Protruding atherosclerotic aortic plaques and dyslipidaemia: correlation to subtypes of ischaemic stroke

Epidemiology of cardiovascular disease in Japan: An overview study

Cardiovascular diseases (CVDs), such as heart disease and stroke, have a significant impact on life expectancy, healthy life expectancy, and medical costs in Japan. Each prefecture is currently promoting measures in accordance with the Japanese National Plan for Promotion of Measures Against Cerebrovascular and Cardiovascular Disease, which was established by the government. In recent years, the crude mortality rate of heart disease in Japan has been increasing year by year with the aging population. Meanwhile, the age-adjusted mortality rate has leveled off or shown a downward trend. In addition, the proportion of acute myocardial infarction has decreased, whereas the proportion of heart failure has increased. By contrast, both the crude and age-adjusted mortality rates of stroke have a declining trend. Nevertheless, considering the potential variations in death certificates issued for patients with myocardial infarction across different prefectures, it is crucial to determine the incidence of CVD in each prefecture for the accurate assessment of CVD trends. However, as for the incidence of CVD, not many prefectures have yet implemented registration programs. The age-adjusted incidence rate of acute myocardial infarction has been increasing in some areas and decreasing in others since 1990. The age-adjusted incidence rate of stroke has consistently declined since the 1960s. Nevertheless, the possible increase in the incidence rate of cerebral embolism and thrombotic cerebral infarction among patients with different stroke subtypes is a cause of concern. The impact of heart failure on the incidence of heart disease has increased. Therefore, relevant academic societies and prefectures must collaborate in registering the incidence of heart failure as well as myocardial infarction and implementing countermeasures.

Aortic arch atheroma and the risk of stroke: a meta-analysis

BACKGROUNDS AND OBJECTIVES

Epidemiological studies have suggested that aortic atheroma may play a role in cerebral embolization; however, no meta-analysis was conducted to evaluate the relationship between aortic atheroma and risk of stroke. The aim of this study was to investigate the association between the presence of aortic atheroma and risk of stroke.

METHODS

We performed a comprehensive search of observational studies reporting the relationship between the presence of aortic atheroma and stroke using the PubMed, EMbase, the China National Knowledge Infrastructure database (CNKI), Chinese Technical Periodicals (VIP), and WanFang Data databases. Two reviewers independently assessed the eligibility and extracted data from the included studies. We performed the meta-analysis to estimate the strength of the association according to Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline and assessed the study quality by the Newcastle-Ottawa Scale (NOS).

RESULTS

We identified 12 eligible studies with 3918 participants. The scores of the NOS of the included studies ranged from 5 to 9. The pooled estimate of strength of the association between the presence of aortic atheroma and stroke was statistical significant (OR = 3.93, 95%CI 2.86 to 5.40). In subgroup analysis according to plaques' morphology, complex aortic atheroma had significantly higher (OR = 5.90, 95%CI 4.14 to 8.41) risk of stroke than protruding atheroma (OR = 3.75, 95%CI 3.05 to 4.61).

CONCLUSIONS

This study indicated that aortic atheroma significantly increased the risk of stroke by about four times. Patients with complex aortic atheroma have a higher risk of stroke than protruding atheroma.

Complex atheromatous plaques in the descending aorta and the risk of stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Proximal aortic plaques, especially in the aortic arch, have already been established as an important cause of stroke and peripheral embolism. However, aortic plaques situated in the descending thoracic aorta have recently been postulated as a potential embolic source in patients with cryptogenic cerebral infarction through retrograde aortic flow. The aim of the present study was to evaluate the potential association of descending aorta atheromatosis with cerebral ischemia.

METHODS

We conducted a systematic review and meta-analysis of all available prospective observational studies reporting the prevalence of complex atheromatous plaques in the descending aorta in patients with stroke and in unselected populations undergoing examination with transesophageal echocardiography.

RESULTS

We identified 11 eligible studies including a total of 4000 patients (667 patients with stroke and 3333 unselected individuals; mean age, 65 years; 55% men). On baseline transesophageal echocardiograpic examination, the prevalence of complex atheromatous plaques in the descending aorta was higher (P=0.001) in patients with stroke (25.4%; 95% confidence interval, 14.6-40.4%) compared with unselected individuals (6.1%; 95% confidence interval, 3.4-10%). However, no significant difference (P=0.059) in the prevalence of complex atheromatous plaques in the descending aorta was found between patients with cryptogenic (21.8%; 95% confidence interval, 17.5-26.9%) and unclassified (28.3%; 95% confidence interval, 23.9-33.1%) cerebral infarction.

