American Heart Association Prevention Conference. IV. Prevention and Rehabilitation of Stroke. Risk factors.
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Publications and source records attributed to T A Manolio.
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INTRODUCTION: A decrease in the estimated relative risk of cerebrovascular and cardiovascular diseases associated with known disease risk factors has been observed among elderly cohorts, perhaps suggesting that continued risk factor management in the elderly may not be as efficacious as with younger age groups. In this paper, the differential magnitude of the association of risk factors with atherosclerosis across the age spectrum from 45 years to older than 75 years is presented. METHODS: Subclinical atherosclerosis as measured by carotid ultrasonography and risk factor prevalence were assessed using similar methods among participants aged 45 to 64 years in the Atherosclerosis Risk in Communities (ARIC) study and among participants 65 years and older in the Cardiovascular Health Study (CHS). Pooling these two cohorts provided data on the relationship of risk factors and atherosclerosis on nearly 19,000 participants over a broad age range. Regression analyses were used to assess the consistency of the magnitude of the association of risk factors with atherosclerosis across the age spectrum separately for black and white participants in cross-sectional analyses. RESULTS: As expected, each of the risk factors was globally (across all ages) associated with increased atherosclerosis. However, the magnitude of the association did not differ across the age spectrum for hypertension, low density lipoprotein cholesterol (LDL-c), fibrinogen, or body mass index (BMI). For whites, there was a significantly greater impact of smoking and HDL-C among older age strata but a smaller impact of diabetes. For black women, the impact of HDL-C decreased among the older age strata. CONCLUSIONS: These data suggest that most risk factors continue to be associated with increased atherosclerosis at older ages, possibly suggesting a continued value in investigation of strategies to reduce atherosclerosis by controlling risk factors at older ages.
A wealth of information on pulmonary function is currently available in NHLBI-sponsored, population-based studies. These data can be used to address critically important questions in pulmonary and cardiovascular disease research, but their potential cannot be realized without the active collaboration of pulmonary- and cardiovascular-disease researchers. Investigators interested in analyzing these data in collaboration with the parent study investigators are invited to contact these investigators directly (see APPENDIX). Results of analyses recommended in the workshop should be used to identify hypotheses for future efforts in collecting data on the epidemiology of pulmonary diseases and their relationship to cardiovascular disease.
Associations of carotid artery diameter and intimal-medial thickness by ultrasound with echocardiographic left ventricular (LV) structure were examined in 3,409 participants in the Cardiovascular Health Study, a population-based study of risk factors for coronary heart disease and stroke in men and women aged > or = 65 years. At baseline, sector-guided M-mode echocardiography and B-mode ultrasound were used to evaluate the left ventricle and carotid arteries, respectively. Common carotid artery diameter and intimal-medial thickness were significantly related to LV mass in correlational analysis (r=0.40 and 0.20, respectively, p<0.01), and each was independently associated with LV mass after adjustment for age, gender, weight, systolic and diastolic blood pressure, antihypertensive medication use, prior coronary heart disease, electrocardiographic abnormalities, high-density lipoprotein, and factor VII. We speculate that changes in the arterial wall affect impedance to LV ejection leading to increases in LV mass. Further follow-up of this cohort is in progress and will help to determine whether such carotid artery measures could, by exacerbating LV hypertrophy, constitute another important risk factor for adverse cardiovascular outcomes.
