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Biomedical subjects

E J Benjamin

Publications and source records attributed to E J Benjamin.

At least 37 records · Page 2Linked to original sources
PubMed1998

Prevalence, incidence, prognosis, and predisposing conditions for atrial fibrillation: population-based estimates.

Atrial fibrillation (AF) is the most common of the serious cardiac rhythm disturbances and is responsible for substantial morbidity and mortality in the general population. Its prevalence doubles with each advancing decade of age, from 0.5% at age 50-59 years to almost 9% at age 80-89 years. It is also becoming more prevalent, increasing in men aged 65-84 years from 3.2% in 1968-1970 to 9.1% in 1987-1989. This statistically significant increase in men was not explained by an increase in age, valve disease, or myocardial infarctions in the cohort. The incidence of new onset of AF also doubled with each decade of age, independent of the increasing prevalence of known predisposing conditions. Based on 38-year follow-up data from the Framingham Study, men had a 1.5-fold greater risk of developing AF than women after adjustment for age and predisposing conditions. Of the cardiovascular risk factors, only hypertension and diabetes were significant independent predictors of AF, adjusting for age and other predisposing conditions. Cigarette smoking was a significant risk factor in women adjusting only for age (OR = 1.4), but was just short of significance on adjustment for other risk factors. Neither obesity nor alcohol intake was associated with AF incidence in either sex. For men and women, respectively, diabetes conferred a 1.4- and 1.6-fold risk, and hypertension a 1.5- and 1.4-fold risk, after adjusting for other associated conditions. Because of its high prevalence in the population, hypertension was responsible for more AF in the population (14%) than any other risk factor. Intrinsic overt cardiac conditions imposed a substantially higher risk. Adjusting for other relevant conditions, heart failure was associated with a 4.5- and 5.9-fold risk, and valvular heart disease a 1.8- and 3.4-fold risk for AF in men and women, respectively. Myocardial infarction significantly increased the risk factor-adjusted likelihood of AF by 40% in men only. Echocardiographic predictors of nonrheumatic AF include left atrial enlargement (39%/ increase in risk per 5-mm increment), left ventricular fractional shortening (34% per 5% decrement), and left ventricular wall thickness (28% per 4-mm increment). These echocardiographic features offer prognostic information for AF beyond the traditional clinical risk factors. Electrocardiographic left ventricular hypertrophy increased risk of AF 3-4-fold after adjusting only for age, but this risk ratio is decreased to 1.4 after adjustment for the other associated conditions. The chief hazard of AF is stroke, the risk of which is increased 4-5-fold. Because of its high prevalence in advanced age, AF assumes great importance as a risk factor for stroke and by the ninth decade becomes a dominant factor. The attributable risk for stroke associated with AF increases steeply from 1.5% at age 50-59 years to 23.5% at age 80-89 years. AF is associated with a doubling of mortality in both sexes, which is decreased to 1.5-1.9-fold after adjusting for associated cardiovascular conditions. Decreased survival associated with AF occurs across a wide range of ages.

Aged↗
PubMed1998

Impact of atrial fibrillation on the risk of death: the Framingham Heart Study.

BACKGROUND: Atrial fibrillation (AF) causes substantial morbidity. It is uncertain whether AF is associated with excess mortality independent of associated cardiac conditions and risk factors. METHODS AND RESULTS: We examined the mortality of subjects 55 to 94 years of age who developed AF during 40 years of follow-up of the original Framingham Heart Study cohort. Of the original 5209 subjects, 296 men and 325 women (mean ages, 74 and 76 years, respectively) developed AF and met eligibility criteria. By pooled logistic regression, after adjustment for age, hypertension, smoking, diabetes, left ventricular hypertrophy, myocardial infarction, congestive heart failure, valvular heart disease, and stroke or transient ischemic attack, AF was associated with an OR for death of 1.5 (95% CI, 1.2 to 1.8) in men and 1.9 (95% CI, 1.5 to 2.2) in women. The risk of mortality conferred by AF did not significantly vary by age. However, there was a significant AF-sex interaction: AF diminished the female advantage in survival. In secondary multivariate analyses, in subjects free of valvular heart disease and preexisting cardiovascular disease, AF remained significantly associated with excess mortality, with about a doubling of mortality in both sexes. CONCLUSIONS: In subjects from the original cohort of the Framingham Heart Study, AF was associated with a 1.5- to 1.9-fold mortality risk after adjustment for the preexisting cardiovascular conditions with which AF was related. The decreased survival seen with AF was present in men and women and across a wide range of ages.

