Distribution, severity and risk factors for aortic atherosclerosis in cerebral ischemia

Stroke risk after transcatheter aortic valve replacement in patients with carotid stenosis: A systematic review and meta-analysis

BACKGROUND

Stroke is a feared complication of transcatheter aortic valve replacement (TAVR). Patients undergoing TAVR typically have multiple comorbidities, such as carotid artery stenosis (CAS). We conducted the present meta-analysis to determine the risk of stroke and mortality following TAVR in patients with CAS.

METHODS

We searched PubMed/Medline, Scopus, ScienceDirect, and Cochrane Clinical Trials databases for clinical studies that compared CAS ≥50% and CAS ≥70% versus non-CAS TAVR population. The endpoints included the 30-day incidence of stroke or transient ischemic attack (TIA) and 30-day all-cause of mortality.

RESULTS

We identified seven studies that included 12,418 patients in the CAS group and 102,316 in the control group. CAS ≥50% was not associated with an increased risk of 30-day stroke or TIA after TAVR [risk ratio (RR): 1.38; 95% confidence interval (95% CI): 0.95-2.02; p = 0.09]. However, patients with CAS ≥70% had an increased risk of stroke or TIA (RR: 1.43; 95% CI: 1.02-2.01; p = 0.04). No difference in 30-day all-cause mortality was observed between CAS ≥50% or CAS ≥70% and control groups (RR: 1.09; 95% CI: 0.79-1.52; p = 0.59 and RR: 1.11; 95% CI: 0.85-1.45; p = 0.43, respectively).

CONCLUSIONS

CAS ≥70% was associated with an increased risk of stroke or TIA following TAVR compared with patients without CAS.

Synchronous Carotid Endarterectomy and Anaortic Off-Pump Coronary Artery Bypass Surgery

BACKGROUND

There is ongoing debate regarding the optimal strategy and timing for the surgical management of patients with severe concomitant carotid and coronary artery disease. Anaortic off-pump coronary artery bypass (anOPCAB), which avoids aortic manipulation and cardiopulmonary bypass, has been shown to reduce the risk of perioperative stroke. We present the outcomes of a series of synchronous carotid endarterectomy (CEA) and anOPCAB.

METHODS

A retrospective review was performed. The primary endpoint was stroke at 30 days post-operation. Secondary endpoints included transient ischaemic attack, myocardial infarction and mortality 30 days post-operation.

RESULTS

From 2009 to 2016, 1,041 patients underwent anOPCAB with a 30-day stroke rate of 0.4%. The majority of patients had preoperative carotid-subclavian duplex ultrasound screening and 39 were identified with significant concomitant carotid disease who underwent synchronous CEA-anOPCAB. The mean age was 71±7.5 years. Nine patients (23.1%) had previous neurological events. Thirty (30) patients (76.9%) underwent an urgent operation. For CEA, a conventional longitudinal carotid endarterectomy with patch angioplasty was performed in all patients. For anOPCAB, total arterial revascularisation rate was performed in 84.6% and the mean number of distal anastomoses was 2.9±0.7. In the 30-day postoperative period, there was one stroke (2.63%), two deaths (5.26%), two transient ischemic attacks (TIAs) (5.26%) and no myocardial infarction. Two patients experienced acute kidney injury (5.26%), one of which required haemodialysis (2.63%). Mean length of stay was 11.37±7.9 days.

CONCLUSION

Synchronous CEA and anOPCAB is a safe and effective option for patients' severe concomitant disease. Preoperative carotid-subclavian ultrasound screening allows identification of these patients.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Transradial approach for diagnostic cerebral angiograms in the elderly: a comparative observational study

Background

The transradial approach (TRA) reduces mortality, morbidity, access site complications, hospital cost, and length of stay while maximizing patient satisfaction. We aimed to assess the technical success and safety of TRA for elderly patients (aged ≥75 years).

Methods

A retrospective chart review and comparative analysis was performed for elderly patients undergoing a diagnostic cerebral angiogram performed via TRA versus transfemoral approach (TFA). Also, a second comparative analysis was performed among the TRA cohort between elderly patients and their younger counterparts.

Results

Comparative analysis in the elderly (TRA vs TFA) showed no significant differences for contrast dose per vessel (43.7 vs 34.6 mL, P=0.106), fluoroscopy time per vessel (5.7 vs 5.2 min, P=0.849), procedure duration (59.8 vs 65.2 min, P=0.057), conversion rate (5.8% vs 2.9%, P=0.650), and access site complications (2.3% vs 2.9%, P=1.00). Radiation exposure per vessel (18.9 vs 51.9 Gy cm2, P=0.001) was significantly lower in the elderly TRA group.

