Correlates of QT prolongation in older adults (the Cardiovascular Health Study). Cardiovascular Health Study Collaborative Research Group.
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Biomedical subjects
Publications and source records attributed to T A Manolio.
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OBJECTIVES: This study describes the prevalence and correlates of cardiac arrhythmias in older persons. BACKGROUND: Cardiac arrhythmias are frequent in selected samples of elderly persons, but their prevalence and association with cardiovascular disease and its risk factors have not been examined in a large population-based sample. METHODS: In 1,372 participants in the Cardiovascular Health Study, a population-based study of cardiovascular disease risk factors, 24-h ambulatory electrocardiography was performed. RESULTS: Serious arrhythmias, such as sustained ventricular tachycardia and complete atrioventricular block, were uncommon, but brief episodes of ventricular tachycardia (> or = 3 consecutive ventricular depolarizations) were detected in 4.3% of women and 10.3% of men. Ventricular arrhythmias as a group (excluding ectopic beats < 15/h) were more common in men than in women but were not significantly associated with age. The same patterns were true for bradycardia/conduction blocks. Supraventricular arrhythmias as a group (excluding ectopic beats < 15/h), in contrast, did not differ by gender but were strongly associated with increased age. Multivariate analyses showed associations with arrhythmias to differ by gender, with only one association (increased age and supraventricular arrhythmias) present in both women and men. Ventricular arrhythmias, particularly in men, were associated with a higher prevalence of cardiovascular disease and its risk factors and with subclinical disease, as measured by increased left ventricular mass and impaired left ventricular function. CONCLUSIONS: Arrhythmias are common in the elderly, and their association with cardiovascular disease differs by gender. Although risk related to arrhythmias can only be determined by prospective study, such studies should have adequate power to examine potential gender differences in associations.
Systolic blood pressure response to exercise has been shown to predict development of hypertension in men, but this association has not been examined in population-based samples of men, or in women or non-whites. This relationship was explored in 3741 normotensive black and white young adults undergoing treadmill testing in the CARDIA study and examined 5 years later for development of hypertension. Exaggerated response to exercise (systolic pressure > or = 210 mm Hg in men and > or = 190 mm Hg in women) was detected in 687 subjects (18%) at baseline, and incident hypertension (blood pressure > or = 140/90 mm Hg or on medication) was detected in 184 subjects (4.9%) at followup. Persons with exaggerated response to exercise at baseline had 5 mm Hg higher systolic and 1 mm Hg higher diastolic pressures at follow-up (P < .005) and were 1.70 times more likely to have developed hypertension than were persons with normal response (P < .001). After adjustment for age, race, sex, clinic, resting systolic pressure, body mass index, heavy activity score, exercise duration, and preexercise systolic pressure, exaggerated response was associated with a 2.14 mm Hg increase in year 5 systolic pressure (P < .0001). These associations did not differ by race or sex. Although the increment in systolic pressure associated with exaggerated exercise response was small (1 to 3 mm Hg), this small increment sustained over time could lead to a substantially increased incidence of hypertension and hypertension-related target organ damage. Determination of factors associated with exaggerated response may provide further insights into the development of hypertension in young adults.(ABSTRACT TRUNCATED AT 250 WORDS)
Results from a large number of randomized clinical trials document conclusively that treatment of elevated systolic and/or diastolic blood pressure markedly reduces the risk of cardiovascular complications such as stroke and acute myocardial infarction. Detection, treatment and control of hypertension have major public health implications. A review of the literature suggests the existence of both overtreatment (defined as improper or incorrect diagnosis of hypertension, overaggressive and potentially dangerous blood pressure lowering and the use of expensive antihypertensive drugs with unproven mortality/morbidity benefits) and undertreatment (defined as unrecognized, untreated and poorly controlled hypertension). These current major issues in medicine are discussed.
BACKGROUND AND PURPOSE: Cerebral magnetic resonance imaging often detects abnormalities whose significance is unknown. The prevalence and correlates of findings such as ventricular enlargement, sulcal widening, and increased white matter signal intensity were examined in 303 men and women aged 65 to 95 years participating in a multicenter study of cardiovascular disease. METHODS: Cerebral magnetic resonance imaging was performed and interpreted according to a standard protocol, and findings were correlated with measures of cardiovascular disease and its risk factors. RESULTS: Measures of cerebral atrophy increased with age and were greater in men than in women (each P < .01). Ventricular enlargement and sulcal widening were associated with prior stroke, hypertension, diabetes, and white race (each P < .03). Extent of white matter hyperintensity was associated with age, prior stroke, hypertension, and use of diuretics (each P < .004). On multivariate analysis, age, male gender, white race, and prior stroke retained strong associations with increased ventricular and sulcal scores. After adjustment for age, prior stroke, and other risk factors, white matter hyperintensity was associated with atherosclerosis as measured by increased internal carotid artery thickness on ultrasound. CONCLUSIONS: Cerebral atrophy and white matter hyperintensity are common in the elderly and are associated with age, prior stroke, and known cardiovascular risk factors. Though these findings have been suggested to represent normal aging, their wide variability and associations with cardiovascular disease argue against their inevitability with advancing age and support the need to identify modifiable risk factors for these abnormalities.
