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J F Toole

Publications and source records attributed to J F Toole.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of multicenter study designs for investigation of carotid endarterectomy efficacy.

BACKGROUND: Our report summarizes and compares the characteristics of six prospective, multicenter, randomized clinical trials of carotid endarterectomy underway in North America and Europe. SUMMARY OF REVIEW: Three trials are designed to evaluate the safety and efficacy of endarterectomy in patients with asymptomatic carotid artery stenosis. The other three trials enroll patients who have had transient ischemic attacks or a minor cerebral infarction in the distribution of the randomized artery. Considered together, these six clinical trials span the range of candidates for carotid endarterectomy. The inclusion and exclusion criteria, methodology, and statistical considerations of each study are detailed in tables. CONCLUSIONS: The results from these trials will be helpful in resolving some of the questions surrounding endarterectomy, provided the similarities and differences in the study designs are considered when interpreting the results.

Carotid Arteries↗
PubMed1991

The community hospital-based stroke programs in North Carolina, Oregon and New York--V. Stroke diagnosis: factors influencing the diagnostic evaluation of patients following acute stroke.

Among the 4129 patients of the Community Hospital-based Stroke Program, 30% had an unspecified stroke diagnosis. Since specific diagnosis and, perhaps, eventual treatment, derives in part from diagnostic testing, we examined the effect of clinical condition, geographic and demographic factors on the incidence of certain diagnostic tests after acute stroke. In this multivariable analysis, race, sex, history of hypertension and history of diabetes did not influence the chance of having any test, but older age strongly reduced the chances of receiving extensive evaluation. When CT scanning was available, the utilization of a CT as well as other diagnostic studies including cerebral angiography, radionuclide brain scan, EEG and EKG was increased. The odds of receiving a CT scan increased if the patient was married, and decreased with a history of previous stroke. A history of previous TIA increased the chance of having a cerebral angiogram while a history of cardiac disease decreased the chance. There were striking regional geographic differences in the use of CT, radionuclide brain scanning and cerebral angiography which may, in part, reflect differences between the availability of these technologies in urban and rural hospitals. These results indicate that evaluation of stroke patients remains heterogenous.

Aged↗
PubMed1991

The Willis lecture: transient ischemic attacks, scientific method, and new realities.

First described by Thomas Willis in 1679 and defined in the 1950s, transient ischemic attack is universally agreed to be an episode of focal neurologic deficit in a vascular distribution, sudden in onset and resolving without residual deficit in less than or equal to 24 hours. Transient ischemic attack is diagnosed by characteristic history and absence of residua on neurologic examination. After these criteria had been accepted, regional cerebral blood flow and computed cranial tomography in the 1970s, later positron emission tomography, and even more recently, magnetic resonance imaging reveal prolonged pathophysiologic and metabolic disturbances even in persons with all the definitional characteristics of transient ischemic attack. These persistent abnormalities necessitate reexamination of the validity of the concept of transient ischemic attack. Furthermore, our group suspects that transient ischemic attack is probably only a marker, and not itself the risk factor, for the cerebral infarction which frequently follows transient ischemic attack. Additionally, the surprising frequency with which cerebral infarction, unrecognized by patient or physician, is revealed using neuroimaging techniques has created a need to redefine the categories heretofore used for diagnosis and assessment of therapy and prognosis for transient ischemic attack and cerebral infarction.

Algorithms↗
PubMed1991

Selection process for surgeons in the Asymptomatic Carotid Atherosclerosis Study.