The second comparison (TRA in elderly vs TRA in the young) showed no significant differences for contrast dose per vessel (43.7 vs 37.8 mL, P=0.185), radiation exposure per vessel (18.9 vs 16.5 Gy cm2, P=0.507), procedure duration (59.8 vs 58.3 min, P=0.788), access site complication (2.3% vs 1.7%, P=0.55), and conversation rate (5.8% vs 1.8%, P=0.092). A trend for prolonged fluoroscopy time per vessel (5.7 vs 4.7 min, P=0.050) was observed in the elderly TRA group.

Conclusions

TRA is a technically feasible and safe option for diagnostic neurointerventional procedures in the elderly. Our small elderly cohort was not powered enough to show a significant difference in terms of access site complications between TRA and TFA.

Systemic atherosclerotic plaque vulnerability in patients with Coronary Artery Disease with a single Whole Body FDG PET-CT scan

OBJECTIVES

Cardiovascular disease is a leading cause of morbimortality with over half cardiovascular events occurring in the asymptomatic population by traditional risk stratification. This preliminary study aimed to evaluate systemic plaque vulnerability in patients with prior Coronary Artery Disease (CAD) with a single Whole Body [FDG] PET-CT scan in terms of plaque inflammation and calcifications.

METHODS

Twenty-two patients referred for oncological evaluation and with prior history of advanced CAD or age and gender matched controls without cardiovascular disease, underwent a Whole Body PET-CT scan 90 min after injection of 18F-FDG. A total of 975 transaxial PET images were retrospectively analysed to assess plaque inflammation using a standardized method of analysis with averaged Target-to-Background Ratios (TBRs) at different levels, in the thoracic and abdominal aorta, carotids, LAD, common iliac and femoral arteries, and were correlated with calcium scores from the CT images.

RESULTS

TBRs from the thoracic aorta were higher in male patients than controls (1.49±0.11, p<0.05) and a gradient was observed (ascending > descending > aortic arch), and were also higher in the carotids in female patients (1.43±0.07) versus controls (p<0.05). A tendency for higher levels of plaque inflammation in the abdominal aorta was noted in all groups, but no significant FDG uptake was found either in the iliac or femoral arteries in any group. Plaque inflammation was also higher in the LAD in males but with large variations. Higher levels of calcifications were noted in the LAD, infra-renal abdominal aorta and common iliac arteries, but without significant correlation with plaque inflammation except sporadic overlapping.

CONCLUSION

Patients with advanced CAD are at risk for vulnerable inflamed atheromas in other territories such as the thoracic aorta and carotid arteries, underpinning the systemic nature of the atherosclerotic disease. Coexistence with calcifications is rare, suggesting a different functional status of the plaques and different stages of the disease. Evaluation of subclinical systemic plaque vulnerability in CAD with a Whole Body [FDG] PET-CT scan is feasible and a potentially useful biomarker to assess subclinical vascular risk for risk stratification and treatment optimization, but further studies are needed.

Influence of Age Ranges on Relationship of Complex Aortic Plaque With Cervicocephalic Atherosclerosis in Ischemic Stroke

BACKGROUND

Complex aortic plaque is a potential cause of acute ischemic cerebrovascular disease, which needs timely identification. Also as a marker for systemic atherosclerosis, complex aortic plaque may be indicated by significant (≥50%) cervicocephalic atherosclerotic stenosis. We aimed at examining whether age ranges would influence their association to more accurately estimate the risk of having complex aortic plaque in acute ischemic cerebrovascular disease.

METHODS

Aortic arch and cervicocephalic arteries were simultaneously evaluated using computed tomography angiography. Middle-aged (45-64 years) and old-aged (65-85 years) acute ischemic cerebrovascular disease patients were divided into 2 groups according to whether there was an aortic arch plaque with thickness of greater than or equal to 4 mm or associated ulcerations or mural thrombus.

RESULTS

Old-aged patients (n = 107) had a higher prevalence of complex aortic plaque (67.3% versus 30.9%, P < .001) than those middle aged (n = 178). Among middle-aged patients, the presence of extracranial significant atherosclerotic stenosis (adjusted odd ratio = 2.89, 95% confidence interval: 1.42-5.86) rather than intracranial ones independently predicted complex aortic plaque. Regarding the extent of significant cervicocephalic atherosclerotic stenosis, the presence of multi-segment, bilateral, simultaneous extracranial and intracranial, and simultaneous anterior and posterior circulation ones were independent indicators for complex aortic plaque in the middle-aged subgroup (adjusted odd ratio = 2.42, 2.05, 2.26, 2.14, respectively). By contrast, no statistical correlation of complex aortic plaque and significant cervicocephalic atherosclerotic stenosis was found among old-aged patients.