The cardioprotective effects of combined estrogen/progestin replacement therapy have been questioned. Therefore, we have compared carotid arterial wall thickening and the prevalence of carotid stenosis in elderly women (> or = 65 years old) currently using replacement estrogen/progestins (E + P) with arterial pathology and its prevalence in women using unopposed estrogens (E). This cross-sectional study used baseline data from all 2962 women participating in the Cardiovascular Health Study, a population-based study of coronary heart disease and stroke in elderly adults. Users of hormone replacement therapy (HRT) were categorized as never (n = 1726), past (n = 787), current E (n = 280), or current E + P (n = 73). Maximal intimal-medial thicknesses of the internal and common carotid arteries and stenosis of the internal carotid arteries were measured by ultrasonography. Current E + P users resembled current E users in most respects, although some lifestyle factors were more favorable among E + P users. Current E + P use and current E use (as compared with no use) were associated with smaller internal carotid wall thicknesses (-0.22 mm; P = 0.003; and -0.09 mm; P = 0.05, respectively) and smaller common carotid wall thicknesses (-0.05 mm; P = 0.03; and -0.02 mm; P = 0.1, respectively) and lower odds ratios (OR) for carotid stenosis (> or = 1% vs. 0%); OR = 0.61; 95% confidence interval [CI]: 0.36 to 1.01; and OR = 0.91, 95% CI: 0.67 to 1.24, respectively), after adjustment for current lifestyle and risk factors. When both groups of current HRT users were compared, there were no significant differences in carotid wall thicknesses or prevalence of carotid stenosis. For this sample of elderly women, both current E + P therapy and current E therapy were associated with decreased measures of carotid atherosclerosis. These measures did not differ significantly between the two groups of HRT users.
The objectives of this study were to describe the prevalence of snoring, observed apneas, and daytime sleepiness in older men and women, and to describe the relationships of these sleep disturbances to health status and cardiovascular diseases (CVD). A cross-sectional design was employed to study sleep problems, CVD, general health, psychosocial factors, and medication use. The subjects were participants in the Cardiovascular Health Study, which included 5,201 adults, aged 65 and older, who were recruited from a random sample of Medicare enrollees in four U.S. communities. Study measures employed were sleep questions, echocardiography, carotid ultrasound, resting electrocardiogram, cognitive function, cardiopulmonary symptoms and diseases, depression, independent activities of daily living (IADLs), and benzodiazepine use. Thirty-three percent of the men and 19% of the women reported loud snoring, which was less frequent in those over age 75. Snoring was positively associated with younger age, marital status, and alcohol use in men, and obesity, diabetes, and arthritis in women. Snoring was not associated, however, with cardiovascular risk factors or clinical CVD in men or women. Observed apneas were reported much less frequently (13% of men and 4% women) than snoring, and they were associated with alcohol use, chronic bronchitis, and marital status in men. Observed apneas were associated with depression and diabetes in women. In both men and women, daytime sleepiness was associated with poor health, advanced age, and IADL limitations. The conclusions of the study were that loud snoring, observed apneas, and daytime sleepiness are not associated cross-sectionally with hypertension or prevalent CVD in elderly persons.
Several multivariate statistical models have recently been introduced for estimation of left ventricular mass from standard 12-lead electrocardiographic measurements. The validity of these algorithms has not been adequately evaluated. The objective of this investigation was to compare the associations between echocardiographic and electrocardiographic left ventricular mass values with clinical and subclinical indexes of coronary heart disease. The evaluation was performed with participants of the Cardiovascular Health Study, a population-based sample of 5201 men and women aged 65 years and older. Echocardiographic M-mode measurements of left ventricular mass were performed from videotape recordings with the use of a strictly standardized protocol. Electrocardiographic algorithms of the Novacode program and new algorithms derived from the Cardiovascular Health Study population were used for left ventricular mass prediction. Echocardiographic and electrocardiographic determinations of left ventricular mass were technically successful in 3410 (65.6%) and 5013 (96.4%) participants, respectively. The Novacode model overestimated echocardiographic left ventricular mass. Compared with the Novacode model, the new Cardiovascular Health Study electrocardiographic model, which includes adjustment for body weight, eliminated left ventricular mass prediction bias and improved the correlation between echocardiographic and electrocardiographic left ventricular mass from .33 to .54 in women and from .46 to .51 in men. Echocardiographic and electrocardiographic models both demonstrated similar and about equally strong associations with overt and subclinical disease and with risk factors for left ventricular hypertrophy. These observations demonstrate the potential utility of electrocardiographic models for left ventricular mass estimation.