BACKGROUND AND PURPOSE: The Asymptomatic Carotid Atherosclerosis Study is a prospective, multicenter, randomized clinical trial of carotid endarterectomy for the treatment of asymptomatic hemodynamically significant stenosis. This report describes the selection process for participating surgeons in the trial. METHODS: The Surgical Management Committee established guidelines for minimal annual experience and maximum neurological morbidity and mortality for surgeons to qualify to participate in the study. For approval, a surgeon must perform at least 12 carotid endarterectomies per year. Based on a review of the surgeon's last 50 consecutive endarterectomies, the combined neurological morbidity and mortality rate must be no greater than 5% for all indications and no greater than 3% for endarterectomies performed on asymptomatic patients. RESULTS: One hundred sixty-four surgeons from 48 centers applied for approval: 117 were approved, 17 were rejected, and 30 were not reviewed. The 117 approved surgeons submitted a total of 5,641 endarterectomies with a combined mortality and neurological morbidity rate of 2.3% for the variety of indications for operation. CONCLUSIONS: This overall experience with carotid endarterectomy is one of the largest series reported to date. The data from approved surgeons are well within the range of acceptable neurological morbidity and mortality rates recommended by the Stroke Council of the American Heart Association, which attests to the overall quality of the surgeons participating in the study.

Carotid Artery Diseases↗
PubMed1991

Cerebral infarction verified by cranial computed tomography and prognosis for survival following transient ischemic attack.

Of 564 consecutive patients with transient ischemic attack, 350 (62%) had cranial computed tomography performed. Except for date of admission and smoking history, there were few differences between the patients evaluated with computed tomography and the 214 who were not. Cerebral infarcts were found in 59 (17%) of the 350 tomographic evaluations. Previous clinically diagnosed stroke, older age, and male sex were all significantly associated with the occurrence of tomographically verified infarcts (p less than 0.05). After controlling for stroke history and other important covariates, patients with tomographically verified infarcts had significantly shorter survival times than did patients without evidence of infarction on computed tomography (p = 0.035). Thus, cranial computed tomography findings appear to have important prognostic value for estimating survival following transient ischemic attack.

Cerebral Angiography↗
PubMed1990

Characteristics of stroke victims associated with early cardiovascular mortality in their children.

We assessed the relationship between characteristics of stroke victims and the risk of early death from coronary or cerebrovascular disease (CCVD) among their children. For each of 55 stroke patients selected from a registry which enrolled patients between 1969 and 1973, an index of their progeny's survival was calculated using the age in 1987 of 197 surviving children, and the age at and cause of death for 55 deceased children. Increased risk of CCVD death within families was significantly related to parental age at the time of first stroke, and with the parental history of diabetes mellitus. No significant relationship was found between the children's risk of CCVD death and the stroke patient/parent's sex, race, history of hypertension or cardiac disease, stroke diagnosis (infarction vs hemorrhage), or severity upon admission. These results suggest that family histories of cerebrovascular disease may impart differential risks, depending upon a family history of diabetes, and perhaps, the ages at which ancestral strokes first occurred.

Adolescent↗
PubMed1990

Evaluation of the associations between carotid artery atherosclerosis and coronary artery stenosis. A case-control study.

To evaluate the consistency, strength, and independence of the relation of carotid atherosclerosis to coronary atherosclerosis, we quantified coronary artery disease risk factors and extent of carotid atherosclerosis (B-mode score) in 343 coronary artery disease patients and 167 disease-free control patients. In univariable analyses, there was a strong association between coronary status and extent of carotid artery disease in men and women older than and younger than 50 years (p less than 0.001 for men and women greater than 50 years, p less than 0.001 for women less than or equal to 50 years, p = 0.045 for men less than or equal to 50). The relation remained strong after control for age in men and women older than 50 years and in women younger than 50 (p less than 0.001 for men and women greater than 50 years, p = 0.003 for women less than or equal to 50) but did not persist after control for age in men younger than 50. Logistic models that included coronary disease risk factors, with or without B-mode score, as independent variables and presence or absence of coronary disease as the outcome variable indicated that the extent of carotid atherosclerosis was a strong, statistically significant independent variable in models for men and women older than 50 years of age. Next, we examined the usefulness of B-mode score as an aid in screening for coronary artery disease in men and women older than 50 years. Classification rules, both including and excluding B-mode score, were developed based on logistic regression and, for comparison, recursive partitioning (decision trees). The performance of these rules and the bias of their performance statistics were estimated. The improved classification of the study sample when B-mode score was incorporated in the rule was statistically significant only for men (p = 0.015). However, the addition of B-mode score was found to 1) increase the median discrimination score for both sex groups based on the logistic model, and 2) yield better sensitivities and specificities for rules based on recursive partitioning. Thus B-mode score is strongly, consistently, and independently associated with coronary artery disease in patients older than 50 and is at least as useful as well-known risk factors for identifying patients with coronary artery disease.

