Transient ischemic attacks and risk of stroke in an elderly poor population

Investigation of the Transient Ischemia Workload and its Incidence: Implications for Occupational Therapy Research

With limited effectiveness of medical and surgical intervention following stroke, the focus has shifted to preventing stroke and the most important warning sign of an impending stroke, the Transient Ischemic Attack (TIA) or the “mini stroke.” We found that the incidence of hospital admissions for the TIA patients in a population of slightly more than 1 million (660,598 people 25 years and older) was 1.18 per 1,000 men, or a total of 386 men, and 0.73 per 1,000 women, or a total of 258 women. The overall admission rate was 0.95 per 1,000 people 25 and older. For those hospitalized, the mean age was 67.9 years for men, and 71.3 years for women. Our epidemiological study of hospital admissions and the cases reported and managed by the general medical practitioners in the community showed the crude incidence rate of 2.89 per 1,000 people 25 years and older, while the adjustment for the world standardized population rate yielded a value of 1.26 per 1,000, or 44% of the crude rate that was actually observed. There appeared to be a marked disparity between the reported female and male cases of TIA. The research discussion focuses on two equally important thrusts: 1) development of strategies to reduce identified risk factors for stroke, and 2) establishment of a premorbid patient profile by occupational therapists that will have widespread implications for identifying changes for the potential prevention and treatment of stroke.

Stroke: epidemiology, clinical picture, and risk factors--Part I of III

The aim of this review is to present the current knowledge regarding stroke. It will appear in three parts (in part II the pathogenesis, investigations, and prognosis will be presented, while part III will consist of the management and rehabilitation). In the current part (I) the definitions of the clinical picture are presented. These include: amaurosis fugax, vertebrobasilar transient ischemic attack, and stroke (with good recovery, in evolution and complete). The role of the following risk factors is discussed in detail: age, gender, ethnicity, heredity, hypertension, cigarette smoking, hyperlipidemia, diabetes mellitus, obesity, fibrinogen and clotting factors, oral contraceptives, erythrocytosis and hematocrit level, prior cerebrovascular and other diseases, physical inactivity, diet and alcohol consumption, illicit drug use, and genetic predisposition. In particular, regarding the carotid arteries, the following characteristics are analyzed: atheroma, carotid plaque echomorphology, carotid stenosis, presence of ulcer, local variations in surface deformability, pathological characteristics, and dissection. Finally the significance of the cerebral collateral circulation and the conditions predisposing to cardioembolism and to cerebral hemorrhage are presented.

The effect of treating people with reversible ischaemic attacks of the brain and eye on the incidence of stroke in Australia

BACKGROUND

Reversible ischaemic attacks of the brain or eye (RIA) are a risk factor for stroke. Strategies of stroke prevention include vascular risk factor control, antithrombotic therapy, and carotid surgery.

AIMS

To determine the effectiveness, risks and costs of each stroke prevention strategy for patients with RIA and the Australian community, and the effect of treating people with RIA on the incidence of stroke in Australia.

METHODS

Review of data from prospective community-based studies to determine the prevalence of RIA, the incidence of stroke, and the proportion of stroke patients who report a RIA before their stroke; and data from randomised trials to determine the effectiveness, risks and costs of treatments for RIA.

RESULTS

About 111,000 Australians have had a prior RIA. Each year, about 37,000 Australians suffer a stroke, of whom up to 8000 (22%) have had a prior ('warning') RIA. Targeting effective stroke prevention strategies to RIA patients with relevant treatable conditions may reduce the individual's stroke risk by two-thirds (individual strategies) and possibly further (combination strategies). However, because the attributable risk of RIA for stroke is only about 22% (and may be less, given the role of other causal risk factors for stroke), strategies of stroke prevention in RIA patients can only reduce stroke incidence by up to 15% (from 22% to 7%).

CONCLUSIONS

The potential benefits of the 'high risk' approach to stroke prevention appear to be less than the 'population' approach, but both approaches are necessary and complementary. Indeed, the cost of implementing the 'high risk' approach may be less than the cost of the strokes prevented ($255 million; i.e. 15% of $1.7 billion).

