The indication of transesophageal echocardiography (TEE) in acute stroke is unclear. Thus, we systematically studied the impact of TEE on determining stroke etiology and secondary prevention in ...patients of different age-groups with cryptogenic stroke.
Four hundred and eighty five consecutive patients with acute retinal or cerebral ischemia were prospectively included and underwent routine stroke workup including TEE. Stroke etiology was identified according to the TOAST classification and patients were divided in those with determined and cryptogenic stroke etiology without TEE results. Then, the frequency of high- and potential-risk sources in TEE was evaluated in <55, 55-74, and ≥75 year-old patients with cryptogenic stroke etiology.
Without TEE, stroke etiology was cryptogenic in 329(67.8%) patients and TEE determined possible etiology in 158(48.4%) of them. In patients aged <55, 55-74, ≥75, TEE detected aortic arch plaques ≥4 mm thickness in 2(1.2%), 37(23.0%), and 33(40.2%) and plaques with superimposed thrombi in 0(0.0%), 5(3.1%), and 7(8.5%); left atrial appendage peak emptying flow velocity ≤30cm/s in 0(0.0%), 1(0.6%), and 2(2.4%), spontaneous echo contrast in 0(0.0%), 1(0.6%), and 6(7.3%), endocarditis in 0(0.0%), 0(0.0%), and 1(1.2%) and patent foramen ovale (PFO) plus atrial septum aneurysm (ASA) in 18(20.9%), 32(19.9%), and 14(17.1%), respectively. TEE changed secondary prevention in 16.4% of these patients following guidelines of 2010/11 and still 9.4% when applying the guidelines of 2020.
TEE was highly valuable for determining stroke etiology and influenced individual secondary prevention based on available treatment guidelines and expert opinion in most cases. In young patients the impact of TEE was limited to the detection of septal anomalies. By contrast, in older patients TEE detected high numbers of complex aortic atheroma and potential indicators of paroxysmal atrial fibrillation.
Objectives
Retrograde blood flow from complex atheroma in the descending aorta (DAo) has only recently been described as a potential mechanism of stroke. However, prevalence of this mechanism in the ...general population and the exact factors influencing stroke risk are unclear.
Methods
One hundred twenty-six consecutively recruited inhabitants of Freiburg, Germany, between 20 and 80 years of age prospectively underwent 3-T MRI. Aortic plaque location and thickness were determined by 3D T1 MRI (1 mm
3
). 4D flow MRI (spatial/temporal resolution 2 mm
3
/20 ms) and dedicated software were used to determine prevalence and extent of flow reversal and potential embolization from DAo plaques. Flow was correlated with baseline characteristics and echocardiographic and MRI parameters (aortic diameter, wall thickness, and pulse wave velocity).
Results
The maximum length of retrograde blood flow connecting the DAo with the left subclavian artery (LSA) increased from 16.1 ± 8.3 mm in 20–29-year-old to 24.7 ± 11.7 mm in 70–80-year-old subjects, correlated with age (
r
= 0.37;
p
< 0.001), and was lower in females (
p
= 0.003). Age was the only independent predictor of increased flow reversal. Complex DAo plaques ≥ 4-mm thickness were found in eight subjects (6.3%) and were connected with the LSA, left common carotid artery, and brachiocephalic trunk in 8 (100%), 1 (12.5%), and 0 (0%) cases, respectively.
Conclusions
Retrograde blood flow from the DAo was very frequent. However, potential retrograde embolization was rare due to the low incidence of complex DAo plaques. The magnitude of flow reversal and prevalence of complex atheroma increased with age. Thus, older patients with aortic atherosclerosis are especially vulnerable to this stroke mechanism.
Key Points
•
4D flow MRI allows in vivo visualization and quantification of individual and three-dimensional blood flow patterns within the thoracic aorta including retrograde components.
•
This population-based study showed that blood flow reversal from the proximal descending aorta to the brain-supplying great arteries is very frequent and able to reach all brain territories. The extent of such flow reversal increases with age and with the extent of aortic atherosclerosis.
•
The combination of blood flow reversal with plaque rupture in the proximal descending aorta constitutes a potential stroke mechanism that should be considered in future trials and in the management of stroke patients in clinical routine.
Increased aortic stiffness is an independent predictor of cardiovascular disease. Optimal measurement is highly beneficial for the detection of atherosclerosis and the management of patients at risk. ...Thus, it was our purpose to selectively measure aortic stiffness using a novel imaging method and to provide reference values from a population-based study.