Aging↗
PubMed1990

Community hospital-based stroke programs in North Carolina, Oregon, and New York. IV. Stroke diagnosis and its relation to demographics, risk factors, and clinical status after stroke.

The use of diagnostic tests, the accuracy of stroke type diagnosis, and their relationship to outcome are important from the standpoint of patient management and health care costs. To address this issue, we examined the differences between stroke types in terms of demographics, risk factors, diagnostic tests, and clinical outcome in the 4,129 patients who comprise the Community Hospital-Based Stroke Program. Previous transient ischemic attacks were equally frequent among patients with embolic and those with thrombotic stroke. For all stroke types, previous stroke was as frequent as previous transient ischemic attacks. Hypertension and cardiac disease were the most common risk factors, but 10% of all stroke patients had no recognized risk factors. Intracerebral hemorrhage was most often associated with death (45%). There was a strong direct relation between in-hospital mortality and a decreased level of consciousness at admission. Overall, 30% of patients did not receive a specific stroke type diagnosis; these patients were elderly, usually nonwhite, and often had an altered level of consciousness at admission but had a risk factor profile similar to that of patients who received a specific stroke type diagnosis. In summary, our findings suggest the continued need for physician education about and refinement of stroke type diagnosis.

Aged↗
PubMed1989

Cigarette smoking cessation and extracranial carotid atherosclerosis.

Using B-mode ultrasonography, cigarette smoking was found to be a strong, independent risk factor for extracranial carotid atherosclerosis in 1692 black and white men and women admitted for diagnostic evaluation of the carotid arteries. We found that the difference in mean plaque thickness was smaller between past smokers and nonsmokers than between current smokers and nonsmokers, suggesting that the rate of progression of carotid atherosclerosis may be slower in people who quit smoking compared with people who continue to smoke.

Adult↗
PubMed1989

The effect of radiation on carotid arteries. A review article.

The effects of irradiation on blood vessels supplying the brain are reviewed. Short-term and long-term effects on large arteries result in an atheroscleroticlike disorder. The response may have a latency up to 20 years before the onset of symptoms and signs. This delay is probably related to the diameter of the irradiated artery; the interval is longer for larger arteries. However, it is possible that the apparent injury to the large arteries is in fact due to occlusion of the vasa vasorum because the microvasculature is especially vulnerable to radiation damage.

Animals↗
PubMed1989

Cerebral infarction in patients with transient ischemic attacks.

Cranial computed tomography of 284 patients with transient ischemic attacks (TIAs) and without previous stroke was evaluated. The sample population included patients with carotid and/or vertebrobasilar TIAs. Computed tomography revealed cerebral infarction in 34 patients, including 5 with multiple infarctions. The lesion location was consistent with TIA symptoms in 16 patients. In another 16 patients, however, the lesion location did not correspond to the TIA symptoms; these lesions were attributed to previous silent infarctions. Two patients with multiple infarctions had both symptomatic and asymptomatic lesions. Age and carotid stenosis were each significantly related to an increased chance of detecting cerebral infarction (either symptomatic or asymptomatic). No significant relationship between race, gender, hypertension, diabetes, cardiac disease, or smoking and the incidence of infarction was found by either univariate or multivariate analyses.

Aged↗
PubMed1989

Correlation of carotid bruits and carotid atherosclerosis detected by B-mode real-time ultrasonography.