Adult↗
PubMed1998

Increased left ventricular mass and hypertrophy are associated with increased risk for sudden death.

OBJECTIVES: This study examined the relations of echocardiographically determined left ventricular (LV) mass and hypertrophy to the risk of sudden death. BACKGROUND: Echocardiographic LV hypertrophy is associated with increased risk for all-cause mortality and cardiovascular disease morbidity and mortality. However, little is known about the association of echocardiographic LV hypertrophy with sudden death. METHODS: We examined the relations of LV mass and hypertrophy to the incidence of sudden death in 3,661 subjects enrolled in the Framingham Heart Study who were > or =40 years of age. The baseline examination was performed from 1979 to 1983 and LV hypertrophy was defined as LV mass (adjusted for height) > 143 g/m in men and > 102 g/m in women. During up to 14 years of follow-up there were 60 sudden deaths. Cox models examined the relations of LV mass and LV hypertrophy to sudden death risk after adjusting for known risk factors. RESULTS: The prevalence of LV hypertrophy was 21.5%. The risk factor-adjusted hazard ratio (HR) for sudden death was 1.45 (95% confidence interval [CI] 1.10 to 1.92, p=0.008) for each 50-g/m increment in LV mass. For LV hypertrophy, the risk factor-adjusted HR for sudden death was 2.16 (95% CI 1.22 to 3.81, p=0.008). After excluding the first 4 years of follow-up, both increased LV mass and LV hypertrophy conferred long-term risk of sudden death (HR 1.53, 95% CI 1.01 to 2.28, p=0.047 and HR 3.28, 95% CI 1.58 to 6.83, p=0.002, respectively). CONCLUSIONS: Increased LV mass and hypertrophy are associated with increased risk for sudden death after accounting for known risk factors.

Adult↗
PubMed1998

Non-invasive assessment of brachial artery endothelial vasomotor function: the effect of cuff position on level of discomfort and vasomotor responses.

Non-invasive assessment of brachial artery flow-mediated dilation using cuff occlusion of the arm above or below the elbow to stimulate flow is emerging as a highly useful technique to examine endothelial vasomotor function in human subjects. In anticipation of a large-scale investigation, an important issue is the acceptability of the technique to participants. The purpose of this study was to determine the level of discomfort associated with the technique and compare it to the commonly used procedure of venipuncture. Flow-mediated dilation was determined using cuff occlusion of the arm above the elbow and a blood sample was obtained by standard venipuncture from 54 subjects. The level of discomfort for each procedure was assessed and compared using a visual analogue scale and was found to be extremely low. When the occlusion cuff was positioned above the elbow, the discomfort was slightly more severe (1.9+/-1.9 cm) than venipuncture (1.0+/-1.3 cm, p = 0.003). In 27 subjects, the effect of cuff position (above or below the elbow) was compared: the below the elbow position was associated with a reduction in the percentage increase in flow (570+/-280% versus 900+/-560%, p = 0.005), flow-mediated dilation (6.8+/-3.8% versus 9.8+/-5.7%, p = 0.008) and discomfort (1.6+/-0.8 versus 3.7+/-2.2 cm, p = 0.008). When the cuff was located below the elbow, the level of discomfort was equivalent to that associated with venipuncture. Thus, non-invasive assessment of flow-mediated brachial artery dilation is well tolerated and appears to be suitable for a large-scale study of endothelial function.

Adult↗
PubMed1997

Distribution and categorization of echocardiographic measurements in relation to reference limits: the Framingham Heart Study: formulation of a height- and sex-specific classification and its prospective validation.

