Valvular strands and cerebral ischemia. Effect of demographics and strand characteristics

BACKGROUND AND PURPOSE

Valvular strands, thin filamentous material attached to the mitral or aortic valve, are seen during transesophageal echocardiography and have been associated with stroke. Little is known about this association in different age, sex, and race-ethnic subgroups and the effect of various strand characteristics on this association.

METHODS

From patients referred for transesophageal echocardiography, 73 patients with recent ischemic stroke (68) or transient ischemic attack (5) were age matched to 73 stroke- and transient ischemic attack-free control subjects. The association between valvular strands and cerebral ischemia was evaluated for the overall group and demographic subgroups. The effect of strand location, length, number, and valve thickness was also determined.

RESULTS

An association between cerebral ischemia and valvular strands was observed (odds ratio [OR] = 4.4; 95% confidence interval [CI] = 2.0 to 9.6). The association was found for both men and women and among all three race-ethnic groups. The OR was greater in those who were younger (12.5 [95% CI = 2.4 to 64.5] for age < 60, 4.8 [95% CI = 1.3 to 18.2] for age 60 to 69, and 1.8 [95% CI = 0.5 to 6.4] for age > or = 70 years). Strands on both the mitral (OR = 3.5; 95% CI = 1.5 to 7.9) and aortic (OR = 3.7; 95% CI = 1.1 to 11.9) valve were associated with cerebral ischemia, whereas the number and length of strands were not. The effect of strands was independent of mitral or aortic valve thickness.

CONCLUSIONS

Valvular strands, whether mitral or aortic, are associated with ischemic stroke, especially among younger persons.

Subarachnoid hemorrhage in the African-American population: a cooperative study

The clinical outcome of patients following subarachnoid hemorrhage is complicated by delayed cerebral ischemia and contributing factors such as hypertension. To observe the impact of hypertension and delayed cerebral ischemia on the outcome of a predominantly African-American cohort following subarachnoid hemorrhage, both retrospective (n = 42) and prospective (n = 21) studies were conducted. In the total pool (n = 63), the mean age was 49.7 years (range: 17 to 80) with a preponderance of female patients (70%). Aneurysm formation was significant in the region of the posterior communicating artery. Of the patients reviewed, 73.8% had preexisting hypertension and 45.9% developed delayed cerebral ischemia. Approximately 89% of the patients who suffered from delayed cerebral ischemia had hypertension. Results failed to display any significant beneficial association between the use of the calcium channel blocker nimodipine and delayed cerebral ischemia. Use of the antifibrinolytic drug aminocaproic acid demonstrated a worse patient outcome. It is not recommended that aminocaproic acid be used in this population. Subsequently, due to the proportional occurrence of delayed cerebral ischemia in hypertensive patients following subarachnoid hemorrhage, it is suggested that prophylactic surgical management of unruptured intracranial aneurysms be considered in hypertensive patients. Further study is needed to discern the association between hypertension, delayed cerebral ischemia, and stroke in patients following subarachnoid hemorrhage.

Cerebrovascular disease in the Afro-American population

The types of stroke which are unique to Afro-American patients are reviewed. The major risk factors which contribute to the higher incidence of stroke in this population are analyzed.

Traditional risk factors and ischemic stroke in young adults: the Baltimore-Washington Cooperative Young Stroke Study

OBJECTIVE

To determine the association of hypertension, diabetes, and cigarette smoking with incidence of ischemic stroke in young adults.

DESIGN

Case-control study.

SETTING

Population-based sample of cases and controls.

SUBJECTS

The study included 296 cases of incident ischemic stroke among black and white adults aged 18 to 44 years in central Maryland counties from the Baltimore-Washington Cooperative Young Stroke Study and 1220 black and white adults aged 18 to 44 years from the Maryland Behavioral Risk Factor Survey, a telephone survey of a random sample of the same region, to serve as controls.

MAIN OUTCOME MEASURES

Logistic regression models were developed to determine the age-adjusted odds ratios for each risk factor. Population-attributable risk percent were computed based on the odds ratios and prevalence of each risk factor.