Maximal inspiratory pressure (MIP) was assessed in 4,443 ambulatory participants of the Cardiovascular Health Study, 65 yr of age and older, sampled from four communities. Maximal expiratory pressure (MEP) was also measured in 790 participants from a single clinic. Positive predictors of MIP included male sex, FVC, handgrip strength, and higher levels of lean body mass (or low bioelectric resistance). Negative predictors were age, current smoking, self-reported fair to poor general health, and waist size. Both participant and technician learning effects were noted, but there was no independent effect of race, hypertension, cardiovascular disease, or diabetes. A healthy subgroup was identified by excluding current smokers, those with fair to poor general health, or an FEV1 less than 65% of predicted. Mean values determined from the healthy group were 57/116 cm H2O (MIP/MEP) for women, and 83/174 for men. Lower limits of the normal range (fifth percentiles) were 45 to 60% of the mean predicted values. The reference equations derived from this group of healthy 65 to 85-yr-olds may be used by pulmonary function laboratories and respiratory therapists who evaluate the respiratory muscle strength of elderly patients.
PURPOSE: To do a pilot study for the Cardiovascular Health Study (a population-based, longitudinal study of coronary heart disease and stroke in adults 65 years of age and older designed to identify risk factors related to cerebrovascular disease, particularly stroke): (a) to determine the feasibility of adding brain MR to the full-scale study; (b) to evaluate the reliability of standardized MR image interpretation in a multicenter study; and (c) to compare the prevalence of stroke determined by MR with that by clinical history. METHODS: Protocol-defined MR studies were performed in 100 subjects with clinical histories of stroke and 203 subjects without reported histories of stroke. MR scans were independently evaluated by two trained neuroradiologists for the presence of small (< or = 3 mm) and large (> 3 mm) "infarctlike" lesions. The sizes of the cerebral sulci and lateral ventricles and the extent of white matter disease were graded on a scale of 0 to 9. RESULTS: Eighty percent of the Cardiovascular Health Study participants who were invited to undergo MR studies agreed to do so; 95% of those agreeing to the procedure successfully completed the exams. Intrareader and interreader reliability of infarctlike lesion identification was high for large lesions (kappa, 0.71 and 0.78, respectively) but not for small lesions (kappa, 0.71 and 0.32, respectively). Relaxed intrareader and interreader kappa scores for sulcal and ventricular sizes and extent of white matter disease were greater than 0.8 MR evidence of infarctlike lesions was present in 77% of the participants with histories of stroke but was also present in 23% of the participants without clinical histories of stroke. Seventy-nine percent of the infarctlike lesions were larger than 3 mm. CONCLUSIONS: This preliminary study indicates that a large, prospective, epidemiologic study of elderly subjects using MR scans of the brain for identification of cerebrovascular disease is feasible and that the interpretative results are reproducible, and suggests that MR evidence of stroke is more prevalent than reported clinical history of stroke.
Biologic markers have provided a direct method for assessing exposure to environmental tobacco smoke (ETS) and yet few studies have used these techniques to document exposure in general samples of nonsmokers. Exposure to ETS was assessed by serum cotinine and self-report in 3300 nonsmoking participants in the CARDIA study. Nonsmoking status was validated by a cotinine level of < 14 ng/ml. Twenty-eight percent of the 18- to 30-year-olds were exposed to ETS as determined by a detectable serum cotinine level (2-13 ng/ml); prevalence of exposure was higher among blacks than whites (32% vs 24%, P < 0.001). Similarly, ETS exposure as defined by self-report (hours/week) was higher in blacks, particularly for exposure in the home and in other small areas. Multivariate predictors of cotinine-determined exposure included reported exposure, male gender, lower education, past smoking history, and spending time with smokers. Only among current users of marijuana, 20% of the sample, was the black race found to be an independent predictor of exposure. The prevalence of ETS exposure is higher in blacks than whites, as documented by self-report and confirmed by serum cotinine levels. Other correlates of exposure include demographic factors and factors which may be surrogate measures of exposure.