BACKGROUND: Despite widespread categorization of echocardiographic measurements, there are no standardized guidelines for partitioning values exceeding reference limits. METHODS AND RESULTS: We used regression analyses to develop sex- and height-specific reference limits for cardiac M-mode measurements (left ventricular [LV] mass, LV wall thickness, and LV and left atrial dimensions) in a healthy reference sample (n=1099) from the Framingham Heart Study. We then examined the distribution of measurements in a broad sample (n=4957) and classified the measurements according to increasing deviation from the height- and sex-specific reference limits and the 95th, 98th, and 99th percentile values for the broad sample (categories 0 through 4, respectively). To validate the categorization scheme, we used multivariable proportional-hazards regression to assess the relations of LV mass and LV wall thickness categories to risk of cardiovascular events and the relations of left atrial size to risk of atrial fibrillation. During a mean follow-up period of 7.7 years, 587 subjects developed new cardiovascular disease events, and 166 subjects developed new-onset atrial fibrillation. After adjustment for known risk factors, there was a 1.2- and 1.3-fold risk of cardiovascular disease events per category of LV wall thickness and LV mass, respectively, and a 1.6-fold risk of atrial fibrillation per category of left atrial size. CONCLUSIONS: Using a large community-based study sample, we propose a classification scheme that provides a standardized and validated framework for partitioning echocardiographic measurements. If adopted, the categorization scheme should promote uniformity in describing measurements among echocardiographic laboratories and enhance the comprehensibility of measurements to clinicians.

Adolescent↗
PubMed1997

Left ventricular dilatation and the risk of congestive heart failure in people without myocardial infarction.

BACKGROUND: Left ventricular dilatation is a well-recognized precursor of ventricular dysfunction and congestive heart failure after myocardial infarction. The effect of left ventricular dilatation on the risk of heart failure in people initially free of myocardial infarction is not known. METHODS: We examined the relation of the left ventricular end-diastolic and end-systolic internal dimensions, as measured by M-mode echocardiography, to the risk of congestive heart failure in 4744 subjects (2083 men and 2661 women) who had not sustained a myocardial infarction and who were free of congestive heart failure. We used sex-stratified proportional-hazards regression to assess the association between base-line left ventricular internal dimensions and the subsequent risk of congestive heart failure, after adjusting for age, blood pressure, hypertension treatment, body-mass index, diabetes, valve disease, and interim myocardial infarction. RESULTS: Over an 11-year follow-up period, congestive heart failure developed in 74 subjects (38 men and 36 women). The risk-factor-adjusted hazard ratio for congestive heart failure was 1.47 (95 percent confidence interval, 1.25 to 1.73) for an increment of 1 SD in the left ventricular end-diastolic dimension, indexed for height. We obtained similar results using the left ventricular end-systolic dimension (hazard ratio, 1.43; 95 percent confidence interval, 1.24 to 1.65). CONCLUSIONS: An increase in left ventricular internal dimension is a risk factor for congestive heart failure in men and women who have not had a myocardial infarction. Knowledge of the left ventricular dimension improves predictions of the risk of congestive heart failure made on the basis of traditional risk factors, perhaps by aiding in the identification of subjects with subclinical left ventricular dysfunction.

Female↗
PubMed1996

Congestive heart failure with normal left ventricular systolic function. Clinical approaches to the diagnosis and treatment of diastolic heart failure.

The syndrome of congestive heart failure with preserved left ventricular systolic function is common in clinical practice. The signs and symptoms of the disorder are similar to those of congestive heart failure with left ventricular systolic dysfunction, underscoring a need for routine evaluation of left and right ventricular systolic function in patients with congestive heart failure. The syndrome may be related to anatomic abnormalities that increase the resistance to ventricular filling, or to physiologic abnormalities of myocardial relaxation or compliance. Advancing age, often in association with hypertension, coronary artery disease, tachycardia, and atrial fibrillation, is commonly associated with the disorder. Randomized controlled clinical trials are needed to evaluate the efficacy of various therapeutic agents in reducing the risks associated with diastolic heart failure.

Algorithms↗
PubMed1996

Doppler diastolic filling indexes in relation to disease states.

This study compares mean Doppler-derived diastolic filling indexes in a variety of disease states in a large, population-based sample. Pulse-wave Doppler was used to examine 880 eligible participants of the Framingham Heart Study. Peak velocity of early flow and late flow, ratio of early to late peak velocities, atrial filling fraction, and early filling wave acceleration and deceleration times were obtained. Multiple linear regression analyses were performed comparing mean values for individuals with hypertension, diabetes, coronary disease, cardiovascular disease, and pulmonary disease. Hypertension was associated with a greater peak velocity late flow (0.027 m/sec; 95% confidence interval, 0.006, 0.047; p = 0.011), and diabetes was associated with a larger mean deceleration time (0.12 sec, confidence interval, 0.002, 0.021; p = 0.016). In multivariate analyses, hypertension continued to show a strong association with altered Doppler diastolic filling patterns, p value 0.009, whereas in diabetes, the multivariate p value was 0.28.