Pattern and frequency of recurrent transient ischemic attacks

Objectives. Natural history studies and stroke prevention trials in patients with transient ischemic attacks (TIAs) have focused primarily on stroke or death outcomes and not recurrent TIA, yet treatment decisions are often based on recurrences. This study was undertaken to evaluate the frequency and pattern of recurrent TIAs in patients presenting with their first TIA. Methods. We monitored TIA recurrence for an average of 16 months in 47 consecutive patients hospitalized in a tertiary care center within 3 weeks of their first TIA. Treatment in 22 patients was aspirin or ticlopidine alone, and 12 underwent endarterectomy. Remaining patients received warfarin, dipyridamole, or pentoxifylline alone or with aspirin, including two who underwent endarterectomy. Treatment was changed in only four patients during the follow-up period. Results. Thirty-four patients (72%) had more than one TIA; 23 of these (68%) had two to five recurrences and 11 (32%) had more than five TIAs. Nineteen of the 34 patients with multiple TIAs had recurrences within 1 month of the initial TIA. Only four patients (12%) had recurrent TIAs throughout the follow-up period. Stroke occurred in five patients (11%); one patient had a single prior TIA, and the rest had multiple TIAs. No risk factors or treatments predicted which patients had single or multiple TIAs. Conclusions. Most patients have few recurrent TIAs, and recurrences usually occur within the first month of the initial TIA. The patterns of TIA recurrence identified should aid in treating patient and in devising appropriate outcome measures in treatment trials in which TIA is an endpoint.

The prognosis of hospital-referred transient ischaemic attacks

A cohort of 469 hospital-referred patients with transient ischaemic attacks (TIA) of the brain (66%) or eye (34%) due to presumed atheromatous thromboembolism, lipohyalinosis or cardiogenic embolism, without prior stroke, was assembled between 1976-86. Follow up was prospective and complete until the patients death or the end of 1986. During a mean period of follow up of 4.1 years there were 82 deaths (58 vascular, 24 non-vascular), 63 first-ever strokes and 58 patients with coronary events. A coronary event accounted for 51% of deaths whilst stroke was the cause in 12%. The average risk of death over the first five years after TIA was 4.5% per year. The risk of stroke was 6.6% in the first year and 3.4% per year on average over the first five years. Stroke occurred in the same vascular territory as the initial TIA in about two-thirds of cases, and was of lacunar type in one fifth of these strokes. The average risk of a coronary event over the first five years after TIA was 3.1% per year, similar to that of stroke. However, the risk of a coronary event, and also death, was fairly constant each year after a TIA, in contrast to the risk of stroke which was highest in the first year. The average risk of stroke, myocardial infarction or vascular death over the first five years after TIA was 6.5% per year and the average risk of stroke, myocardial infarction or death from any cause was 7.5% per year. The prognosis of this cohort of hospital-referred TIA patients was better than that of TIA patients in the same community who presented to the Oxfordshire Community Stroke Project (OCSP), and reflected the impact of referral bias. The hospital-referred patients were younger, assessed at a later date after their last TIA, and comprised a greater proportion of patients who had had a TIA of the eye (amaurosis fugax), which had a better prognosis than TIA of the brain. Knowledge of the prognosis of different populations of TIA patients not only enhances understanding and interpretation of previous studies but is also required for optimal patient management and the planning of treatment trials.

Heparin therapy for recent transient focal cerebral ischemia

The Mayo Clinic medical records and records linkage system were used to identify stroke-free residents of Rochester, Minnesota, who were examined within 30 days after the first transient cerebral ischemic attack (TIA) during the period 1955 through 1979. The patients were divided into two groups: those given heparin within 30 days after the first attack and those not given heparin. Death, stroke, and either stroke or TIA were separate endpoints in Kaplan-Meier analyses of data from the day of initial examination through the 30th day thereafter. The probabilities of survival, survival free from stroke, and survival free from TIA for the heparin-treated group were not significantly different from those probabilities for the comparison group. The rate of hemorrhagic complications was 3.2 per 100 person-days of heparin therapy. Retroperitoneal hemorrhage, the most serious complication, was the cause of one death and one case of femoral neuropathy.