Few large-scale epidemiologic studies have enrolled older adults; hence, little is known about the feasibility of recruiting this group for long-term population-based studies. In this article we present the recruitment experience of the Cardiovascular Health Study (CHS), a population-based, longitudinal study of cardiovascular diseases in adults 65 years and older. Participants were sampled from the Health Care Financing Administration's (HCFA) Medicare eligibility lists in four US communities. Letters were mailed to 11,955 sampled individuals. Persons recruited were required to complete an extensive home interview and then a 4-hour in-clinic examination. Excluded were persons who were expected to be able to complete the baseline examination and who were not expected to return for the 3-year follow-up. Some 3654 participants were recruited from those randomly selected from the Medicare sampling frame. In addition, 1547 other age-eligible persons living in the household with the sampled individuals also participated, yielding a total of 5201 participants. Of those who were contacted, 9.6% were ineligible and 34.9% refused participation. Among those eligible, 38.6% refused and 57.3% were enrolled (the remaining did not refuse but were not enrolled before the recruitment ended). Data from a subsample indicate that compared to those who were ineligible or who refused, enrolled participants were younger, more highly educated, more likely to be married, and less likely to report limitations in activity. Compared to those who were eligible but refused, enrolled participants were less likely to have high blood pressure and stroke and more likely to have quit smoking and to perceive their health status as very good or excellent.(ABSTRACT TRUNCATED AT 250 WORDS)
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BACKGROUND: Low cholesterol levels have been associated with increased mortality from stroke, cancer, and other noncardiovascular diseases, but the reasons for this association remain unclear. One explanation is that persons with low cholesterol levels have early or occult disease that eventually leads to their deaths. METHODS AND RESULTS: This possibility was explored in 2,091 men and 2,714 women 65-100 years old in the Cardiovascular Health Study, a multicenter observational study of risk factors for heart disease and stroke in older adults. Cholesterol levels < or = 160 mg/dL were present in 11.6% of men and 3.7% of women and increased in prevalence with age. After adjustment for age, total cholesterol levels in this range were associated with a twofold increased prevalence of treated diabetes in men and women and with a twofold increased prevalence of cancer diagnosed in the preceding 5 years in women only. Low cholesterol was also associated with lower levels of hemoglobin, albumin, and factor VII, suggesting a link with hepatic synthetic function. On multivariate analysis, factors most strongly associated with low cholesterol levels in men and women were decreased factor VII levels, decreased albumin, and diabetes. CONCLUSIONS: Cross-sectional associations with low cholesterol levels differ by sex and suggest poorer health by some measures. The observed relations with treated diabetes and impaired hepatic synthetic function should be examined for risk of mortality in longitudinal data from this and other observational studies.
BACKGROUND: Peripheral arterial disease measured noninvasively by the ankle-arm index (AAI) is common in older adults, largely asymptomatic, and associated with clinically manifest cardiovascular disease (CVD). The criteria for an abnormal AAI have varied in previous studies. To determine whether there is an inverse dose-response relation between the AAI and clinical CVD, subclinical disease, and risk factors, we examined the relation of the AAI to cardiovascular risk factors, other noninvasive measures of subclinical atherosclerosis using carotid ultrasound, echocardiography and electrocardiography, and clinical CVD. METHODS AND RESULTS: The AAI was measured in 5084 participants > or = 65 years old at the baseline examination of the Cardiovascular Health Study. All subjects had detailed assessment of prevalent CVD, measures of cardiovascular risk factors, and noninvasive measures of disease. Participants were stratified by baseline clinical CVD status and AAI (< 0.8, > or = 0.8 to < 0.9, > or = 0.9 to < 1.0, > or = 1.0 to < 1.5). Analyses tested for a dose-response relation of the AAI with clinical CVD, risk factors, and subclinical disease. The cumulative frequency of a low AAI was 7.4% of participants < 0.8, 12.4% < 0.9, and 23.6% < 1.0. participants with an AAI < 0.8 were more than twice as likely as those with an AAI of 1.0 to 1.5 to have a history of myocardial infarction, angina, congestive heart failure, stroke, or transient ischemic attack (all P < .01). In participants free of clinical CVD at baseline, the AAI was inversely related to history of hypertension, history of diabetes, and smoking, as well as systolic blood pressure, serum creatinine, fasting glucose, fasting insulin, measures of pulmonary function, and fibrinogen level (all P < .01). Risk factor associations with the AAI were similar in men and women free of CVD except for serum total and low-density lipoprotein cholesterol, which were inversely associated with AAI level only in women. Risk factors associated with an AAI of < 1.0 in multivariate analysis included smoking (odds ratio [OR], 2.55), history of diabetes (OR, 3.84), increasing age (OR, 1.54), and nonwhite race (OR, 2.36). In the 3372 participants free of clinical CVD, other noninvasive measures of subclinical CVD, including carotid stenosis by duplex scanning, segmental wall motion abnormalities by echocardiogram, and major ECG abnormalities were inversely related to the AAI (all P < .01). CONCLUSIONS: There was an inverse dose-response relation of the AAI with CVD risk factors and subclinical and clinical CVD among older adults. The lower the AAI, the greater the increase in CVD risk; however, even those with modest, asymptomatic reductions in the AAI (0.8 to 1.0) appear to be at increased risk of CVD.