The extent of carotid atherosclerosis evaluated by B-mode real-time ultrasound and the presence of bruits established by carotid phonoangiography were determined in 1,107 patients. Unilateral bruit was associated with increased atherosclerosis compared with no bruit (p less than or equal to 0.0001). However, there was no association between laterality of the bruit and the degree of atherosclerosis (p = 0.66). There was marginal evidence that patients with bilateral bruits had more severe atherosclerosis than patients with unilateral bruit (p = 0.046). The relation between bruit and atherosclerosis categorized by B-mode ultrasound was not sufficient to reliably predict the presence or absence of disease in an individual patient, though the presence of a bruit should be viewed as a risk factor for, or an indicator of, increased risk of systemic atherosclerosis.

Auscultation↗
PubMed1989

Pentoxifylline increases cerebral blood flow in patients with cerebrovascular disease.

We determined the immediate effects of pentoxifylline on cerebral blood flow in 10 patients with cerebrovascular disease; four received 400 mg and six received 800 mg pentoxifylline orally. Regional cerebral blood flow was measured before (baseline) and 2, 4, and 6 hours after pentoxifylline administration using the xenon-133 clearance technique with 16 detectors (eight per hemisphere). Global cerebral blood flow as a percentage of the baseline value increased significantly after 800 mg but not 400 mg pentoxifylline (p = 0.017 and p = 0.29, respectively). Regional cerebral blood flow as a percentage of the baseline value at the detector with the lowest baseline value increased significantly 2 hours after both 400 mg and 800 mg pentoxifylline (p = 0.038 and p = 0.010, respectively). Cerebrovascular reactivity to carbon dioxide was preserved despite the increases in cerebral blood flow. Pentoxifylline increases cerebral blood flow and is not associated with "intracerebral steal" in patients with cerebrovascular disease.

Aged↗
PubMed1989

Extracranial carotid atherosclerosis in black and white patients with transient ischemic attacks.

To evaluate the association between extracranial carotid atherosclerosis, race, and transient ischemic attack, we carried out a retrospective hospital chart review and quantified the extent of noninvasively determined extracranial carotid atherosclerosis in 25 black patients greater than 45 years old with transient ischemic attacks. Two sex- and age-matched white patients with transient ischemic attacks were similarly studied for each black patient. Extent of extracranial carotid atherosclerosis (expressed as B-mode score) was similar for blacks and whites. B-mode score was only slightly less in patients with posterior- than in those with anterior-circulation transient ischemic attacks. Fifty-six patients (35 white, 21 black) had unilateral anterior-circulation transient ischemic attacks. Of the 32 patients with more extensive extracranial carotid atherosclerosis ipsilateral to the affected hemisphere, 23 (66% of 35) were white; only nine (43% of 21) were black. In the 35 white patients, the extent of disease in the ipsilateral carotid artery was significantly greater (p less than 0.03) than that in the contralateral carotid artery. When B-mode scores in the left and right carotid arteries were combined for the subgroup of patients with unilateral anterior-circulation transient ischemic attacks, blacks had slightly more atherosclerosis in the extracranial arteries than whites.

Arteriosclerosis↗
PubMed1989

Changes in survival after transient ischemic attacks: observations comparing the 1970s and 1980s.

We compared survival following transient ischemic attack (TIA) in 2 prospective cohorts of TIA patients admitted to Wake Forest University Medical Center. The 1st consisted of 177 patients admitted between 1961 and 1973, and the 2nd of 185 patients admitted between 1980 and 1983. Patients in the 2nd cohort had significantly greater longevity than patients in the 1st cohort, both univariately and after adjustment for cerebrovascular risk factors. The adjusted 1-year survival estimate increased from 91% in the 1st cohort to 98% in the 2nd, and the adjusted 3-year survival estimate increased from 83% in the 1st to 94% in the 2nd. The underlying causes for this dramatic improvement in survival may include early identification and aggressive management of TIAs or coexisting diseases, improved management of subsequent completed strokes or myocardial infarctions, or unadjusted differences in these cohorts. The data imply that reports of TIA survival from different periods may not be comparable.

Cohort Studies↗