RESULTS

The age-adjusted odds ratios (95% confidence intervals) for white men (WM), white women (WW), black men (BM), and black women (BW) were as follows: current cigarette smoking: WM, 2.0 (1.1-3.8), WW, 2.1 (1.1-4.3), BM, 3.3 (1.6-6.6), and BW, 2.2 (1.3-3.9); history of diabetes mellitus: WM, 22.9 (5.8-89.6), WW, 6.2 (1.9-20.2), BM, 4.2 (0.8-21.9), and BW, 3.3 (1.4-7.7); and history of hypertension: WM, 1.6 (0.7-3.2), WW, 2.5 (1.1-5.9), BM, 3.8 (1.8-7.9), and BW, 4.2 (2.4-7.5). The population-attributable risk percent (95% confidence intervals) were as follows: current cigarette smoking: WM, 22.6 (3.1-38.2), WW, 17.2 (4.0-34.0), BM, 40.5 (23.1-54.0), and BW, 29.1 (13.5-41.9); history of diabetes mellitus: WM, 19.0 (8.2-28.5), WW, 15.8 (3.8-26.3), BM, 13.2 (5.3-20.4), and BW, 22.1 (12.5-30.7); and history of hypertension: WM, 21.7 (6.2-34.6), WW, 21.3 (5.4-34.5), BM, 53.5 (39.0-64.4), and BW, 50.5 (37.1-61.1).

CONCLUSIONS

Hypertension, diabetes mellitus, and current cigarette smoking are important risk factors in a biracial young adult population. Cigarette smoking and hypertension, the 2 most modifiable risk factors, were particularly important risk factors in young blacks.

Aortic atheromas and acute ischemic stroke: a transesophageal echocardiographic study in an ethnically mixed population

PURPOSE

Proximal aortic atheromas have been suggested as a potential ischemic stroke determinant in the elderly, especially in cases of unexplained (cryptogenic) stroke. Our aim was to assess the potential role of proximal aortic atheromas as an independent risk factor for stroke by comparing their frequency in patients with acute ischemic stroke and in stroke-free control subjects. The frequency of atheromas was also compared among different ethnic groups.

PATIENTS AND METHODS

A case-control study was conducted in 106 patients with acute ischemic stroke and 114 stroke-free control subjects. The presence of atheromas of the proximal portion of the aorta was assessed by biplane transesophageal echocardiography. Atheromas were categorized on the basis of their thickness (0.2 to 0.4 cm, small; > or = 0.5 cm, large) and complexity (i.e., ulceration or mobility). The association between aortic atheromas and ischemic stroke was tested, controlling for patients' demographic variables and stroke risk factors. In stroke patients, subgroup analyses were performed to test the associations between aortic atheromas and stroke diagnostic subtypes (determined cause versus cryptogenic) and presence and degree of carotid stenoses by duplex Doppler examination.

RESULTS

The frequency of large aortic atheromas was greater in stroke patients than in controls (26% versus 13%; crude odds ratio [OR] 2.4, 95% CI 1.2 to 4.7); ulcerated or mobile atheromas also tended to be more frequent in stroke patients (12% versus 5%; OR 2.5, 95% CI 1.0 to 6.8). Differences were entirely attributable to the subgroup of patients aged 60 years or older, in whom the frequency of ulcerated or mobile atheromas was particularly high among cryptogenic stroke patients (22% versus 8% in control subjects; OR 3.4, 95% CI 1.1 to 11.2). Multivariate analysis showed the presence of large atheromas to be independently associated with stroke in the entire study group (adjusted OR 2.6, 95% CI 1.1 to 5.9) and in the older subgroup (OR 2.4, 95% CI 1.1 to 5.7). Carotid stenosis > or = 60% was more frequent with increasing size and complexity of aortic atheromas but had low predictive value (16%) for presence of large atheromas; moreover, 36% of patients with mild or no carotid stenosis had large or complex aortic atheromas. No significant differences were found in the frequency of atheromas by ethnic group.

CONCLUSIONS

Proximal aortic atheromas > or = 0.5 cm in size are a risk factor for ischemic stroke in patients aged 60 years or older. Ulcerated or mobile atheromas may play a role in explaining some cryptogenic strokes in the elderly. The risk for stroke of patients with aortic atheromas may be similar across different ethnic groups. The absence of carotid stenosis does not exclude aortic atheromas as a potential cause for ischemic stroke.