CONCLUSION

Considering the ranges of age was important to more precisely predict complex aortic plaque with significant cervicocephalic atherosclerotic stenosis in acute ischemic cerebrovascular disease.

Approach to concurrent coronary and carotid artery disease: Epidemiology, screening and treatment

Summary The concomitance between coronary artery disease and carotid artery disease is known and well documented. However, it is a fact that, despite the screening methods for these conditions and the advances in surgical treatment, little has been achieved in terms of reducing the risk of complications in the perioperative period. Publications are scarce, being mostly composed of reports or case series. There is little agreement on the best initial therapeutic approach (myocardial versus carotid revascularization) or the best technique to be used (surgery with or without extracorporeal circulation, hybrid treatments, etc.). The authors performed a review of the evidence in this clinical scenario, raising pragmatic questions that help in the therapeutic decision.

Association of Dietary Factors with Progression of AA in Stroke/TIA Patients

OBJECTIVE

To investigate the effect of dietary factors such as calorie intake and dietary fats on the progression of aortic arch atheroma (AA).

BACKGROUND

In stroke/TIA patients, progression of AA is associated with recurrent vascular events.

DESIGN/METHODS

Consecutive patients with measurable (>1 mm) AA atheroma on baseline transesophageal echocardiogram (TEE) evaluation consented to a protocol mandated follow-up TEE at 12 months. Patients that had adequate paired AA images were assessed for progression, defined as Δ ≥ 1 grade worsening (based on plaque thickness over 12 months). Stroke risk factors and fasting lipid profile were assessed at baseline. The patient's nutritional intake was measured at baseline using the Gladys Block Food Frequency Questionnaire.

RESULTS

One-hundred-nine patients (70 strokes, 33 TIAs) had sequential TEEs, of whom 27% (N=30) progressed and 73% (N=79) did not. Patients with progression had higher daily calorie (1778 ± 623 vs. 1378 ± 406 Calories, p=0.008), fat (76 ± 33 vs. 52 ± 23 grams, p=0.0002), carbohydrate (208 ± 78 vs. 169 ± 57 grams, p=0.01) and protein (73 ± 26 vs. 57 ± 21 grams, p=0.005) intake. On Further analysis among different fats showed a higher consumption of saturated fats (25 ± 12 vs. 17 ±8 grams, p=0.00051) as well as unsaturated fats (44 ± 20 vs. 30 ± 13 grams, p=0.002). These differences remained significant after we adjusted for the medication use. However the significance of these differences was attenuated after adjusting for the calorie intake. Cholesterol consumption did not differ between the progression and no-progression group (262 ± 125 vs. 213 ± 149 mg, p=0.2).

CONCLUSIONS/RELEVANCE

Calorie intake plays a significant role in the progression of AA. Further studies are needed to confirm these findings and determine the specific dietary modifications that may prevent AA progression and associated recurrent vascular events.

Carotid endarterectomy for critical stenosis prior to cardiac surgery: Should it be done? A retrospective cohort study

INTRODUCTION

Stroke remains a major cause of morbidity and mortality after cardiac surgery affecting 2% of patients. Extra-cranial carotid artery disease has been implicated in the aetiology of post cardiac surgery stroke. The aim of the study was to evaluate and compare the morbidity and mortality in patients undergoing cardiac surgery with or without staged carotid endarterectomy (CEA) in a tertiary referral centre.

METHODS

A 5 year retrospective study was performed. The primary endpoints were defined as peri-operative stroke and myocardial infarction (MI) with secondary outcome defined as death within 30 days of surgery.

RESULTS

In total 5924 cardiac procedures and 29 staged CEA's were performed. The rate of stroke and MI was significantly higher in patients undergoing staged CEA pre-cardiac surgery compared to patients undergoing cardiac surgery with confirmed or presumed normal carotid arteries (10.34% vs 1.43%; P = .008 and 13.79% vs 0.38%; P < .0001, respectively). There was no significant difference in the stroke and MI rate in those patients undergoing cardiac surgery with confirmed or presumed normal carotid arteries compared to those with significant carotid disease undergoing cardiac surgery with no prior carotid intervention (1.43% vs 3.16%; P > .05 and 0.38% vs 1.05%; P > .05, respectively).