One hundred twenty six inhabitants of Freiburg, Germany, between 20 and 80 years prospectively underwent 3 Tesla cardiovascular magnetic resonance (CMR) of the thoracic aorta. 4D flow CMR (spatial/temporal resolution 2mm
/20ms) was executed to calculate aortic pulse wave velocity (PWV) in m/s using dedicated software. In addition, we calculated distensibility coefficients (DC) using 2D CINE CMR imaging of the ascending (AAo) and descending aorta (DAo). Segmental aortic diameter and thickness of aortic plaques were determined by 3D T1 weighted CMR (spatial resolution 1mm
).
PWV increased from 4.93 ± 0.54 m/s in 20-30 year-old to 8.06 ± 1.03 m/s in 70-80 year-old subjects. PWV was significantly lower in women compared to men (p < 0.0001). Increased blood pressure (systolic r = 0.36, p < 0.0001; diastolic r = 0.33, p = 0.0001; mean arterial pressure r = 0.37, p < 0.0001) correlated with PWV after adjustment for age and gender. Finally, PWV increased with increasing diameter of the aorta (ascending aorta r = 0.20, p = 0.026; aortic arch r = 0.24, p = 0.009; descending aorta r = 0.26, p = 0.004). Correlation of PWV and DC of the AAo and DAo or the mean of both was high (r = 0.69, r = 0.68, r = 0.73; p < 0.001).
4D flow CMR was successfully applied to calculate aortic PWV and thus aortic stiffness. Findings showed a high correlation with distensibility coefficients representing local compliance of the aorta. Our novel method and reference data for PWV may provide a reliable biomarker for the identification of patients with underlying cardiovascular disease and optimal guidance of future treatment in studies or clinical routine.
We comprehensively studied morphological and functional aortic aging in a population study using modern three-dimensional MR imaging to allow future comparison in patients with diseases of the aortic ...valve or aorta. We followed 80 of 126 subjects of a population study (20 to 80 years of age at baseline) using the identical methodology 6.0 ± 0.5 years later. All underwent 3 T MRI of the thoracic aorta including 3D T1 weighted MRI (spatial resolution 1 mm
) for measuring aortic diameter and plaque thickness and 4D flow MRI (spatial/temporal resolution = 2 mm
/20 ms) for calculating global and regional aortic pulse wave velocity (PWV) and helicity of aortic blood flow. Mean diameter of the ascending aorta (AAo) decreased and plaque thickness increased significantly in the aortic arch (AA) and descending aorta (DAo) in females. PWV of the thoracic aorta increased (6.4 ± 1.5 to 7.0 ± 1.7 m/s and 6.8 ± 1.5 to 7.3 ± 1.8 m/s in females and males, respectively) over time. Local normalized helicity volumes (LNHV) decreased significantly in the AAo and AA (0.33 to 0.31 and 0.34 to 0.32 in females and 0.34 to 0.32 and 0.32 to 0.28 in males). By contrast, helicity increased significantly in the DAo in both genders (0.28 to 0.29 and 0.29 to 0.30, respectively). 3D MRI was able to characterize changes in aortic diameter, plaque thickness, PWV and helicity during six years in our population. Aortic aging determined by 3D multi-parametric MRI is now available for future comparisons in patients with diseases of the aortic valve or aorta.
Background Genetic and nongenetic factors account for the association of family history with disease risk. Comparing adopted and nonadopted individuals provides an opportunity to disentangle those ...factors. Methods and Results We examined associations between family history of stroke and heart disease with incident stroke and myocardial infarction (MI) in 495 640 UK Biobank participants (mean age, 56.5 years; 55% women) stratified by childhood adoption status (5747 adoptees). We estimated hazard ratios (HRs) per affected family member, and for polygenic risk scores in Cox models adjusted for baseline age and sex. A total of 12 518 strokes and 23 923 MIs occurred over a 13-year follow-up. In nonadoptees, family history of stroke and heart disease was associated with increased stroke and MI risk, with the strongest association of family history of stroke for incident stroke (HR, 1.16 95% CI, 1.12-1.19) and family history of heart disease for incident MI (HR, 1.48 95% CI, 1.45-1.50). In adoptees, family history of stroke associated with incident stroke (HR, 1.41 95% CI, 1.06-1.86), but family history of heart disease was not associated with incident MI (
>0.5). Polygenic risk scores showed strong disease-specific associations in both groups. In nonadoptees, the stroke polygenic risk score mediated 6% risk between family history of stroke and incident stroke, and the MI polygenic risk score mediated 13% risk between family history of heart disease and incident MI. Conclusions Family history of stroke and heart disease increases risk for their respective conditions. Family history of stroke contains substantial potentially modifiable nongenetic risk, indicating a need for novel prevention strategies, whereas family history of heart disease represents predominantly genetic risk.