BACKGROUND AND PURPOSE: Our aim was to identify potential risk factors for and clinical manifestations of white matter findings on cranial MRI in elderly people. METHODS: Medicare eligibility lists were used to obtain a representative sample of 5888 community-dwelling people aged 65 years or older. Correlates of white matter findings were sought among 3301 participants who underwent MRI scanning and denied a history of stroke or transient ischemic attack. Participants underwent extensive standardized evaluations at baseline and on follow-up, including standard questionnaires, physical examination, multiple blood tests, electrocardiogram, pulmonary function tests, carotid sonography, and M-mode echocardiography. Neuroradiologists graded white matter findings from 0 (none) to 9 (maximal) without clinical information. RESULTS: Many potential risk factors were related to the white matter grade, but in the multivariate model the factors significantly (all P < .01) and independently associated with increased grade were greater age, clinically silent stroke on MRI, higher systolic blood pressure, lower forced expiratory volume in 1 second (FEV1), and income less than $50,000 per year. If excluded, FEV1 was replaced in the model by female sex, history of smoking, and history of physician-diagnosed hypertension at the baseline examination. Many clinical features were correlated with the white matter grade, especially those indicating impaired cognitive and lower extremity function. CONCLUSIONS: White matter findings were significantly associated with age, silent stroke, hypertension, FEV1, and income. The white matter findings may not be considered benign because they are associated with impaired cognitive and lower extremity function.
BACKGROUND AND PURPOSE: Risk factors for incident stroke have been examined in middle-aged persons, but less is known about stroke precursors in the elderly, who suffer the highest rates of stroke. Short-term risk factors for incident stroke were examined in a longitudinal, population-based study including extensive measures of subclinical disease. METHODS: Prospective study of 5201 women and men aged 65 years and older was undertaken in the multicenter Cardiovascular Health Study. RESULTS: During an average 3.31-year follow-up, 188 incident strokes occurred. Stroke incidence increased significantly with age and was similar in women and men. Factors associated with increased stroke risk in multivariate analysis included age, aspirin use, diabetes, impaired glucose tolerance, higher systolic blood pressure, increased time needed to walk 15 ft. frequent falls, elevated creatinine level, abnormal left ventricular (LV) wall motion and increased LV mass on echocardiography, ultrasound-defined carotid stenosis, and atrial fibrillation. Increased LV mass and carotid stenosis were associated with twofold and threefold increases in incidences of stroke, respectively (P < .001). Aspirin users had a 52% higher risk of stroke (relative risk, 1.52; 95% confidence interval, 1.1 to 2.0; P < .007) after adjustment for other factors. This association was present only among aspirin users without prior coronary disease, atrial fibrillation, claudication, or transient ischemic attack, who had an 84% higher risk (relative risk, 1.84; 95% confidence interval, 1.2 to 2.8). CONCLUSIONS: Short-term risk of stroke has a complex relationship with aspirin use and is strongly related to subclinical disease in this sample of older adults. These relationships should be considered in assessing stroke risk in the elderly, in whom recognized and subclinical cardiovascular disease is highly prevalent.
Pulmonary function was assessed by spirometry in 497 black and 2,980 white ambulatory elderly male and female participants of the Cardiovascular Health Study. The quality assurance program prompted technicians to exceed American Thoracic Society recommendations for spirometry. A "healthy" subgroup of 235 black and 1,227 white participants age 65 years and older was identified by excluding current and former smoker, and those with self-reported asthma or emphysema, congestive heart failure, and poor-quality results of spirometry tests, since those factors were associated with a lower FEV1. Reference equations and normal ranges for elderly blacks for measurements of FEV1, FVC, and the FEV1/FVC ratio were then determined from the healthy group. These elderly blacks had an FVC about 6% lower than elderly whites, even after correcting for standing height, sitting height (trunk length), and age. The popular use of spirometry reference values from studies of middle-aged white subjects by applying a 12% race correction factor for black patients appears to overestimate predicted values.
