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Biomedical subjects

V J Howard

Publications and source records attributed to V J Howard.

27 records · Page 2Linked to original sources

Is the stroke belt disappearing? An analysis of racial, temporal, and age effects.

BACKGROUND AND PURPOSE: The stroke risk among white residents of the coastal plain of North Carolina, South Carolina, and Georgia (the "Stroke Belt") has been reported to be between 1.3 and 2.0 times the national average. In this study we examined (1) whether a similar excess risk exists for blacks in this region, (2) whether this regional excess stroke risk has decreased over time, and (3) whether the regional excess risk is consistent across ages from 45 to more than 85 years. METHODS: Using data from the Compressed Mortality File, we estimated the annual relative stroke mortality risk for black and white men and women in a region of 153 coastal plain counties and compared these rates to those for the remainder of the United States. RESULTS: The relative geographic excess risk of stroke death was similar for black residents and white residents of the Stroke Belt for both men and women. Despite the decline in stroke mortality, the relative increased risk of stroke death in the region has remained constant from 1968 to 1991; however, the pattern of excess risk across age differed significantly between race/sex groups. CONCLUSIONS: These data show that the Stroke Belt continues to exist for blacks and whites and for men and women. Although the specific causes of the Stroke Belt remain unknown, the public health impact is staggering, with a greater than 40% excess risk of stroke mortality and more than 1200 excess stroke deaths annually.

Age Factors↗

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↗

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↗

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↗

Nonbacterial thrombotic endocarditis. A neurologic perspective of clinicopathologic correlations of 99 patients.

Of 13,913 patients examined at autopsy between 1939 and 1980, the diagnosis of nonbacterial thrombotic endocarditis (NBTE) was made in 99 instances. There were 53 males and 46 females ranging in age from 4 to 89 years. Vegetations were found on the aortic valve in 39; the mitral in 37; the tricuspid in nine; and the mitral in 37; the tricuspid in nine; and the pulmonic in two. Two-valve involvement was present in 12 cases. Malignant neoplasms were found in 42 autopsies. Embolism to the brain was found in 33 cases and to other organs in 62. Coagulation abnormalities were documented in 22 cases, and a distinct picture of disseminated intravascular coagulation of thrombophlebitis elsewhere in the body should arouse suspicion of NBTE. The high incidence of multiple emboli and its association with malignant neoplasms and with a variety of cardiovascular, pulmonary, renal, and gastrointestinal disorders should provide clues for recognition of this serious disorder.

Adolescent↗

The sex difference in manifestations of carotid bifurcation disease.

One would think that risk factors for transient ischemic attack (TIA) and asymptomatic carotid bruit (ACB) would be similar. In our referral population and in several previously reported cohort populations, however, men outnumber women among patients with TIA. In contrast, women outnumber men among patients with ACB. We found in two independent populations that women with ACB are up to 5.7 times less likely than men to have carotid stenosis. Thus women are more prone than men to have ACB, but their bruits much less commonly reflect carotid stenosis. Women are probably predisposed to have carotid bruit even in the absence of carotid stenosis. In our referral population of ACB, this tendency among women for carotid bruit without stenosis does not seem to be related to lower hematocrit, higher prevalence of heart murmur, constitutionally smaller carotid arteries, or differences in pulse rate or body habitus.

Aged↗

Declining morbidity and mortality of carotid endarterectomy. The Wake Forest University Medical Center experience.

The 30-day mortality as well as morbidity for stroke and myocardial infarction were determined by review of the charts for every carotid endarterectomy (N = 389 operations on 356 patients) performed at Wake Forest University Medical Center from 1979 through 1983 to ascertain whether the 16% morbidity and 6% mortality documented in our previous report of 1978 had changed over time. For endarterectomies performed on asymptomatic patients (n = 155), major morbidity included 2 myocardial infarctions and 1 stroke (1.9%). There were 3 fatalities--2 myocardial infarctions and 1 stroke (1.9%). For the symptomatic group (n = 234), major morbidity was 2.1%, mortality 2.6%. The combined morbidity for asymptomatic and symptomatic carotid stenosis was 2%, mortality 2.3%. Perioperative stroke rate (morbidity plus mortality) was 2.6%, 9 ipsilateral to the carotid endarterectomy, suggesting distal embolism as its probable cause. We contend that quality control measures implemented to correct the unacceptable rates reported in 1978 have contributed to dramatic and sustained reductions in complication rates.

Academic Medical Centers↗