CONCLUSIONS

Carotid disease is associated with an increased risk of stroke post cardiac surgery. Staged carotid intervention cannot be justified based on these results. Increased risk of stroke post cardiac surgery in patients with significant carotid disease needs to be accepted, as the risk of stroke and MI during carotid intervention pre cardiac surgery is significantly higher.

Relationship between cognitive impairment and echocardiographic parameters: a review

With >24 million people affected worldwide, dementia is one of the main public health challenges modern medicine has to face. The path leading to dementia is often long, with a wide spectrum of clinical presentations, and preceded by a long preclinical phase. Previous studies have demonstrated that clinical strokes and covert vascular lesions of the brain contribute to the risk for developing dementia. Although it is not yet known whether preventing such lesions reduces the risk for dementia, it is likely that starting preventive measures early in the course of the disease may be beneficial. Echocardiography is a widely available, relatively inexpensive, noninvasive imaging modality whereby morphologically or hemodynamically derived parameters may be integrated easily into a risk assessment model for dementia. The aim of this review is to analyze the information that has accumulated over the past two decades on the prognostic value of echocardiographic factors in cognitive impairment. The associations between cognitive impairment and echocardiographic parameters, including left ventricular systolic and diastolic indices, left atrial morphologic parameters, cardiac output, left ventricular mass, and aortic root diameter, have previously been reported. In the light of these studies, it appears that echocardiography may help further improve currently used risk assessment models by allowing detection of subclinical cardiac abnormalities associated with future cognitive impairment. However, many limitations, including methodologic heterogeneity and the observational designs of these studies, restrict the scope of these results. Further prospective studies are required before integrating echocardiography into a preventive strategy.

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.

Cardiovascular MRI in Detection and Measurement of Aortic Atheroma in Stroke/TIA patients

Background

Aortic Atheroma (AoA) is an independent risk factor for new and recurrent stroke. AoA ulceration and mobility are associated with an increased risk for brain embolism. Transesophageal echocardiography (TEE) is the gold standard for detection and measurement of AoA in stroke/TIA patients. Cardiovascular MRI (cMRI) could be an alternative, non-invasive imaging modality for stroke/TIA patients. The objective of this study was to assess the accuracy and correlation of AoA detected and measured by cMRI versus TEE in patients with recent stroke/TIA.

Methods and results

Twenty-two stroke/TIA patients undergoing TEE as a part of their stroke workup consented to a protocol-mandated cMRI performed on a 1.5 T magnet. The protocol included an axial non-breathhold EKG-gated dual-echo spin echo MRI of the thoracic aorta (TR/TE1/TE2=900/29/69) and a contrast-enhanced breathhold 3D gradient-echo image of the thorax (flip/TR/TE=12/4.0/1.71). Maximum plaque thickness, ulceration (≥ 2 mm) and mobility of AoA were assessed in the proximal (ascending and proximal arch) and distal (distal arch and descending) segments of thoracic aorta by a cardiologist to interpret the TEE and a radiologist to interpret the cMRI. There was good correlation between cMRI and TEE in measurement of plaque thickness in the proximal segments (R=0.73, p<0.0001) and the distal segments (R=0.81, p<0.0001) of the aortic arch (AA). cMRI had a high degree of accuracy in detecting measurable AoA (≥ 1 mm) in the proximal segments (sensitivity 90%, specificity 100%), as well as the distal segments (sensitivity 67%, specificity 100%). cMRI also had a high degree of accuracy in detecting significant AoA (≥ 4 mm) in proximal segments (sensitivity 71%, specificity 93%), as well as distal segments (sensitivity 71%, specificity 100%).

Conclusion

The study showed a high degree of accuracy and correlation of AoA detected and measured by cMRI as compared to TEE in patients with recent stroke/TIA. This technique has limitations in detection of AoA ulceration, and protocols assessing AoA mobility need to be developed.

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.

Hyperhomocysteinemia is Associated with Aortic Atheroma Progression in Stroke/TIA Patients

