable and reproducible acquisition of vascular sounds of the carotid. A dedicated skin-transducer-interface was incorporated into a handheld device. The interface comprises two bell-shaped structures, one with additional acoustic membrane, to ensure defined skin contact and a stable propagation path of the sound. The device is connected wirelessly to a desktop application allowing real-time visualization, assessment of signal quality and input of supplementary information along with storage of recordings in a database. An experimental study with 5 healthy subjects was conducted to evaluate usability and stability of the device. Five recordings per carotid served as data basis for a wavelet-based analysis of the stability of spectral characteristics of the recordings.

Results

The energy distribution of the wavelet-based stationary spectra proved stable for measurements of a particular carotid with the majority of the energy located between 3 and 40 Hz. Different spectral properties of the carotids of one individual indicate the presence of sound characteristics linked to the particular vessel. User-dependent parameters such as variations of the applied contact pressure appeared to have minor influence on the general stability.

Conclusion

The system provides a platform for reproducible carotid auscultation and the creation of a database of pathological vascular sounds, which is a prerequisite to investigate sound-based vascular monitoring.

Diabetes and carotid artery disease: a narrative review

Diabetes mellitus (DM) has been linked to an increased prevalence and severity of carotid artery disease, as well as polyvascular disease. Carotid disease is also associated with obesity and abnormal peri-organ and intra-organ fat (APIFat) deposition (i.e., excess fat accumulation in several organs such as the liver, heart and vessels). In turn, DM is associated with APIFat. The coexistence of these comorbidities confers a greater risk of vascular events. Clinicians should also consider that carotid bruits may predict cardiovascular risk. DM has been related to a greater risk of adverse outcomes after carotid endarterectomy or stenting. Whether modifying risk factors (e.g., glycaemia and dyslipidaemia) in DM patients can improve the outcomes of these procedures needs to be established. Furthermore, DM is a risk factor for contrast-induced acute kidney injury (CI-AKI). The latter should be recorded in DM patients undergoing carotid stenting since it can influence both short- and long-term outcomes. From a pathophysiological perspective, functional changes in the carotid artery may precede morphological ones. Furthermore, carotid plaque characteristics are increasingly being studied in terms of vascular risk stratification and monitoring short-term changes attributed to treatment. The present narrative review discusses the recent (2019) literature on the associations between DM and carotid artery disease. Physicians and vascular surgeons looking after patients with carotid disease and DM should consider these links that may influence outcomes. Further research in this field is also needed to optimise the treatment of such patients.

Why are we still debating criteria for carotid artery stenosis?

The risk of new or recurrent stroke is high among patients with extracranial carotid artery stenosis and the benefit of carotid revascularization is associated to the degree of luminal stenosis. Catheter-based digital subtraction angiography (DSA) as the diagnostic gold-standard for carotid stenosis (CS) has been replaced by non-invasive techniques including duplex ultrasound, computed-tomography angiography, and magnetic resonance angiography (MRA). Duplex ultrasound is the primary noninvasive diagnostic tool for detecting, grading and monitoring of carotid artery stenosis due to its low cost, high resolution, and widespread availability. However, as discussed in this review, there is a wide range of practice patterns in use of ultrasound diagnostic criteria for carotid artery stenosis. To date, there is no internationally accepted standard for the gradation of CS. Discrepancies in ultrasound criteria may result in clinically relevant misclassification of disease severity leading to inappropriate referral, or lack of it, to revascularization procedures, and potential for consequential adverse outcome. The Society of Radiologists in Ultrasound (SRU), either as originally outlined or in a modified form, are the most common criteria applied. However, such criteria have received criticism for relying primarily on peak systolic velocities, a parameter that when used in isolation could be misleading. Recent proposals rely on a multiparametric approach in which the hemodynamic consequences of carotid narrowing beyond velocity augmentation are considered for an accurate stenosis classification. Consensus criteria would provide standardized parameters for the diagnosis of CS and considerably improve quality of care. Accrediting bodies around the world have called for consensus on unified criteria for diagnosis of CS. A healthy debate between professionals caring for patients with CS regarding optimal CS criteria still continues.

Diabetes Mellitus and Noncardiac Atherosclerotic Vascular Disease-Pathogenesis and Pharmacological Treatment Options

Diabetes mellitus (DM) is also a cause of cardiovascular (CV) disease (CVD). Addressing the atherosclerotic CVD (ASCVD) burden in DM should reduce premature death and improve quality of life. Diabetes mellitus-associated ASCVD can lead to complications in all vascular beds (carotids as well as coronary, lower extremity, and renal arteries). This narrative review considers the diagnosis and pharmacological treatment of noncardiac atherosclerotic vascular disease (mainly in patients with DM). Based on current knowledge and the fact that modern DM treatment guidelines are based on CV outcome trials, it should be noted that patients with noncardiac CVD may not have the same benefits from certain drugs compared with patients who predominantly have cardiac complications. This leads to the conclusion that in the future, consideration should be given to conducting well-designed trials that will answer which pharmacological treatment modalities will be of greatest benefit to patients with noncardiac ASCVD.