BACKGROUND: The objective of this study was to describe the distribution of echo left ventricular (LV) mass and its association with demographic and cardiovascular risk factors in a large race- and sex-balanced cohort of young adults. Recent epidemiological data have suggested that M-mode echocardiographically determined LV hypertrophy is an independent predictor of mortality and morbidity from coronary heart disease (CHD) in older adults. Echocardiographic LV mass has been associated in middle-aged and older adults with multiple factors including age, arterial blood pressure, body mass, and sex. However, there are few data describing the distribution of echo LV mass among black and white young adult men and women and relating LV mass to cardiovascular disease risk factors within race-sex subgroups. METHODS AND RESULTS: CARDIA (Coronary Artery Risk Development in Young Adults) is a multicenter study of young adults, including approximately equal proportions of black and white men and women aged 23 to 35 years at the time of echo examination (1990 through 1991). Two-dimensionally guided M-mode echocardiograms were attempted in 4243 participants with recordings deemed acceptable for calculation of LV mass, that is, of at least fair quality score, obtained in 3840 (90.5% of the 1990-1991 cohort). M-mode LV mass was calculated from the formula of Devereux and Reicheck, adapted for use with measurements made according to the American Society of Echocardiography Standards. LV mass was greater in men than in women and greater in blacks than in whites (P < .001) (mean +/- SD): black men, 176 +/- 42 g; white men, 169 +/- 40 g; black women, 135 +/- 38 g; and white women, 125 +/- 33 g. In all race-sex groups, LV mass was positively correlated (P < .0001) in bivariate analyses with body weight, subcapular skinfold thickness, height, and systolic blood pressure. In multivariate analyses, LV mass remained independently and positively related to body weight and systolic blood pressure and, when body weight was not considered, with subcapular skinfold thickness and height. In addition, the multivariate models allowed us to infer a direct relation between LV mass and both fatness and lean body mass. Weaker positive associations were noted of LV mass with pulse pressure in white participants and with physical activity in men. After adjustment for subscapular skinfold thickness, height, systolic and diastolic blood pressures, alcohol consumption, pulmonary function, smoking history, physical activity, total serum cholesterol, and family history of hypertension, LV mass remained higher in men than in women (P < .0001), in black men (167 +/- 43 g) than in white men (156 +/- 50 g, P < .0001), and in black women (142 +/- 49 g) than in white women (137 +/- 43 g, P < .002). CONCLUSIONS: In the healthy young adults of the CARDIA cohort, LV mass was highly correlated with body weight, subscapular skinfold thickness, height, and systolic blood pressure across race and sex subgroups. Furthermore, after adjustment for anthropometric, blood pressure, and other covariates, LV mass remained higher in men than in women and in blacks than in whites. Longitudinal studies are necessary to delineate the possible roles of these factors in the genesis of LV hypertrophy.
OBJECTIVE: To describe the changing patterns of antihypertensive medication use in the years immediately before and after the publication of the results of three major clinical trials of the treatment of hypertension in older adults. DESIGN: In this cohort study, adults 65 years or older were examined annually on four occasions between June 1989 and May 1992, and the use of antihypertensive medications was assessed by inventory at each visit. The four visits defined the boundaries of three study periods. For each study period, participants receiving antihypertensive therapy were either continuous users (n = 1667, 1643, and 1605, respectively) or starters (n = 157, 142, 120) of hypertensive therapy. The large clinical trials that convincingly proved the efficacy and safety of low-dose diuretic therapy in older adults were published during the latter parts of period 2 and the early parts of period 3. RESULTS: Among starters, the proportion initiating therapy on diuretics increased from 35.9% in period 2 to 47.5% in period 3, significantly so among women (P = .04). The proportions initiating other drugs displayed no significant trends. Among continuous users, the use of diuretics, beta-blockers, and vasodilators generally decreased over the 3-year period, while the use of calcium channel blockers and angiotensin-converting enzyme inhibitors increased significantly in each of the three periods (P < .05). The decline of 2.7% in the prevalence of diuretic use in period 1 abated during period 2 (1.8% decline), and it slowed significantly (P = .03) to almost a complete halt during period 3 (0.2% decline). The rate of increase in the use of calcium channel blockers slowed significantly (P = .01) between period 1 (+6.7%) and period 3 (+2.8%). CONCLUSIONS: Although other factors such as cost may have been important, the temporal trends in antihypertensive drug therapy coincided in time with and may have reflected in part the influence of the major clinical trials on the patterns of clinical practice.