Dipyridamole: a critical evaluation

Dipyridamol is a vasodilator that is used primarily in clinical practice as an antiplatelet agent. It increases coronary blood flow and was originally introduced as an antianginal agent. An ability to prolong a shortened platelet survival has been used to justify its value in preventing thromboembolic complications. Conditions characterized by a reduction in platelet survival and where dipyridamole has been used include heart valve replacement, arterial grafting, cerebrovascular disorders, and disorders of peripheral circulation. The in vivo effect of dipyridamole on platelet aggregation has not been well defined and may depend on additional factors. Prostaglandins appear to have important roles in platelet homeostasis; their relationships to the action of dipyridamole are discussed. Dipyridamole usually is combined with aspirin for synergistic anti-aggregatory purposes. However, the nature of the interaction has not been elucidated and benefit from the addition of dipyridamole has not been demonstrated in clinical studies. A review of clinical studies using dipyridamole indicates that it currently has limited value.

Clinical significance of transient visual phenomena in the elderly

To evaluate the significance of transient visual phenomena in the elderly patient, a retrospective study of 43 patients over 40 years of age (mean, 58) presenting between 1971 and 1982 was conducted. Historical, clinical and diagnostic features were collated and analyzed by computer. The study revealed that 31 patients were diagnosed as migraine and 12 as vertebrobasilar insufficiency based on features identified in this review. Follow-up was obtained in 90% of the patients with a mean follow-up of 2.4 years. In general, prognosis proved to be excellent, with two deaths of cardiac origin and an 81% incidence of remission or symptomatic improvement of the visual events. No retinal or cerebral strokes were observed and TIAs occurred in only 9% of the population. This study suggests that transient visual phenomena in the elderly are benign.

Unexpected trends in the analysis of a questionnaire and interview procedure to detect transient cerebral ischemic attack in a female population

By means of a case-control study, social and biomedical factors were considered in relation to transient cerebral ischemic attack occurrence as determined by questionnaire and interview among a population of females ( greater than 50 years of age) residing in the city of utrecht and surroundings. Contrary to earlier expectations, a greater TIA risk was found associated with: lower systolic and diastolic blood pressure, a low-salt diet for high blood pressure, lower body weight, smaller body surface, and use of medicines for cardiac insufficiency/arrhythmias and chronic anxiety. The importance of hemodynamic processes (i.e. hypotensive episodes of cerebral circulation) for TIA within the general population is emphasized.

Use of a self-administered questionnaire for detection of transient cerebral ischemic attacks: I. Survey of elderly persons living in retirement facilities

A self-administered questionnaire designed to identify people with transient cerebral ischemia (TIA) in large population groups was distributed to approximately 10,000 elderly persons living in public and private retirement facilities in the United States. The population resided in eight cities, and 74% completed the survey. Transient focal neurological symptoms compatible with a diagnosis of TIA within the previous year were reported by 6.4% of the respondents. Uncertain manifestations of TIA, i.e., dizziness, light-headedness, or loss of balance, were noted by an additional 15.4%; the remaining 78.2% had no manifestations of this disorder. A clinical history for TIA was taken by a neurologist in a sample of 1,712 respondents to determine the validity of the questionnaire responses. Thirty (7.1%) of 423 persons presumed by the questionnaire to have TIA met the standard clinical criteria for the diagnosis. An additional 8 cases of TIA were found by the neurologist among the 1,289 interviewed persons presumed by the questionnaire to have uncertain TIA or no evidence of the disorder. The twelve-month period prevalence of TIA was estimated to be 8.2 per 1,000 in the total respondent population and 5.8 per 1,000 among those without a history of prior completed stroke. Despite the high proportion of false-positive neurological symptoms of TIA elicited by the questionnaire, this survey instrument nevertheless screened out for further study the 6% of the population in whom 55% of the TIAs occurred.

A prospective epidemiological survey of cerebrovascular disease in a Swedish community

A prospective epidemiological study of cerebrovascular diseases and transient ischemic attacks (TIA) is presented. During a three-year period the annual incidence of strokes was 2.90 and of TIA 0.45 per thousand population. This difference in incidence and the disparities in age characteristics favour the hypothesis that TIA precedes only a minority of the strokes. The short-term mortality is high among the stroke patients.