Significance: Aortic arch (AA) atheroma and AA atheroma progression are independent risk factors for recurrent vascular events in stroke/transient ischemic attack (TIA) patients. Total homocysteine level (tHcy) is an independent risk marker for atherosclerosis including that found in AA. The purpose of this study was to prospectively test the association between AA atheroma progression and tHcy. Methods: This is a cohort study of 307 consecutive hospitalized stroke/TIA patients undergoing transesophageal echocardiogram (TEE) as a part of their clinical workup. Measurable AA atheroma was detected in 167 patients of whom 125 consented to a protocol-mandated follow-up TEE at 12 months. Patients had evaluation for vascular risk factors, dietary factors (folate, B12 and pyridoxine), and methylene tetrahydrofolate reductase (MTHFR) polymorphism. One hundred eighteen stroke/TIA patients had tHcy, acceptable paired AA images, and detailed plaque measurements. An increase by ≥1 grade of AA atheroma was defined as progression. Results: Of the 118 patients, 33 (28%) showed progression and 17 (14%) showed regression of their index arch lesion at 1 year. tHcy (≥14.0 μmol/l) was significantly associated with progression on both univariate (RR = 3.4, 95% CI 2.0–5.8) and multivariate analyses (adjusted RR = 3.6, 95% CI 2.2–4.6). The changes in AA plaque thickness (r² = 0.11; p < 0.001) and AA plaque area (r² = 0.08; p = 0.002) correlated with tHcy. tHcy was associated with change in plaque thickness over 12 months, independent of age, dietary factors, renal function and MTHFR polymorphism (Standardized β-coefficient 0.335, p = 0.02). Conclusions: Our results validate the association and a linear correlation between tHcy and progression of AA atheroma.

Atherothrombosis and plaque heterology: different location or a unique disease?

Formation of unstable plaques frequently results in atherothrombosis, the major cause for ischaemic stroke, myocardial infarction and peripheral arterial disease. Patients who have symptomatic thrombosis in one vascular bed are at increased risk of disease in other beds. However, the development of the disease in carotid, coronary and peripheral arteries may have different pathophysiology suggesting that more complex treatment protocols may have to be designed to reduce plaque development at different locations. In this review we describe the known risk factors, compare the developmental features of coronary and carotid plaque development and determine their association with end-point ischaemic events. Differences are also seen in the genetic contribution to plaque development as well as in the deregulation of gene and protein expression and cellular signal transduction activity of active cells in regions susceptible to thrombosis. Differences between carotid and coronary artery plaque development might help to explain the differences in anatomopathological appearance and risk of rupture.

Association of Leukocyte Count With Progression of Aortic Atheroma in Stroke/Transient Ischemic Attack Patients

Background and Purpose— Leukocyte count is an independent predictor of stroke. We investigated the association between leukocyte count and progression of aortic atheroma over 12 months in stroke/transient ischemic attack (TIA) patients.

Methods— Consecutive ischemic stroke and transient ischemic attack patients underwent 12-month sequential transesophageal echocardiography and were assessed for total and differential leukocyte counts on admission. Paired aortic plaque images were assessed for several parameters, including changes in grade, intimal-medial thickness (IMT), and cross-sectional area. Multivariate linear and logistic regressions were used to calculate the effect of leukocyte count on the change in aortic atheromas over 12 months.

Results— Of the 115 participants (mean±SD age, 64.6±11.9 years; 53.1% men; 73.4% white, 24.2% black, and 2.3% Asian), 45 (35%) showed clinically significant progression of aortic atheromas (maximal change in IMT >0.70 mm over 12 months). The mean admission leukocyte count was higher in the progression group compared with the no-progression group (8.6±2.2 vs 7.3±2.2×10 9 /L respectively, P =0.002). Each unit increase in leukocyte count was associated with a 0.26-mm increase in aortic arch IMT over 12 months ( P =0.006). After adjustment for other atherosclerosis risk factors, the relation persisted (mean increase in aortic arch IMT per unit increase in leukocyte count=0.27 mm, P =0.007). Each unit increase in leukocyte count was associated with an increased risk of significant progression of aortic atheromas (adjusted odds ratio=1.33; 95% CI, 1.09 to 1.61).

Conclusions— In stroke/transient ischemic attack patients, leukocyte count is independently associated with the progression of aortic atheroma over 12 months (>0.70 mm), which is associated with cardiovascular risk.

Aortic Arch Atheroma Progression and Recurrent Vascular Events in Patients With Stroke or Transient Ischemic Attack

Background— It is not known whether progression of aortic arch (AA) atheroma is associated with vascular events in patients with stroke or transient ischemic attack (TIA).