BACKGROUND: Postmenopausal estrogen replacement therapy has been associated with favorable levels of cardiovascular disease risk factors, but these associations and the relations between estrogen use and subclinical disease have not been examined in large samples of older women. METHODS AND RESULTS: Present and past estrogen use was ascertained in 2955 women > or = 65 years old in the Cardiovascular Health Study, a study of risk factors for coronary heart disease and stroke in the elderly. Present estrogen use was reported by 12% of these women and past use by an additional 26.5%. Estrogen use (past or present) was strongly associated with lower low-density lipoprotein cholesterol, fibrinogen, glucose, insulin, obesity, and age and higher high-density lipoprotein cholesterol and socioeconomic status (all P < .0001). Estrogen users also had lower levels of subclinical disease as measured by carotid intimal-medial thickness, carotid stenosis grade, ECG left ventricular mass, and Doppler mitral peak flow velocities (each P < .02). Relations were similar in younger and older women (65 to 74 versus > or = 75 years) and smokers and nonsmokers and were unchanged after women with poor medication compliance were excluded. After adjustment for other factors, estrogen use was associated with decreased carotid wall thickness, although this association was of borderline significance after further adjustment for lipids. CONCLUSIONS: Postmenopausal estrogen use in this sample of older women was associated with favorable cardiovascular disease risk factor profiles and with lower measures of subclinical disease. These findings suggest that postmenopausal estrogen use may be associated with lower risk of cardiovascular disease in women well into the eighth decade of life.
The random zero sphygmomanometer is widely used in studies involving blood pressure measurement because it is believed to eliminate digit preference and reduce measurement error. We performed blood pressure measurements sequentially using random zero and standard sphygmomanometers in random order in 1,356 participants in the Cardiovascular Health Study. Despite adherence to the manufacturer's instructions, we observed a substantially nonuniform distribution of zero levels generated by the random zero sphygmomanometer and a disturbing correlation between the zero level and blood pressures taken with the standard sphygmomanometer. With the random zero device, the pooled estimated slopes for the regression of standard systolic and diastolic pressures on the zero level were -0.71 and -0.17, respectively (both p < 0.0001). The only plausible explanation for this relation between the random zero device and the standard device is that by some unknown mechanism the subject's blood pressure is influencing the zero level. Systolic and diastolic blood pressures measured with the random zero device were, respectively, 1.65 and 1.84 mm Hg lower (both p < 0.0001) than standard blood pressures. Digit preference was detectable in the uncorrected blood pressure and zero level measured with the random zero device but was eliminated after calculation of the corrected blood pressure. For most epidemiological studies, the random zero sphygmomanometer offers no significant advantage over the standard sphygmomanometer. It may still be useful in those epidemiological studies and clinical trials where blinding is important.
Hostility has been associated with coronary heart disease mortality. To assess possible mechanisms linking hostility to coronary heart disease risk, the authors conducted analyses in a cross-sectional study from data collected in 1985 and 1986 on 5,115 young adults, aged 18-30 years, black and white, male and female, in four large urban areas of the United States. The results show that higher levels of hostility as determined by the Cook-Medley Hostility Scale were strongly associated with tobacco and marijuana smoking, increased alcohol consumption, and greater caloric intake in both blacks and whites and in both men and women. The increased caloric consumption was evident in the higher waist/hip ratios, particularly in men (p less than 0.05). The associations were particularly strong (p less than 0.001) for tobacco cigarette smoking and marijuana smoking, with roughly a 1.5 times higher prevalence in the top hostility quartile compared with the bottom quartile after adjusting for age and education. Hostility levels were not related to the percentage of calories from fat or from sucrose intake, to plasma cholesterol levels, or to physical fitness (except for a weak association in the latter in white women). The results describe relations between hostility and health behaviors that may be detrimental to health. The findings provide a possible explanation for the association between hostility and coronary heart disease mortality.