BACKGROUND: Two new classes of antihypertensive agents were introduced in the 1980s, but their effectiveness in preventing heart disease and stroke has not been demonstrated. Lack of evidence of their efficacy might reasonably be expected to discourage their widespread use in management of hypertension. METHODS: Use of various classes of antihypertensive agents was estimated from published drug use information in an effort to estimate trends in antihypertensive drug use and evaluate the impact of these trends on costs of antihypertensive therapy in the United States. RESULTS: Proportionate use of the five major antihypertensive drug classes shifted markedly between 1982 and 1993. Diuretics accounted for 56% of all hypertensive drug mentions in 1982 but only 27% in 1993, a relative decline of 52%. Use of beta-blockers and central agents also declined during this period. Proportionate use of calcium antagonists showed the greatest gains, increasing from 0.3% to 27%, while the use of angiotensin-converting enzyme inhibitors increased from 0.8% to 24%. Given the higher costs of the newer agents, and assuming an estimated total cost of antihypertensive medications in 1992 of $7 billion, approximately $3.1 billion would have been saved had 1982 prescribing practices remained in effect in 1992. CONCLUSIONS: Use of calcium antagonists and angiotensin-converting enzyme inhibitors in hypertension has increased dramatically in the past 10 years. Without convincing evidence of the advantages of these agents, it is difficult to explain the continued decline in the use of less expensive agents, such as diuretics and beta-blockers, which are the only antihypertensive agents proved to reduce stroke and coronary disease in hypertensive patients.
BACKGROUND: Left ventricular (LV) hypertrophy, as measured by M-mode echocardiography, is an independent predictor of mortality and/or morbidity from coronary heart disease (CHD). LV global and segmental systolic dysfunction also have been associated with myocardial ischemia and cardiovascular morbidity and mortality. Echocardiographic data, especially two-dimensional, have not been available previously from multicenter-based studies of the elderly. This report describes the distribution and relation at baseline of echocardiographic LV mass and global and segmental LV wall motion to age, sex, and clinical disease category in the Cardiovascular Health Study (CHS), a cohort of 5201 men and women (4850 white) 65 years of age and older. METHODS AND RESULTS: M-mode LV mass adjusted for body weight increased modestly with age (P < .0001), increasing less than one gram per year increase in age for both men and women. After adjustment for weight, LV mass was significantly greater in men than in women and in participants with clinical CHD compared with participants with neither clinical heart disease nor hypertension (both P < .001). Across all CHS age subgroups, the difference in weight-adjusted LV mass by sex was greater in magnitude than the difference related to clinical CHD. M-mode measurements of LV mass could not be made in 34% of CHS participants, and this was highly related to age (29% in the 65 to 69 year versus 50% in the 85+ year age group, P < .001) and other risk factors. In participants with clinical CHD and with neither clinical heart disease nor hypertension, LV ejection fraction and segmental wall motion abnormalities were more prevalent in men than women (all P < .001). Of interest, 0.5% of men and 0.4% of women with neither clinical heart disease nor hypertension had LV segmental wall motion abnormalities, suggesting silent disease, compared with 26% of men and 10% of women in the clinical CHD group (P < .0001). Multivariate analyses revealed male sex and presence of clinical CHD (both P < .001) to be independent predictors of LV akinesis or dyskinesis. CONCLUSIONS: Significant baseline relations were detected between differences in sex, prevalent disease status, and echocardiographic measurements of LV mass and systolic function in the CHS cohort. Age was weakly associated with LV mass measurements and LV ejection fraction abnormalities. These relations should be considered in evaluating the preclinical and clinical effects of CHD risk factors in the elderly.