Methods and Results— AA atheroma was detected on baseline transesophageal echocardiogram in 167 consecutive patients who had prevalent stroke or TIA. Of these, 125 consented to a follow-up transesophageal echocardiogram at 12 months. Adequate paired AA images were obtained in 117 (78 with strokes, 39 with TIAs), which allowed detailed measurements of plaques. On admission for their index stroke or TIA, patients were assessed for stroke risk factors, stroke subtypes, baseline AA plaque characteristics, and laboratory parameters. Progression of AA atheroma was observed in 33 patients (28%) on 12-month follow-up transesophageal echocardiogram. It was determined that the progression group had significantly higher adjusted homocysteine levels ( P <0.0001) and neutrophil counts ( P <0.0001) than the no-progression group. These patients were followed up for a median of 1.7 years from the index stroke/TIA (range 0.5 to 4.5 years) for vascular events including stroke, TIA, myocardial infarction, and death due to vascular causes. Kaplan-Meier curves showed fewer patients with AA atheroma progression remained free of the composite vascular end point (49% compared with 89% in the no-progression group; P <0.0001). AA atheroma progression was associated with composite vascular events (hazard ratio 5.8, 95% confidence interval 2.3 to 14.5, P =0.0002) after adjustment for a propensity score based on confounders.

Conclusions— In this preliminary study of stroke/TIA patients with AA atheroma on transesophageal echocardiogram, AA atheroma progression was associated with recurrent vascular events.

Baroreflex Sensitivity Is Impaired in Bilateral Carotid Atherosclerosis

BACKGROUND AND PURPOSE

The arterial baroreflex is an important determinant of the short-term regulation of blood pressure and cardiovascular variability. The purpose of our study was to determine whether baroreflex sensitivity (BRS) and heart rate (HR) variability are altered in patients with carotid atherosclerosis (CA) and to assess the impact of characteristics of CA on BRS.

METHODS

BRS and HR variability were prospectively evaluated in 75 consecutive patients undergoing carotid duplex examination in our neurosonology unit. Resting BRS was measured with the sequence method. HR variability was evaluated using spectral analysis.

RESULTS

BRS was significantly reduced in patients with bilateral CA compared with patients without CA (P=0.015) and patients with unilateral CA (P=0.045). BRS was unaltered in patients with unilateral CA compared with patients with no CA. BRS was already reduced in mild (stenosis <50%), bilateral CA and was not further impaired in more severe CA. The association of BRS impairment with bilateral CA remained significant after adjustment for age, hypertension, and a history of stroke or transient ischemic attack. The study of HR variability demonstrated a reduction in the power of high-frequency band in patients with bilateral CA compared with patients with unilateral CA or without CA (P=0.015).

CONCLUSIONS

Bilateral CA is associated with an impairment of BRS and a shift of the sympathovagal balance toward a relative decrease of the parasympathetic component of HR variability. These changes are already present in mild, bilateral CA.

Neuroimaging and cardiac correlates of cognitive function among patients with cardiac disease

In the present study, we examined the relationships between whole brain volume (WBV), subcortical hyperintensities (SH), indices of cardiac disease and cognitive function in nondemented cardiac patients with evidence of mild cerebrovascular disease. A total of 27 individuals with evidence of cardiac disease underwent neuropsychological examination, neuroimaging, and cardiac assessment. Cognition was assessed with the Dementia Rating Scale-2 (DRS). WBV and SH were quantified using a semi-automated thresholding program based on MRI. Correlational analyses revealed that WBV predicted performance on the overall DRS score, the attention subscale and the initiation/perseveration scale. SH were significantly associated with performance on the attention subscale, and the initiation/perseveration subscale. Regression analyses revealed that SH accounted for most of the variance in the initiation/perseveration scale, whereas WBV accounted for most of the variance in the attention scale. The only cardiac structural or functional variable related to the neurological indices was aortic diameter, which was strongly related to both neuroimaging variables, as well as performances on the DRS attention and initiation/perseveration subscales. Our results highlight the importance of overall brain parenchyma in determining cognitive status among patients at risk for cognitive decline and suggest that select indices of structural cardiac morphology may be related to the early phases of cerebrovascular disease and cognitive status.

Treatable Potential Cardiac Sources of Embolism in Patients with Cerebral Ischemic Events: A Selective Transesophageal Echocardiographic Study

OBJECTIVES

To characterize cardiac sources of emboli detected by transesophageal echocardiography (TEE) in patients without recognizable cause of transient ischemic attack (TIA) and/or ischemic stroke and TIA.

METHODS

We examined a prospective registry that included all patients with TIA and/or stroke evaluated by TEE between July 2000 and August 2001 at our medical center. Ischemic events were classified according to clinical and neuroimaging findings as cortical, lacunar, or vertebrobasilar circulation. Demographic, clinical, neuroimaging, and echocardiographic characteristics were studied.

