Editor's Choice - Cohort Study Examining the Association Between Abdominal Aortic Size and Major Adverse Cardiovascular Events in Patients with Aortic and Peripheral Occlusive and Aneurysmal Disease

Rates of Stroke in Patients With Different Presentations of Carotid Artery Stenosis

OBJECTIVE

Carotid artery stenosis may present without the classical symptoms of transient ischaemic attack or stroke but the rates of stroke for these presentations is unknown. The aim of this study was to examine the rates of stroke in patients with different presentations of carotid artery stenosis.

METHODS

A multicentre prospective cohort study was conducted across three Australian vascular centres with low rates of surgical treatment of patients without transient ischaemic attack or stroke. Patients with a 50 - 99% carotid artery stenosis presenting with non-focal symptoms (e.g., dizziness or syncope; n = 47), prior contralateral carotid endarterectomy (n = 71), prior ipsilateral symptoms more than six months earlier (n = 82), and no symptoms (n = 304) were recruited. The primary outcome was ipsilateral ischaemic stroke. Secondary outcomes were any ischaemic stroke and cardiovascular death. Data were analysed using Cox proportional hazard and Kaplan-Meier analyses.

RESULTS

Between 2002 and 2020, 504 patients were enrolled (mean age 71 years, 30% women) and followed for a median of 5.1 years (interquartile range 2.5, 8.8; 2 981 person years). Approximately 82% were prescribed antiplatelet therapy, 84% were receiving at least one antihypertensive drug, and 76% were prescribed a statin at entry. After five years the incidence of ipsilateral stroke was 6.5% (95% confidence interval [CI] 4.3 - 9.5). There were no statistically significant differences in the annual rate of ipsilateral stroke among people with non-focal symptoms (2.1%; 95% CI 0.8 - 5.7), prior contralateral carotid endarterectomy (0.2%; 0.03 - 1.6) or ipsilateral symptoms > 6 months prior (1.0%; 0.4 - 2.5) compared with those with no symptoms (1.2%; 0.7 - 1.8; p = .19). There were no statistically significant differences in secondary outcomes across groups.

CONCLUSION

This cohort study showed no large differences in stroke rates among people with different presentations of carotid artery stenosis.

The Incidence of IgG4-Related and Inflammatory Abdominal Aortic Aneurysm Is Rare in a 101 Patient Cohort

Abdominal aortic aneurysms (AAA) are the most frequent aortic dilation, with considerable morbidity and mortality. Inflammatory (infl) and IgG4-positive AAAs represent specific subtypes of unclear incidence and clinical significance. Here, histologic and serologic analyses with retrospective clinical data acquisition are investigated via detailed histology, including morphologic (HE, EvG: inflammatory subtype, angiogenesis, and fibrosis) and immunhistochemic analyses (IgG and IgG4). In addition, complement factors C3/C4 and immunoglobulins IgG, IgG2, IgG4 and IgE were measured in serum samples and clinical data uses patients' metrics, as well as through semi-automated morphometric analysis (diameter, volume, angulation and vessel tortuosity). A total of 101 eligible patients showed five (5%) IgG4 positive (all scored 1) and seven (7%) inflammatory AAAs. An increased degree of inflammation was seen in IgG4 positive and inflAAA, respectively. However, serologic analysis revealed no increased levels of IgG or IgG4. The operative procedure time was not different for those cases and the short-term clinical outcomes were equal for the entire AAA cohort. Overall, the incidence of inflammatory and IgG4-positive AAA samples seems very low based on histologic and serum analyses. Both entities must be considered distinct disease phenotypes. Short-term operative outcomes were not different for both sub-cohorts.

Association of Oral Anticoagulation Prescription with Clinical Events in Patients with an Asymptomatic Unrepaired Abdominal Aortic Aneurysm

Background: Most abdominal aortic aneurysms (AAA) have large volumes of intraluminal thrombus which has been implicated in promoting the risk of major adverse events. The aim of this study was to examine the association of therapeutic anticoagulation with AAA-related events and major adverse cardiovascular events (MACE) in patients with an unrepaired AAA. Methods: Patients with an asymptomatic unrepaired AAA were recruited from four sites in Australia. The primary outcome was the combined incidence of AAA repair or AAA rupture-related mortality (AAA-related events). The main secondary outcome was MACE (the combined incidence of myocardial infarction, stroke, or cardiovascular death). The associations of anticoagulation with these outcomes were assessed using Cox proportional hazard analyses (reporting hazard ratio, HR, and 95% confidence intervals, CI) to adjust for other risk factors. Results: A total of 1161 patients were followed for a mean (standard deviation) of 4.9 (4.0) years. Of them, 536 (46.2%) patients had a least one AAA-related event and 319 (27.5%) at least one MACE. In the sample, 98 (8.4%) patients were receiving long-term therapeutic anticoagulation using warfarin (84), apixaban (7), rivaroxaban (6), or dabigatran (1). Prescription of an anticoagulant was associated with a reduced risk of an AAA-related event (adjusted HR 0.61; 95% CI 0.42, 0.90, p = 0.013), but not MACE (HR 1.16; 95% CI 0.78, 1.72, p = 0.476). Conclusions: These findings suggest that AAA-related events but not MACE may be reduced in patients prescribed an anticoagulant medication. Due to the inherent biases of observational studies, a randomized controlled trial is needed to assess whether anticoagulation reduces the risk of AAA-related events.

Aortic Area as an Indicator of Subclinical Cardiovascular Disease

Aim:

Outward arterial remodeling occurs early in cardiovascular disease (CVD) and, as such, measuring arterial dimension may be an early indicator of subclinical disease.

Objective:

The objective of our study was to measure area at three aortic locations: The ascending thoracic (ASC), the descending thoracic (DSC), and the abdominal (ABD), and to test for association with traditional CVD risk factors and subclinical CVD throughout the body.

Methods:

We measured ASC, DSC, and ABD using computed tomography (CT) in 408 African ancestry men aged 50-89 years. We assessed prevalent CVD risk factors via participant interview and clinical exam, and subclinical CVD, including carotid atherosclerosis through B-mode carotid ultrasound, vascular calcification via chest and abdominal CT, and arterial stiffness via pulse-wave velocity (PWV).

Results:

As expected, all aortic areas were in correlation with each other (r=0.39-0.63, all p<0.0001) and associated with greater age, greater body size, and hypertension (p≤0.01 for all). After adjustment for traditional CVD risk factors, ASC was positively associated with carotid atherosclerosis (p<0.01). A greater area at each location was associated with greater PWV (p<0.03 for all), with the DSC region showing the most significant association.

Conclusion:

This is the first study to test the association of aortic area measured at multiple points with subclinical CVD. We found that combined CT assessment of ascending and descending aortic area may indicate a high risk of prevalent subclinical CVD elsewhere in the body independent of age, body size, and blood pressure.