The posterior wall of the proximal internal carotid artery (ICA) is the predilection site for the development of stenosis. To optimally prevent stroke, identification of new risk factors for plaque ...progression is of high interest. Therefore, we studied the impact of carotid geometry and wall shear stress on cardiovascular magnetic resonance (CMR)-depicted wall thickness in the ICA of patients with high cardiovascular disease risk.
One hundred twenty-one consecutive patients ≥50 years with hypertension, ≥1 additional cardiovascular risk factor and ICA plaque ≥1.5 mm thickness and < 50% stenosis were prospectively included. High-resolution 3D-multi-contrast (time of flight, T1, T2, proton density) and 4D flow CMR were performed for the assessment of morphological (bifurcation angle, ICA/common carotid artery (CCA) diameter ratio, tortuosity, and wall thickness) and hemodynamic parameters (absolute/systolic wall shear stress (WSS), oscillatory shear index (OSI)) in 242 carotid bifurcations.
We found lower absolute/systolic WSS, higher OSI and increased wall thickness in the posterior compared to the anterior wall of the ICA bulb (p < 0.001), whereas this correlation disappeared in ≥10% stenosis. Higher carotid tortuosity (regression coefficient = 0.764; p < 0.001) and lower ICA/CCA diameter ratio (regression coefficient = - 0.302; p < 0.001) were independent predictors of increased wall thickness even after adjustment for cardiovascular risk factors. This association was not found for bifurcation angle, WSS or OSI in multivariate regression analysis.
High carotid tortuosity and low ICA diameter were independent predictors for wall thickness of the ICA bulb in this cross-sectional study, whereas this association was not present for WSS or OSI. Thus, consideration of geometric parameters of the carotid bifurcation could be helpful to identify patients at increased risk of carotid plaque generation. However, this association and the potential benefit of WSS measurement need to be further explored in a longitudinal study.
To analyze the outcome of near-infrared spectroscopy (NIRS)-guided selective shunting during carotid endarterectomy and the procedural outcome.
In this retrospective single-center study, patients ...undergoing carotid endarterectomy in general anesthesia and receiving bihemispheric NIRS as single neuromonitoring tool between January 2009 and January 2014 were included. Shunting was applied if the reduction in the NIRS values after cross-clamping on the ipsilateral side exceeded 15%. Patients with contralateral occlusion of the internal carotid artery (ICA) were excluded, as were patients operated on by surgeons performing routine shunting. All patients underwent intraoperative angiography after vessel recanalization.
NIRS trend was available in 441 patients. Twenty-eight were excluded from this study (14 due to preference for general shunting, 13 due to contralateral ICA occlusion, and 1 due to intraoperative ICA occlusion), resulting in a final sample of 413 patients. We observed a >15% drop in NIRS values on the ipsilateral side in 29 (7%) patients. Accordingly, an intraluminal shunt was placed into the ICA. Shunting was not performed in 384 patients (<15% drop in NIRS values). Interestingly, the NIRS values on the contralateral side were significantly elevated after cross-clamping compared with baseline in the group without shunt (P < 0.0001). On the contrary, patients requiring an ICA shunt revealed a statistically significant reduction in the rSO
on the contralateral side compared with the baseline (after ipsilateral clamping) (P = 0.047). Three patients overall suffered a stroke, all of whom were in the no-shunt group (combined stroke rate of 0.8% 3/384 with no significant intergroup difference). There was no difference in morbidity factors between the two groups. However, surgical revision after intraoperative angiography was significantly more frequent in the shunt group (17.2%, 5/29) versus the no-shunt group (6%, 23/384), (P < 0.037).
An NIRS-guided selective shunting strategy was associated with excellent clinical outcomes and has the potential to identify patients at risk for hypoperfusion during the clamping period. However, a potentially shunt-associated higher rate of requiring local revisions (due to flaps, twisting, stenosis, and kinking) in ICA was observed. Additional studies are needed to further refine cut-off values for NIRS, indicating the need for shunting.
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