CONCLUSIONS

Our findings indicate that the presence of complex plaques in the descending aorta is presumably a marker of generalized atherosclerosis and high vascular risk. The present analyses do not provide any further evidence for a direct causal relationship between descending aorta atherosclerosis and cerebral embolism.

Comparison of frequencies of patent foramen ovale and thoracic aortic atherosclerosis in patients with cryptogenic ischemic stroke undergoing transesophageal echocardiography

Studies have shown an association between the presence of a patent foramen ovale (PFO) and cryptogenic stroke (CS) in patients aged <55 years. In addition, protruding atheromatous plaques in the ascending aorta and aortic arch are an independent risk factor for ischemic stroke in patients aged ≥55 years. The aim of this study was to determine the association of CS in the 2 age groups with PFO and with atheromatous plaques in the ascending aorta and in the aortic arch. Transesophageal echocardiograms in 229 patients evaluated for CS were compared to those in 314 patients evaluated for cardiac disease other than PFO with no histories of stroke (the control group). The prevalence of PFO and the presence of complex atheromatous plaques in the ascending aorta and aortic arch were determined in all patients and compared between the CS and control patients in the 2 age groups. The prevalence of PFO was significantly higher in patients with CS than in control patients among those aged <55 years (31 of 114 [27%] vs 24 of 171 [14%], p = 0.006) and those aged ≥55 years (28 of 115 [24%] vs 21 of 143 [15%], p = 0.049). The incidence of atrial septal aneurysm was similar in the 2 groups irrespective of patient age, as was the prevalence of complex atheromatous plaques. Multivariate analysis showed that PFO was independently associated with CS, irrespective of patient age (<55 years: odds ratio 2.4, 95% confidence interval 1.3 to 4.5, p = 0.01; ≥55 years: odds ratio 1.9, 95% confidence interval 1.1 to 3.5, p = 0.03). In conclusion, PFO was significantly associated with CS in younger (aged <55 years) and older (aged ≥55 years) patients. Atrial septal aneurysm and complex atheromas in the ascending aorta and aortic arch do not appear to be associated with CS.

Stroke severity predicted by aortic atheroma detected by ultra-fast and cardiac-gated chest tomography

Background and Purpose: The presence of aortic atherosclerosis is an independent risk factor for secondary stroke. The present study was designed to have an initial exploration of the correlation between the load and extent of aortic atheroma (AA) and initial stroke severity or clinical outcome 3 months after stroke. Methods: Cardiac-gated chest tomography (CGCT) was used to detect and measure AA in patients with acute ischemic stroke as shown by our group in prior prospective studies and this is part four sub-exploratory study of the same cohort. The National Institute of Health Stroke Scale (NIHSS) was used to assess the initial stroke severity, and the modified Rankin Scale (mRS) was used to assess 3-month outcome. Results: Thirty-two patients underwent CGCT for evaluation of AA, and 21 were found to have AA. AA was more prevalent in patient with NIHSS >6 (14/17 versus 7/15, p-value 0.03). Applying the multiple logistic regression and propensity score adjustment (using the propensity of having AA given the baseline features as covariates) showed a non-significant trend that AA is three times more likely to be associated with NIHSS >6 (p = 0.08, OR 3.08, 95% CI 0.94–13.52). There was no evidence of association of AA with 3-month functional outcome (mRS): 11/14 (78.6%) mRS >1 had AA, and 10/18 (55.5%) of those with mRS ≤1 had AA (p = 0.27). Conclusion: In our current study with limited sample number and exploratory nature, the presence of AA on CGCT with acute ischemic stroke patients may be associated with worse neurological deficit at presentation. There was no evidence of association with 3-month functional outcome using the mRS.