Impact of race and ethnicity on ischemic stroke. The University of California at San Diego Stroke Data Bank

BACKGROUND AND PURPOSE

As the US minority population continues to grow, increasing numbers of nonwhite citizens are at risk for stroke. A better understanding of how ischemic stroke differs in the minority populations may lead to more effective clinical management.

METHODS

We prospectively evaluated 542 consecutive patients (416 whites, 71 Mexican Americans, 55 blacks) presenting to the University of California at San Diego Medical Center or the San Diego Veterans Affairs Hospital with presumed acute ischemic stroke or transient ischemic attack.

RESULTS

Whites had a higher proportion of transient ischemic attacks (32% versus 18% and 17% for blacks and Mexican Americans, respectively) and had the lowest prevalence of diabetes mellitus (17% versus 29% and 40% for blacks and Mexican Americans, respectively). Mexican Americans had higher initial serum glucose levels (178 versus 133 and 131 mg/dL for whites and blacks, respectively). Blacks were youngest (average age, 56 years). There were no differences among the groups in the prevalence of prior stroke, hypertension, myocardial infarction, or smoking; initial systolic blood pressure, serum cholesterol levels, and functional deficit also were similar. Although it did not reach statistical significance, there was a trend toward relatively late presentation in the black stroke subpopulation: only 53% of blacks (compared with 73% of both Mexican Americans and whites) reached medical attention within 24 hours of stroke onset. All groups had similar diagnostic evaluations and functional outcome at 1 week. With the exception of a higher frequency of stroke of unknown cause in Hispanics, the distributions of stroke etiologies did not differ significantly among the groups.

CONCLUSIONS

These data suggest that there are significant clinical differences in populations with ischemic stroke and transient ischemic attack that are related to race and ethnic origin, but in our population these differences did not include the extent of diagnostic evaluation undertaken or stroke severity.

Racial variations in the rates of carotid angiography and endarterectomy in patients with stroke and transient ischemic attack

BACKGROUND

Carotid endarterectomy is emerging as the treatment of choice for patients with symptomatic carotid artery stenosis at low operative risk. We sought to determine if racial variations in the rate of carotid angiography and endarterectomy exist in the Veteran Affairs health care system among patients who are insulated from the cost of their care.

METHODS

From a national database of all hospitalizations at Veterans Affairs medical centers, we identified a cohort of patients with diagnoses of stroke or transient ischemic attack who were likely to be candidates for carotid angiography and endarterectomy. We used logistic regression to determine if the patient's race was associated with receiving carotid angiography and endarterectomy, after adjusting for patient's age, degree of eligibility for Veterans Affairs care, socioeconomic status, comorbidities associated with hospital admission, and geographic region of the hospital.

RESULTS

Of the 35 922 veterans in the cohort, 3535 (9.8%) underwent angiography during the study period and 1249 (3.5%) had carotid endarterectomy. Blacks constituted 18.2% of the patients with a history of stroke or transient ischemic attack, 9.8% of the patients having angiography, but only 4.2% of the patients undergoing carotid endarterectomy. Whites constituted 77.1% of the patients with a history of stroke or transient ischemic attack, 86.1% of the patients receiving angiography, and 93.0% of those having carotid endarterectomies. After adjusting for confounding variables, black patients continued to have a significantly lower likelihood than white patients of undergoing angiography (risk ratio = 0.47; 95% confidence interval = 0.42, 0.53) and subsequent endarterectomy (risk ratio = 0.28; 95% confidence interval = 0.20, 0.38).

CONCLUSIONS

Socioeconomic status and access to care within a large managed health care system do not fully explain racial differences in the rate of carotid angiography and endarterectomy. Either referral bias for evaluation for carotid endarterectomy or racial differences in the extent and location of cerebrovascular disease are more important explanations for the observed racial variations.