Adult↗
PubMed1996

Stroke severity in atrial fibrillation. The Framingham Study.

BACKGROUND AND PURPOSE: Stroke occurring with atrial fibrillation (AF) is more likely to be fatal or more severe than non-AF stroke based on clinical series, but data from prospective epidemiological studies are sparse and inconsistent. METHODS: Over 40-year follow-up of the original 5070 Framingham cohort, 501 initial ischemic strokes, including 103 with AF, were analyzed. Stroke severity was rated as none, mild, moderate, severe, or fatal. Since 1981, functional status indicated by the Barthel index has been evaluated acutely and at 3, 6, and 12 months. Severity and functional status of AF strokes were compared with non-AF strokes using chi 2 test and Student's t test. Thirty-day mortality was assessed by logistic regression analyses. RESULTS: AF was associated with increased stroke severity (P = .048). Thirty-day mortality was greater in AF strokes than in non-AF strokes (25% versus 14%). The multivariate-adjusted odds ratio for 30-day mortality for AF subjects was 1.84 (95% confidence interval, 1.04 to 3.27). Since 1981, follow-up was available for 150 initial ischemic strokes, including 30 with AF. Compared with the non-AF group, the AF group had poorer survival and more recurrences during 1 year of follow-up. The AF subjects had lower mean Barthel index scores acutely (29.6 versus 58.6, P < .001) and at 3 months (P = .005), 6 months (P = .003), and 12 months (P = .130) after stroke among survivors. CONCLUSIONS: Ischemic stroke associated with AF was nearly twice as likely to be fatal as non-AF stroke. Recurrence was more frequent, and functional deficits were more likely to be severe among survivors. Since stroke is usually the initial manifestation of embolism in AF, prevention is critical to reducing disability and mortality.

Adult↗
PubMed1995

Left atrial size and the risk of stroke and death. The Framingham Heart Study.

BACKGROUND: The medical literature contains conflicting reports on the association of left atrial (LA) enlargement with risk of stroke. The relation of LA size to risk of stroke and death in the general population remains largely unexplored. METHODS AND RESULTS: Subjects 50 years of age and older from the Framingham Heart Study were studied to assess the relations between echocardiographic LA size and risk of stroke and death. During 8 years of follow-up, 64 of 1371 (4.7%) men and 73 of 1728 (4.2%) women sustained a stroke, and 296 (21.6%) men and 271 (15.7%) women died. Sex-specific Cox proportional-hazards models were adjusted for age, hypertension, diabetes, atrial fibrillation, smoking, ECG left ventricular (LV) hypertrophy, and congestive heart failure or myocardial infarction. After multivariable adjustment, for every 10-mm increase in LA size, the relative risk of stroke was 2.4 in men (95% CI, 1.6 to 3.7) and 1.4 in women (95% CI, 0.9 to 2.1); the relative risk of death was 1.3 in men (95% CI, 1.0 to 1.5) and 1.4 in women (95% CI, 1.1 to 1.7). Adjusting for ECG LV mass/height attenuated the relation of LA size to stroke and death. CONCLUSIONS: After multivariable adjustment, LA enlargement remained a significant predictor of stroke in men and death in both sexes. The relation of LA enlargement to stroke and death appears to be partially mediated by LV mass.

Aged↗
PubMed1995

Prevalence, clinical features and prognosis of diastolic heart failure: an epidemiologic perspective.

