Detection of asymptomatic carotid stenosis in patients with lower-extremity arterial disease: development and external validations of a risk score

Prediction of Severe Baseline Asymptomatic Carotid Stenosis and Subsequent Risk of Stroke and Cardiovascular Disease

BACKGROUND

Risk models to identify patients at high risk of asymptomatic carotid artery stenosis (ACAS) can help in selecting patients for screening, but long-term outcomes in these patients are unknown. We assessed the diagnostic and prognostic value of the previously published Prevalence of ACAS (PACAS) risk model to detect ACAS at baseline and to predict subsequent risk of stroke and cardiovascular disease (CVD) during follow-up.

METHODS

We validated the discrimination and calibration of the PACAS risk model to detect severe (≥70% narrowing) ACAS with patients from the Reduction of Atherothrombosis for Continued Health registry. We subsequently calculated the incidence rates of stroke and CVD (fatal and nonfatal stroke or myocardial infarction or vascular death) during follow-up in 4 risk groups (low, medium, high, and very high, corresponding to sum scores of ≤9, 10-13, 14-17, and ≥18, respectively).

RESULTS

Among 26 384 patients, aged between 45 and 80 years, without prior carotid procedures, 1662 (6.3%) had severe baseline ACAS. During ≈70 000 patient-years of follow-up, 1124 strokes and 2484 CVD events occurred. Discrimination of the PACAS model was 0.67 (95% CI, 0.65-0.68), and calibration showed adequate concordance between predicted and observed risks of severe baseline ACAS after recalibration. Significantly higher incidence rates of stroke (Ptrend<0.011) and CVD (Ptrend<0.0001) during follow-up were found with increasing PACAS risk groups. Among patients with high PACAS sum score of ≥14 (corresponding to 27.7% of all patients), severe baseline ACAS prevalence was 11.4%. In addition, 56.6% of incident strokes and 64.9% of incident CVD events occurred in this group.

CONCLUSIONS

The PACAS risk model can reliably identify patients at high risk of severe baseline ACAS. Incidence rates of stroke and CVD during follow-up were significantly higher in patients with high PACAS sum scores. Selective screening of patients with high PACAS sum scores may help to prevent future stroke or CVD.

Derivation of a clinical prediction score for the diagnosis of clinically significant symptomatic carotid artery disease

OBJECTIVES

Emergent vascular imaging identifies a subset of patients requiring immediate specialized care (i.e. carotid stenosis > 50%, dissection or free-floating thrombus). However, most TIA patients do not have these findings, so it is inefficient to image all TIA patients in crowded emergency departments (ED). Our objectives were to derive and internally validate a clinical prediction score for clinically significant carotid artery disease in TIA patients.

METHODS

This was a planned secondary analysis of a prospective cohort study from 14 Canadian EDs. Among 11555 consecutive adult ED patients with TIA/minor stroke symptoms over 12 years, 9882 had vascular imaging and were included in the analysis. Our main outcome was clinically significant carotid artery disease, defined as extracranial internal carotid stenosis ≥ 50%, dissection, or thrombus in the internal carotid artery, with contralateral symptoms.

RESULTS

Of 9882 patients, 888 (9.0%) had clinically significant carotid artery disease. Logistic regression was used to derive a 13-variable reduced model. We simplified the model into a score (Symcard [Symptomatic carotid artery disease] Score), with suggested cut-points for high, medium, and low-risk stratification. A substantial portion (38%) of patients were classified as low-risk, 33.8% as medium risk, and 28.2% as high risk. At the low-risk cut-point, sensitivity was 92.9%, specificity 41.1%, and diagnostic yield 1.7%.

CONCLUSIONS

This simple score can predict carotid artery disease in TIA patients using readily available information. It identifies low-risk patients who can defer vascular imaging to an outpatient or specialty clinic setting. Medium-risk patients may undergo imaging immediately or with slight delay, depending on local resources. High-risk patients should undergo urgent vascular imaging.

Associations of Increased Red Cell Distribution Width Levels with the Severity of Carotid Artery Stenosis: Cross-sectional Study Results

Background

Red blood cell distribution width (RDW) is being actively studied as a biomarker in various cardiovascular diseases (CVDs). The aim of this study was to conduct a comparative analysis of RDW in patients with carotid atherosclerosis, comparing it with an assessment of the severity of carotid artery stenosis (CAS).

Methods

The Duplex registry database was used to conduct this retrospective cross-sectional study. The study participants underwent a complete blood count test, analysis for lipid profile, and carotid ultrasound. The patients were divided into 5 groups depending on CAS degree: none; 20%-49%; 50%-69%; 70%-99%; and occlusion.

Results

Data from 2548 patients were included in the final analysis (mean age: 57.9 ± 12.3 years; 51% males [n = 1301]). The analysis confirmed the relationship between the increase in the RDW index and CAS gradation increase in men (Kr-W H = 16.43; P = 0.0009), but was not confirmed in women (Kr-W H = 4.32; P = 0.22). Significantly higher levels of high-density lipoprotein cholesterol and platelets and lower levels of red blood cell and white blood cells were registered in female patients without CAS and with CAS < 50% compared with men (P < 0.001).

Conclusion

The results of the present study showed that RDW is an indicator whose increase is associated with an increase in the degree of carotid atherosclerosis in men, but not in women. This allows to discuss the role of the RDW index as a possible new laboratory biomarker of inflammation and progression of atherosclerosis, which can make an additional contribution to the formation of increased morbidity and mortality in men from atherosclerotic CVD.

Evaluation of Short-Term Insulin Pump for Treatment of Patients with Type 2 Diabetes Mellitus Complicated with Lower Extremity Arterial Disease in Endocrinology by Ultrasonography

This research aimed to explore the curative effect of short-term insulin pump in the treatment of type 2 diabetes mellitus (T2DM) patients with lower extremity arterial disease (LEAD) based on ultrasonography. 422 patients (220 males and 202 females) with T2DM in the hospital were selected, and they were randomly divided into control group (n = 211, oral hypoglycemic drugs or diet control, appropriate exercise to lower blood glucose) and experimental group (n = 211, insulin pump was used to reduce blood glucose). After 2 weeks, the therapeutic effect was evaluated by ultrasonography. The results showed that after two weeks of treatment, the difference in lumen intima between the two groups was statistically significant (P < 0.05). The intima-media thickness (IMT) values of the experimental group were 0.83 ± 0.03 mm, 0.62 ± 0.03 mm, and 0.41 ± 0.04 mm, respectively, which were significantly different from those of the control group (1.62 ± 0.54 mm, 1.23 ± 0.14 mm, and 0.78 ± 0.11 mm) (P < 0.05). There was obvious difference in low-density lipoprotein cholesterol (LDL-C) level between the experimental group (2.22 ± 0.46 mmol/L) and the control group (3.21 ± 0.62 mmol/L) (P < 0.05). The LEAD score of the experimental group was 5.51 ± 1.11, which was significantly different from that of the control group (7.08 ± 2.73) (P < 0.05). There was clear difference in LEAD score between the two groups under different course of disease (CD) (P < 0.05). Studies indicated that short-term application of insulin pump therapy could effectively improve the pathological changes of lower limbs in patients with T2DM, which had clinical application value.