Pentoxifylline in the treatment of acute ischaemic stroke--a reappraisal in Chinese stroke patients

A double-blind, randomized and placebo-controlled trial was conducted on 110 Chinese patients with ischaemic stroke who were stratified into 2 subtypes (cortical and lacunar infarcts) according to their clinical and CT findings. Treatment was started within 36-48 hours after the stroke onset. Pentoxifylline was administered intravenously in a dose of 600 mg daily for 5 days, together with oral aspirin 150 mg daily. Neurological deficits were scored on admission and at one week. Demographic data were comparable between the treatment and placebo groups. For cortical infarcts, there were significantly more patients in the placebo group who deteriorated and died than in the treatment group (p < 0.02). As for the lacunar infarcts, there was no difference between groups in the numbers of patients who improved or deteriorated. Our study shows that the positive effect of pentoxifylline can be demonstrated only in patients with cortical infarction. Early deterioration and mortality were significantly decreased in these patients. The clinical course of lacunar infarction was not affected by pentoxifylline. It is not clear whether aspirin may potentiate the antiplatelet function of pentoxifylline and contribute to its temporary clinical efficacy in this way.

Racial variations in ischemic stroke-related physical and functional impairments

BACKGROUND AND PURPOSE

We sought to determine whether there are racial differences in physical and functional impairments resulting from an initial ischemic stroke.

METHODS

We conducted a prospective, county-wide, multisite cohort study including a university hospital, a community hospital, and a Veterans Affairs hospital. The study population was an inception cohort of 145 patients hospitalized for ischemic stroke. Physical and functional impairments were measured using a modified form of the Fugl-Meyer test and the Barthel Index, respectively. Nurses trained to use these tests made assessments at admission and 5, 30, 90, and 180 days after admission. Patient and disease-specific data along with treatment data and vital status were collected.

RESULTS

Forty-one patients (28%) were black. Compared with whites, black stroke patients were more likely to be widowed (51% versus 26%) and hypertensive (83% versus 63%) but less likely to be male (42% versus 69%) and alert on admission (66% versus 76%). There were no racial differences in mortality. Physical impairment was significantly more severe in black than in white patients at admission, and although physical impairment improved, it remained significantly worse in blacks. Functional impairment was also greater in black patients initially but was similar to that in white patients 90 days after the event. Multivariable analyses confirmed these findings.

CONCLUSIONS

These results indicate that blacks may have greater residual physical deficits from stroke than whites.

Pattern and ethnic variations in stroke in Saudi Arabia

We report our observations in 427 stroke patients (305 Saudis, 122 non-Saudis with an age range of 14 months to 85 years) seen in a tertiary hospital in the eastern province of Saudi Arabia over an 8-year period. Of these patients, 115 (27%) were between 18 and 45 years old, and constituted the "young stroke patients" for this study. The hospital frequency for the young was 5/10,000 inpatients. In general, there was a male preponderance, with a male:female ratio of 2.2:1 and 7:1 for Saudis and non-Saudis, respectively. Ischemic stroke (55%) was more frequent than hemorrhagic stroke (25%), and the stroke was unspecified in 20%. The main etiologic factors were hypertension, diabetes mellitus and cardiac disorders. In the young population, the frequencies of hemorrhagic and ischemic strokes were similar. In this group, the main causes of intracerebral hemorrhage were aneurysms and arteriovenous malformations, while arteriosclerosis and embolism of cardiac origin were responsible for the ischemic strokes. In Saudis, the stroke types were 59% ischemic, and 17% hemorrhagic, as against 45 and 48% in non-Saudis, respectively. Most ischemic strokes were found in Saudis (78%). Intracerebral hemorrhage accounted for 63% of all hemorrhagic strokes, and was more frequent in Saudis but subarachnoid hemorrhage was three times more common in non-Saudis. In the young stroke patients, interethnic comparison showed that individuals from the Far East were nine times more likely to have hemorrhagic than ischemic stroke compared to the others (odd's ratio = 8.7), and the etiology of ischemic stroke remained undetermined in 67% of those from the Indian subcontinent.(ABSTRACT TRUNCATED AT 250 WORDS)

Case-control study of completed ischemic stroke in the Parsis of Bombay: a population-based study

All eligible adult cases of completed ischemic stroke (N = 112) derived from a prevalence survey of the Parsi community in Bombay, India, served as the basis of a case-control study of risk factors. The stroke morbidity rate in this group was similar to that reported for North America. A control subject free of stroke was selected randomly from the same population and matched to each case by age and sex. Information was obtained on various risk factors. Hypertension, both by history (odds ratio = 10.8) and by examination (odds ratio = 2.1), had a statistically significant association with stroke (p less than 0.01). This is one of the first community-based case-control studies of stroke in a large developing country.