We examined correlates of ischemic episodes in 24-h ambulatory electrocardiograms (ECG) in a sample of 1511 men and women 65 years old and older. Ischemic episodes had a high prevalence period during early afternoon and also during morning hours after awakening, and the overall prevalence was 13% in men and 9% in women (P < 0.001 for gender difference). The prevalence was 9.6% in participants with no history of myocardial infarction and no major or minor resting ECG abnormalities. In multivariate analysis by logistic regression, being on digitalis medication was associated with over a three-fold risk of ischemic episodes, with an odds ratio (95% confidence limits) of 3.21 (1.80 to 5.74). Left ventricular hypertrophy by ECG and atrial fibrillation had almost a three-fold excess risk of ischemic episodes, with odds ratios 2.81 (1.37 to 5.74) and 2.63 (1.17 to 5.91), respectively. Isolated ST-T abnormalities had almost a two-fold excess of ischemic episodes, with an odds ratio of 1.89 (1.01 to 3.54). Being overweight was associated with a 33% reduced likelihood of ischemic episodes after adjustment for other factors, with an odds ratio of 0.67 (0.46 to 0.98). It is concluded that the prevalence of silent ischemic episodes is high in older men and women.
Cardiovascular and all-cause mortality are higher in black than white Americans, but racial differences in clinical and subclinical cardiovascular disease (CVD) have not been examined in older adults. Clinical and subclinical CVD and its risk factors were compared in 4926 white and 244 black men and women aged 65 years and older. Black participants had lower socioeconomic status and generally higher prevalences of CVD and its risk factors, except for adverse lipid profiles. Common carotid wall thickness was greater in black than white women, and ankle-arm blood pressure ratios were lower in black women and men (p < 0.01). After adjustment for CVD risk factors, common carotid walls were significantly thicker and ankle-arm ratios were lower in blacks than whites of both sexes, while internal carotid walls were significantly thinner in black women. Racial differences in clinical and subclinical CVD in older adults are similar to those reported in younger populations and do not appear to be explained by CVD risk factors.
The Cardiovascular Health Study provided the opportunity to determine the association of subclinical and clinical cardiovascular disease with pulmonary function in a population sample of elderly adults. Included were 2,955 women and 2,246 men over age 64 years who were recruited for this observational study from four communities and completed extensive examinations that included spirometry, echocardiograms, and blood pressure. Current smokers, past smokers with >20 pack-years of smoking, and persons with a history of asthma, chronic bronchitis, or emphysema were excluded from this analysis, leaving 2,784 (55%) of the cohort. Systolic hypertension or coronary artery disease was associated with 40- to 100-mL decrements in FEV1, and 50- to 150-mL decrements in FVC, while a history of congestive heart failure was associated with 200 to 300 mL lower FEV1 and FVC values (p < 0.0001), after correcting for age, height, and waist size. Higher left ventricular (LV) mass was also significantly associated with a decrease in FEV1 and FVC in multivariate models. This relationship was strongest with the end-diastolic LV posterior wall thickness component of LV mass. In summary, FEV1 and FVC are reduced in elderly persons with hypertension, ischemic heart disease, higher disease, higher LV mass, and congestive heart failure, though the magnitude of these associations is relatively small unless heart failure supervenes. Substantial decrements in percent predicted FEV1 and FVC should not be attributed to the presence of uncomplicated ischemic heart disease or hypertension alone.
Atrial fibrillation (AF) is a common arrhythmia in elderly persons and a common cause of embolic stroke. Most studies of the prevalence and correlates of AF have used selected, hospital-based populations. The Cardiovascular Health Study is a population-based, longitudinal study of risk factors for coronary artery disease and stroke in 5,201 men and women aged > or = 65 years. AF was diagnosed in 4.8% of women and in 6.2% of men at the baseline examination, and prevalence was strongly associated with advanced age in women. Prevalence of AF was 9.1% in men and women with clinical cardiovascular disease, 4.6% in patients with evidence of subclinical but no clinical cardiovascular disease, and only 1.6% in subjects with neither clinical nor subclinical cardiovascular disease. A history of congestive heart failure, valvular heart disease and stroke, echocardiographic evidence of enlarged left atrial dimension, abnormal mitral or aortic valve function, treated systemic hypertension, and advanced age were independently associated with the prevalence of AF. The low prevalence of AF in the absence of clinical and subclinical cardiovascular disease calls into question the existence and clinical usefulness of the concept of so-called "lone atrial fibrillation" in the elderly.