RESULTS

TEE was performed in 237 patients without recognized cause of TIA and/or stroke, of which 105 (44%) events were cortical, 35 (15%) were lacunar, 32 (14%) were vertebrobasilar, and 65 (27%) were in multiple distributions. Mean age of patients was 59 +/- 14 years (range, 21 to 93 years); 119 (51%) were men. Potential treatable cardioembolic sources were detected in 146 (61%) patients: patent foramen ovale with right-to-left shunt (n = 59), left atrial clot (n = 6), left atrial appendage clot (n = 8), and severe thoracic aortic atherosclerotic plaque disease (plaque thickness >4 mm) (n = 79 patients [33%], 56 had an ulcerated plaque and 4 had mobile plaque). Patient age and topography of the ischemic event did not correlate with TEE-defined cardioembolic sources.

CONCLUSIONS

TEE identified high frequencies of potential treatable cardioembolic sources in patients with ischemic events. TEE should be considered in all patients who do not have identified cause of TIA and/or stroke for early treatment and prevention of recurrent events.

Atherosclerosis of the aorta: Risk factor, risk marker, or innocent bystander?

OBJECTIVES

The goal of this study was to investigate whether complex aortic atherosclerosis is associated with increased risk of vascular events in a non-selected population.

BACKGROUND

In selected high-risk patients, aortic atherosclerosis is associated with increased risk of vascular events.

METHODS

We describe the relationship between simple versus complex (>4-mm thick or mobile debris) aortic atherosclerotic plaques and vascular events during follow-up in a random sample of 585 persons (age > or =45 years) using 1993 to 2000 data from the Stroke Prevention: Assessment of Risk in a Community (SPARC), a prospective population-based longitudinal study.

RESULTS

At five-year median follow-up (range, 0.5 to 6.5 years), cardiac events (death, non-fatal myocardial infarction, coronary revascularization, heart failure associated with coronary artery disease) and cerebrovascular events (ischemic fatal and non-fatal strokes, transient ischemic attacks) had occurred in 95 subjects and 41 subjects, respectively. Age, male gender, prior coronary artery disease, higher pulse pressure, and diabetes were significant cardiovascular predictors. Age, prior myocardial infarction, and a history of atrial fibrillation were significant cerebrovascular predictors. Simple aortic plaques (253 persons) were not independently associated with either cardiac or cerebrovascular events. Complex plaques (44 persons) were marginally associated with cardiac events, adjusting for age and gender (hazard ratio [HR], 2.28; 95% confidence interval [CI], 1.11 to 4.68; p = 0.053 for two degrees of freedom [complex and simple plaques vs. no plaques]) but not after adjusting for additional clinical risk factors (HR, 1.22; 95% CI, 0.57 to 2.62; p = 0.64). Complex plaques were associated with cerebrovascular events only univariately.

CONCLUSIONS

Aortic atherosclerotic plaques are not associated with future cardiac or cerebrovascular events. Aortic atherosclerosis may not be an independent risk factor for vascular events in the general population.

Changes in cardiac thrombus status after cerebral ischemia

BACKGROUND AND PURPOSE

Intracardiac thrombi are a potential source of cerebral embolism. The disposition of intracardiac thrombi in ischemic stroke/transient ischemic attack (TIA) patients was investigated over a 10-month period using omniplanar transesophageal echocardiography (TEE).

METHODS

One hundred and five patients underwent TEE examination at <1 month and again at 9-12 months (mean 10 months) after symptom onset. TEEs were evaluated for thrombi in the left atrium, left atrial appendage and left ventricle. Stroke risk factors and TEE findings were compared between patients with and without new thrombi on follow-up TEE. Similar comparisons were made in patients with and without disappearance of thrombi on the follow-up TEE. The effect of anticoagulants was evaluated.

RESULTS

Intracardiac thrombi were found initially in 18% (95% CI 11-25%) of patients in 79% (95% CI 61-97%) of whom the thrombi disappeared on the follow-up TEE; this significantly correlated with warfarin anticoagulation (p = 0.037). In the remainder 82% (95% CI 75-89%) patients, new thrombi were detected on the follow-up TEE in 8% (2-14%). These were older (p = 0.009), and not on anticoagulation. Patients with aortic atheroma >/=4 mm were also more likely to develop new intracardiac thrombi (p = 0.001).

CONCLUSIONS

Anticoagulation with warfarin for 10 months is associated with conditions leading to disappearance of intracardiac thrombi after a cerebral ischemic event and hence has a probable therapeutic role. Older patients, not anticoagulated, and those with significant aortic atheroma >/=4 mm may have increased probability for de novo thrombus development. These patients may be at risk of cardiac embolization and could be considered for prophylactic anticoagulation.