Rationale for screening selected patients for asymptomatic carotid artery stenosis

Stroke is a leading cause of death and disability worldwide. Approximately 15% of all first-ever strokes occur due to atheroembolism from a previously undetected/untreated asymptomatic carotid stenosis (ACS). Despite that, international guidelines do not recommend screening for ACS. The rationale for not recommending screening include: (a) the harm associated with screening, (b) the questionable clinical benefit associated with surgery, (c) the lack of proven reduction in the risk of stroke, (d) the large number of false positive/false negative tests, and (e) the cost-effectiveness of such screening programs. A critical analysis of each of these arguments is presented. Patients with ACS have a very high risk of all-cause and cardiac mortality. Detection of ACS should not be viewed as an indication for surgery, but rather as an opportunity to implement best medical treatment (BMT) and lifestyle changes to prevent not only strokes, but also cardiac events. The implementation of screening programs for abdominal aortic aneurysms (AAAs) has led to a considerable reduction in the number of ruptured AAAs and AAA-related deaths. Similarly, screening high-risk individuals for ACS would enable timely identification of patients with ACS and implementation of BMT and lifestyle measures to prevent future strokes and cardiac events.

Appropriate Patient Selection for Carotid Revascularization Procedures is Urgently Needed

The identification/selection of appropriate patient subgroups with asymptomatic carotid artery stenosis and the performance of prophylactic carotid endarterectomy (CEA)/carotid artery stenting (CAS) exclusively on these asymptomatic patient subgroups is currently one of the "hottest" topics in vascular surgery. It is now clear that offering CEA/CAS to asymptomatic carotid patients based only on the degree of carotid stenosis is unjustified and scientifically flawed. On the other hand, offering only best medical therapy to every asymptomatic patient, irrespective of certain high-risk criteria (such as the detection of microemboli by transcranial Doppler, intraplaque hemorrhage, silent embolic infarcts on brain computed tomography/magnetic resonance imaging, elevated biomarkers, family history), is equally wrong. The validation of specific measures to identify those asymptomatic patients at high risk for developing symptoms is crucial to achieve optimal use of carotid interventions and avoid wasting stroke prevention resources.

Prevention of Carotid Artery Atherosclerosis: What is the Evidence?

Carotid artery atherosclerosis (CAA) represents a significant form of atherosclerosis with stroke as a major consequence. Whether it is a unique form of atherosclerosis is not established. However, this is not of major clinical relevance as no specific preventive measures over and above the established ones for cardiovascular risk are well established. Major risk factors for CAA are elevated low-density lipoprotein cholesterol (LDL-C), diabetes mellitus, tobacco use, hypertension, and increased inflammation. Identification of CAA prior to a clinical event centers on imaging studies. Studies with magnetic resonance imaging result in the best definition of CAA plaque morphology. Medical measures that result in prevention are especially centered on statins (marked reduction of the LDL-C) and hypertension control. Nonprocedural therapeutic measures to avoid and delay complications involve antiplatelet medications. Benefits from other measures such as increasing high-density lipoprotein cholesterol and increased exercise appear desirable but require more clinical evidence. In conclusion, there are enough evidence-based medicine results to demand intensive medical preventive measures and not just relegate the patient with asymptomatic or symptomatic CAA to decision-making only involving the surgeon and interventionalist.

Evaluation of the clinical utility of a carotid bruit

BACKGROUND

Uncertainty exists over whether listening for carotid bruits as part of the clinical examination is informative in terms of predicting the presence or severity of carotid stenosis.

AIM

We sought to undertake a comprehensive meta-analysis and meta-regression of all studies to date that have assessed the relationship between a carotid bruit and severity of degree of stenosis.

METHODS

Electronic databases were used to identify all published studies in humans evaluating the association between bruit and stenosis published until and including October 2011. Pooled sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each stenosis group. Summary receiver operating characteristic (SROC) curve analysis was performed in studies assessing clinically relevant (i.e. >70%) stenosis. Meta-regression was performed in all studies, using random effects.

RESULTS

We identified 26 studies evaluating the association between carotid bruit and stenosis, in 15 117 arteries. For clinically relevant stenosis (i.e. >70%), we found pooled sensitivity 0.53 [95% confidence interval (CI): 0.5-0.55], specificity 0.83 (95% CI: 0.82-0.84) and DOR 4.32 (95% CI: 2.78-6.66). SROC curve analysis gave an area under the curve of 0.73. Meta-regression analysis showed a (non-significant) (P = 0.067) inverse relationship between carotid bruit and stenosis.

CONCLUSION

The carotid bruit is of moderate value for detecting clinically relevant carotid stenosis. It gives high specificity but low sensitivity. The likelihood of a carotid bruit does not increase at increasing degrees of stenosis.

Extracranial Carotid Stenosis and Peripheral Arterial Disease in Thai Patients With Coronary Artery Disease

We assessed the prevalence of carotid stenosis (CS) and peripheral arterial disease (PAD) in patients with coronary artery disease (CAD) to determine the relationship between these conditions in a Thai population. All patients with coronary angiography during June 2008 and August 2009 were studied. Carotid duplex and ankle-brachial index (ABI) were performed. One hundred and seventy-seven patients were studied (95 men, mean age of 65). Carotid stenosis and PAD were diagnosed in 16 patients (9%) and 68 patients (38.4%), respectively. The presence of carotid bruit and older age were independent predictors of CS and PAD, respectively. There was no correlation between the presence of CS/PAD and the extent of coronary artery lesions. Although CS was uncommon in patients with CAD, the patients with cervical bruit should be screened for CS. Prevalence of PAD was high, confirming the presence of diffuse atherosclerosis in many patients with CAD.