Idiopathic dilated cardiomyopathy (IDC) is the primary indication for cardiac transplantation, with associated costs of approximately $177 million per year. Recognizing the economic implications of IDC, the increasing incidence, and the limited information on pathogenesis and prognosis, the National Heart, Lung, and Blood Institute convened a workshop on the Prevalence and Etiology of Idiopathic Dilated Cardiomyopathy on June 13 to 14, 1991. The difficulties of studying the disease were reviewed, including its relatively low prevalence, its potentially pluricausal nature, and the fact that it is often a diagnosis of exclusion. Still, it presents significant challenges to the cardiovascular scientific community, since the mechanism of myocardial damage and related etiologic and prognostic factors are virtually unknown. The development of more reliable measures of immune-mediated damage and noninvasive measures of impaired cardiac function present new research opportunities in this disorder. Standardized diagnostic criteria for use in observational and interventional trials were developed, and priorities for future research were proposed. Population-based registries and nested case-control studies, where feasible, are appropriate study designs for tracking incidence and prevalence, and for identifying risk factors, respectively. Interventional studies should focus on secondary prevention, through modifying immune-mediated damage in clinically evident dilated cardiomyopathy, and through prevention of sudden death in patients with the disorder. Primary prevention trials must await the identification of modifiable risk factors and of appropriate and effective interventions.
Electrocardiographic abnormalities are often found in older patients, but their prevalence in free-living elderly populations is not well-defined. In addition, the clinical significance of many of these abnormalities is uncertain. The prevalence of major electrocardiographic abnormalities was determined in 5,150 adults aged greater than or equal to 65 years from the Cardiovascular Health Study--a study of risk factors for stroke and coronary heart disease in the elderly. Ventricular conduction defects, major Q/QS waves, left ventricular hypertrophy, isolated major ST-T-wave abnormalities, atrial fibrillation and first-degree atrioventricular block were collectively categorized as major electrocardiographic abnormalities. Prevalence of any major electrocardiographic abnormality was 29% in the entire cohort, 19% among 2,413 participants who reported no history of coronary artery disease or systemic hypertension, and 37% among 2,737 participants with a history of coronary artery disease or hypertension. Prevalence of major electrocardiographic abnormalities was higher in men than in women regardless of history, and tended to increase with age. Major Q/QS waves were found in 5.2%, and more than half were in those who did not report a previous myocardial infarction. Major electrocardiographic abnormalities are common in elderly men and women irrespective of the history of heart disease.
OBJECTIVES: To assess the proportion of community-dwelling adults aged 65 years or older who are eligible for referral for lipoprotein analysis and intervention according to the National Cholesterol Education Program (NCEP) guidelines. DESIGN: Cross-sectional study based on examinations and questionnaires collected in 1989 and 1990. SETTING: Four communities in the U.S. in the Cardiovascular Health Study (CHS), a study of risk factors for heart disease and stroke in older adults. PARTICIPANTS: A sample of 4810 men and women ages 65 to 100 randomly selected and recruited from Health Care Financing Administration Medicare eligibility lists for the four communities; not institutionalized, not wheelchair-bound, not currently receiving therapy for cancer, not currently taking lipid-lowering medications, and not having eaten in the preceding 9 hours. MEASUREMENTS: Total cholesterol and lipoprotein analysis measured in all participants. RESULTS: Total cholesterol levels were less than 5.17 mmol/L (200 mg/dL) in 37% of participants, 5.17 to 6.19 mmol/L (200 to 239 mg/dL) in 39%, and 6.20 mmol/L (240 mg/dL) or greater in 24%. Compared with their counterparts, older participants, especially those over 80 years of age, were more likely to have levels below 5.17 mmol/L, as were men, nonwhites, and those with coronary heart disease or two or more coronary heart disease risk factors (P less than 0.008 for all values). Based on this screening measurement, 2174 participants were eligible for lipoprotein analysis, 80% were eligible for dietary or drug therapy using NCEP guidelines. Overall, 46% of CHS participants were eligible for lipoprotein analysis and 36% for intervention by NCEP guidelines, based on a single cholesterol measurement. CONCLUSION: A substantial proportion of older adults in this community sample were eligible for lipoprotein analysis and intervention. Prospective studies of elderly persons are needed to determine the risk for incident coronary heart disease according to NCEP classifications and the benefits of lipid-lowering treatments in persons in this age group so that intervention strategies may best be targeted to an appropriately high-risk group.