Cardiac baroreceptor sensitivity predicts long-term outcome after acute ischemic stroke

BACKGROUND AND PURPOSE

The baroreceptor reflex arc is important in the short-term regulation of the cardiovascular system, and small studies have reported impaired cardiac baroreceptor sensitivity (BRS) after acute stroke. However, the prognostic significance of impaired BRS is uncertain.

METHODS

One hundred twenty-four patients underwent simultaneous ECG and noninvasive beat-to-beat blood pressure (BP) monitoring within 72 hours of neuroradiologically confirmed acute ischemic stroke. Cardiac BRS was assessed from the combined alpha-index by means of power spectral analysis techniques. Baseline data for acute stroke patients were compared with those of a control group matched for age, sex, and casual BP. Patients were followed up for a median of 1508 days (range, 9 to 2656 days), and outcome was compared between patients with and without impaired BRS.

RESULTS

Median BRS values were significantly lower in stroke patients than in controls (5 [interquartile range, 3.5 to 7.4] versus 6.2 [interquartile range, 4.5 to 8.3] ms/mm Hg; P=0.04). Sixty-one (33 male) patients (mean age, 70.2 [SD 10.5] years) had impaired BRS (< or =5.0 ms/mm Hg) compared with 63 (35 male) patients (mean age, 70.6 [SD 11.7] years) without impaired BRS (>5.0 ms/mm Hg). Stroke patients with impaired BRS values had a significantly poorer prognosis (28% versus 8% mortality rate during the follow-up period) although there were no differences in age, stroke severity, stroke type, or casual or 24-hour BP parameters between the 2 groups.

CONCLUSIONS

Impaired cardiac BRS is associated with increased long-term mortality after acute ischemic stroke, irrespective of age, sex, stroke type, and BP. This may reflect cardiac arrhythmias, but the mechanisms underlying this association are unknown, although therapies that improve cardiac BRS after stroke warrant further investigation.

Cardioembolic stroke: an update

Embolism of cardiac origin accounts for about one fifth of ischaemic strokes. Strokes due to cardioembolism are in general severe and prone to early recurrence. The risk of long term recurrence and mortality are high after a cardioembolic stroke. Cardioembolism can be reliably predicted on clinical grounds but is difficult to document. MRI, transcranial doppler, echocardiogram, Holter monitoring, and electrophysiological studies increase our ability to identify the source of cardioembolism. Non-valvular atrial fibrillation is the commonest cause of cardioembolic stroke. Despite its enormous preventive potential, continuous oral anticoagulation is prescribed for less than half of patients with atrial fibrillation who have risk factors for cardioembolism and no contraindications for anticoagulation. Alternatives to oral anticoagulation in this setting include safer and easier to use antithrombotic drugs and definitive treatment of atrial fibrillation. Available evidence does not support routine immediate anticoagulation of acute cardioembolic stroke.

Risk factors for progression of aortic atheroma in stroke and transient ischemic attack patients

BACKGROUND AND PURPOSE

Aortic atheroma is an independent risk factor for stroke and undergoes temporal progression. Clinical and risk factor associations of such progression are unknown. Hyperhomocysteinemia has been linked with atherosclerosis, including that in the cerebral vasculature. This study investigated associations between elevated homocysteine levels and other stroke vascular risk factors and the risk of aortic atheroma progression in patients with cerebrovascular disease.

METHODS

Fifty-seven stroke and 21 transient ischemic attack patients underwent multiplanar transesophageal echocardiograms within 1 month of symptom onset and again at 9 months. Aortic atheroma was graded and stratified by use of existing criteria. Stroke risk factors; use of anticoagulant, antiplatelet, and hypolipidemic drugs; and clinical and etiological subtypes of stroke were recorded and compared in patients stratified for the presence or absence of aortic atheroma progression.

RESULTS

Of the 78, 29 (37%) progressed, 32 (41%) remained unchanged, and 17 (22%) regressed. Progression was most marked at the aortic arch (P=0.005), followed by the ascending segment (P<0.04). In nearly two thirds of the patients in whom aortic atheroma remained unchanged over 9 months, no atheroma was evident on baseline transesophageal echocardiogram. Only homocysteine levels > or =14.0 micromol/L (P=0.02), total anterior cerebral infarct (P=0.02), and large-artery atherosclerosis (P=0.005) significantly correlated with progression.

CONCLUSIONS

Among vascular risk factors, elevated homocysteine levels are associated with aortic atheroma progression. Stroke and transient ischemic attack patients with aortic atheroma should undergo assessment of homocysteine levels, which, if elevated, may be treated with vitamins in an effort to arrest aortic atheroma progression.