Stroke incidence and survival among middle-aged adults: 9-year follow-up of the Atherosclerosis Risk in Communities (ARIC) cohort

BACKGROUND AND PURPOSE

Although stroke mortality rates in the United States are well documented, assessment of incidence rates and case fatality are less well studied.

METHODS

A cohort of 15 792 men and women aged 45 to 64 years from a population sample of households in 4 US communities was followed from 1987 to 1995, an average of 7. 2 years. Incident strokes were identified through annual phone contacts and hospital record searching and were then validated.

RESULTS

Of the 267 incident definite or probable strokes, 83% (n=221) were categorized as ischemic strokes, 10% (n=27) were intracerebral hemorrhages, and 7% (n=19) were subarachnoid hemorrhages. The age-adjusted incidence rate (per 1000 person-years) of total strokes was highest among black men (4.44), followed by black women (3.10), white men (1.78), and white women (1.24). The black versus white age-adjusted rate ratio (RR) for ischemic stroke was 2.41 (95% CI, 1.85 to 3.15), which was attenuated to 1.38 (95% CI, 1.01 to 1.89) after adjustment for baseline hypertension, diabetes, education level, smoking status, and prevalent coronary heart disease. There was a tendency for the adjusted case fatality rates to be higher among blacks and men, although none of the case fatality comparisons across sex or race was statistically significant.

CONCLUSIONS

After accounting for established baseline risk factors, blacks still had a 38% greater risk of incident ischemic stroke compared with whites. Identification of new individual and community-level risk factors accounting for the elevated incidence of stroke requires further investigation and incorporation into intervention planning.

Risk factors for new atherothrombotic brain infarction in older African-American men and women

Independent risk factors for new atherothrombotic brain infarction (ABI) in older African-American men were hypertension (risk ratio 4.381), diabetes mellitus (risk ratio 2.872), and previous ABI (risk ratio 1.904). Independent risk factors for new coronary events in older African-American women were cigarette smoking (risk ratio 2.754), hypertension (risk ratio 5.914), diabetes mellitus (risk ratio 3.464), serum total cholesterol (risk ratio 1.008), serum high-density lipoprotein cholesterol (inverse association) (risk ratio 0.958), age (risk ratio 1.026), and previous ABI (risk ratio 2.601).

Utilities for major stroke: results from a survey of preferences among persons at increased risk for stroke

BACKGROUND

Patient beliefs, values, and preferences are crucial to decisions involving health care. In a large sample of persons at increased risk for stroke, we examined attitudes toward hypothetical major stroke.

METHODS AND RESULTS

Respondents were obtained from the Academic Medical Center Consortium (n = 621), the Cardiovascular Health Study (n = 321 ), and United Health Care (n = 319). Preferences were primarily assessed by using the time trade off (TTO). Although major stroke is generally considered an undesirable event (mean TTO = 0.30), responses were varied: although 45% of respondents considered major stroke to be a worse outcome than death, 15% were willing to trade off little or no survival to avoid a major stroke.

CONCLUSIONS

Providers should speak directly with patients about beliefs, values, and preferences. Stroke-related interventions, even those with a high price or less than dramatic clinical benefits, are likely to be cost-effective if they prevent an outcome (major stroke) that is so undesirable.

Differences in stroke between white, Hispanic, and Native American patients: the Barrow Neurological Institute stroke database

BACKGROUND AND PURPOSE

Identification of specific features of stroke in minority populations should lead to more effectively focused treatment and prevention.

METHODS

We examined 1290 white (WHI), 242 Hispanic (HIS), 83 Native American (NA), and 101 other stroke and transient ischemic attack (TIA) patients hospitalized at the Barrow Neurological Institute from 1990 through 1996.

RESULTS

Chi-square analysis detected significant (P<.05) differences as follows: (1) Stroke types--lacunes more prevalent in NA than WHI and HIS (30% versus 16% and 15%); cardioembolic more prevalent in WHI than HIS (16% versus 9%, NA 14%); hemorrhages more prevalent in HIS than WHI and NA (48% versus 37% and 27%); (2) Risk factors--hypertension more prevalent in HIS than WHI (72% versus 66%; NA 71%); diabetes more prevalent in NA than HIS and WHI (62% versus 36% and 17%); cigarette smoking more prevalent in WHI than HIS and NA (61% versus 46% and 41%); cardiac disease more prevalent in WHI than HIS (34% versus 24%; NA 27%); heavier alcohol intake in NA than HIS than WHI (43% versus 24% versus 17%). There were no significant outcome differences between races for any stroke type. ANOVA detected significantly lower mean age at stroke onset in NA than HIS than WHI (56 versus 61 versus 69 years).

CONCLUSIONS

There are significant differences in prevalence of risk factors and stroke types between WHI, HIS, and NA in our hospital-based population. Although the three races appear to respond to risk factors similarly, Hispanics may be especially susceptible to hemorrhage. Further evaluation of these observations in community-based studies will be important.

Hyperhomocysteinaemia in black patients with cerebral thrombosis

Hyperhomocysteinemia is regarded as a risk factor for stroke but its pathogenetic role has not yet been established in Black patients. We studied 24 Black patients admitted with cerebral thrombosis, and compared them with age- and sex-matched apparently healthy controls from the same community. Total homocysteine (tHcy) (free homocysteine, protein-bound homocysteine, the disulfide homocystine and the mixed disulfide homocysteine-cysteine) concentration was 10.91 (4.95-23.05) mumol/l in the stroke patients and 8.73 (3.95-15.10) mumol/l in controls (p = 0.031). This difference could not be explained by differences in vitamin B12, vitamin B6 or folate status. A subgroup of nine stroke patients with hypercreatininaemia (> 90 mumol/l, 75% of control concentrations) had significantly higher plasma tHcy concentrations [median (range) 9.10 (5.40-15.10) mumol/l] compared with controls [8.65 (3.96-13.89) mumol/l] (p = 0.002). Plasma tHcy concentrations of stroke patients with normal serum creatinine concentrations were not significantly different to those of controls. Hyperhomocysteinemia in Black patients with stroke may be partially caused by renal insufficiency. Therefore, while hyperhomocysteinemia may increase the risk of stroke, it is unlikely to be a primary initiating factor.