Complex atheromatosis of the aortic arch in cerebral infarction

In many stroke patients it is not possible to establish the etiology of stroke. However, in the last two decades, the use of transesophageal echocardiography in patients with stroke of uncertain etiology reveals atherosclerotic plaques in the aortic arch, which often protrude into the lumen and have mobile components in a high percentage of cases. Several autopsy series and retrospective studies of cases and controls have shown an association between aortic arch atheroma and arterial embolism, which was later confirmed by prospectively designed studies. The association with ischemic stroke was particularly strong when atheromas were located proximal to the ostium of the left subclavian artery, when the plaque was ≥ 4 mm thick and particularly when mobile components are present. In these cases, aspirin might not prevent adequately new arterial ischemic events especially stroke. Here we review the evidence of aortic arch atheroma as an independent risk factor for stroke and arterial embolism, including clinical and pathological data on atherosclerosis of the thoracic aorta as an embolic source. In addition, the impact of complex plaques (≥ 4 mm thick, or with mobile components) on increasing the risk of stroke is also reviewed. In non-randomized retrospective studies anticoagulation was superior to antiplatelet therapy in patients with stroke and aortic arch plaques with mobile components. In a retrospective case-control study, statins significantly reduced the relative risk of new vascular events. However, given the limited data available and its retrospective nature, randomized prospective studies are needed to establish the optimal secondary prevention therapeutic regimens in these high risk patients.

Aortic arch atheroma

Severe atheroma of the aortic arch has now been established as an important risk factor and mechanism for stroke and peripheral embolism. The odds ratio for stroke or peripheral embolism in patients with severe arch atheroma is greater than four, and for mobile atheroma it is greater than 12. The prevalence of severe arch atheroma among patients presenting with acute ischaemic stroke, at over 20%, is in the same order as that of atrial fibrillation and carotid atherosclerosis. In patients with ischaemic stroke for which no cause has been identified, it is reasonable to determine as to whether they have severe arch atheroma by performing a transoesophageal echocardiogram. Recurrent stroke is common in patients with aortic arch atheroma that are thicker than 4 mm or with mobile components, particularly in the elderly, cigarette smokers, and those with hypertension or diabetes. Patients found to have severe atheroma are at high risk of recurrent events (14.2% per year) and may, therefore, need an aggressive secondary prevention strategy. Currently, there is uncertainty as to what this should be, but either combination antiplatelet therapy (aspirin plus clopidogrel) or anticoagulation with warfarin (target INR 2.0-3.0) are commonly used. Which of these is most effective will be evident after the completion of the aortic arch related cerebral hazard trial.

Silent cerebral infarction in patients with dilated cardiomyopathy: Echocardiographic correlates

BACKGROUND

Patients with dilated cardiomyopathy (DCM) have an increased risk of thromboembolic events. Incidence of silent cerebral infarction (SCI) has not been investigated in these patients. The aim of this study was to investigate the incidence of SCI in patients with DCM and to determine its associations with echocardiographic parameters.

METHODS AND RESULTS

Seventy-two patients (mean age 62+/-12 years) with DCM underwent cranial magnetic resonance imaging in addition to transthoracic and transesophageal echocardiographic examination. A total of 56 age-matched healthy volunteers served as a control group for comparison SCI prevalence. Prevalence of SCI was significantly higher in patients with DCM (35% vs. 3.6%; p<0.001). In DCM group, patients with SCI had significantly impaired left ventricular systolic function, higher frequency of restrictive diastolic filling, moderate to severe left atrial spontaneous echo contrast (SEC), aortic SEC, and complex atherosclerosis or calcified plaques in the aorta. In logistic regression analysis, type of diastolic filling emerged as the only independent risk factor for SCI (p<0.001). When the type of diastolic filling was removed from the analysis, ejection fraction, marked left atrial SEC, complex-calcified aortic atheroma and age appeared as the other independent risk factors (p = 0.003, p = 0.009, p = 0.013 and p = 0.018, respectively).

CONCLUSION

SCI is a frequent finding in DCM patients. Impaired systolic function, restrictive filling pattern, presence of moderate to severe left atrial SEC, and complex atherosclerosis in the aorta are the factors contributing to the development of SCI.

Atheroma of the aortic arch: an important and poorly recognised factor in the aetiology of stroke

Atrial fibrillation and severe carotid-artery stenosis are well-characterised risk factors for stroke; each is present in about a fifth of patients. The identification of such risk factors in patients is important because their presence calls for specific secondary prevention strategies. One region of the circulation that has received limited attention as a source of thrombus is the aortic arch. However, aortic arch atheroma is a common post-mortem finding, and it seems reasonable to speculate that atheroma might give rise to thrombi with distal embolism to the arterial tree, including the cerebral circulation. Here we review the evidence for aortic-arch atheroma as an important independent risk factor for stroke, and show that studies of the risk of stroke indicate a four times greater odds of stroke in patients with severe arch atheroma.