Numerous reports suggest that about one-third of patients with congestive heart failure do not have any abnormality of left ventricular systolic function. These patients presumably have heart failure on the basis of ventricular diastolic dysfunction. Our objective was to develop a comprehensive overview of published reports of the prevalence, clinical features and prognosis of diastolic heart failure and to offer recommendations for future studies. Thirty-one studies of patients with congestive heart failure with normal left ventricular systolic function were published in the time period from January 1970 through March 1995. These studies were identified with the use of computer-based searches in relevant data bases. Among patients with congestive heart failure, the prevalence of normal ventricular systolic performance in the published reports varies widely from 13% to 74%; the reported annual mortality rate also varies from 1.3% to 17.5%. The criteria for congestive heart failure, its chronicity and the age of the study sample affect the reported prevalence and prognosis of the disorder. The clinical signs and symptoms of diastolic heart failure are similar to those of patients with systolic heart failure, underscoring the need for evaluation of ventricular systolic function in patients with congestive heart failure. In the absence of any large-scale randomized clinical trial targeting these patients, the optimal treatment of diastolic heart failure is unclear. We conclude that the heterogeneity in previous studies of diastolic heart failure hinders the comparison of published reports. There is a need to conduct prospective, community-based investigations to better characterize the incidence, prevalence and natural history of diastolic heart failure. Randomized clinical trials are needed to determine optimal treatment strategies.

Diastole↗
PubMed1995

Influence of blood pressure on left atrial size. The Framingham Heart Study.

Increased left atrial size has been identified as a precursor of atrial fibrillation and of stroke once atrial fibrillation is manifest. Conflicting data exist regarding the effect of high blood pressure on left atrial size. Our objective was to evaluate the association of contemporary and long-term measures of blood pressure with echocardiographically determined left atrial size in a large, population-based cohort. The study sample consisted of 1849 male and 2152 female participants of the Framingham Heart Study and Framingham Offspring Study. All analyses were sex specific. In correlation analyses, systolic and pulse pressures were identified as statistically significant determinants of left atrial size after adjustment for age and body mass index, although the magnitudes of these relations were very modest (partial r < or = .10). Multivariable linear regression models showed the relative contributions of the pressure variables to the prediction of left atrial size to be substantially less than those of age and, in particular, body mass index. Furthermore, inclusion of left ventricular mass in these multivariable models eliminated or attenuated the associations of the pressure variables with left atrial size. In logistic analyses, increasing levels of the pressure variables were significantly predictive of left atrial enlargement. Subjects with 8-year average systolic pressure of 140 mm Hg or higher were twice as likely to have left atrial enlargement as those with values of 110 mm Hg or lower. Overall, in this population-based study sample, increased levels of systolic and pulse pressures (but not diastolic or mean arterial pressures) were significantly associated with increased left atrial size.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Newly diagnosed atrial fibrillation and acute stroke. The Framingham Study.

BACKGROUND AND PURPOSE: When atrial fibrillation (AF) is first documented at the time of onset of acute stroke, it is difficult to establish a temporal relationship between AF and stroke. Did AF precede and precipitate the stroke, or did the arrhythmia appear as a result of stroke? Following the course of the newly diagnosed AF may help to clarify this relationship. METHODS: The Framingham Study cohort of 5070 members, aged 30 to 62 years and free of cardiovascular disease at entry, has been under surveillance for the development of cardiovascular disease, including stroke. We followed the course of AF, which was documented for the first time on or soon after hospital admission for stroke. RESULTS: During 38 years of follow-up, 115 of 656 initial stroke events occurred in association with AF: 89 had previously documented AF, 21 had AF discovered for the first time on admission for the stroke, and 5 were admitted with sinus rhythm but developed AF after admission. Of the 21 subjects with AF diagnosed on admission, in 12 (57%) AF persisted thereafter (chronic AF). Among the other 9 persons presenting with nonpersistant AF, paroxysms recurred in 3 (14%) and became chronic AF in 4 (19%). AF was transient and did not recur in only 2 persons (10%). Of the 5 subjects who developed AF after admission, AF was sustained from the initial diagnosis in 2 and recurred in paroxysms or became established as chronic in 3. CONCLUSIONS: Ninety-two percent (24/26) of subjects presenting with newly discovered AF at the time of acute stroke continued to have this rhythm disturbance in a chronic or paroxysmal form. In only 2 subjects (8%) was the arrhythmia short-lived and nonrecurrent. These follow-up data suggest that in most instances AF was probably the precipitant rather than the consequence of stroke.

Acute Disease↗
PubMed1994

Low serum thyrotropin concentrations as a risk factor for atrial fibrillation in older persons.

BACKGROUND: Low serum thyrotropin concentrations are a sensitive indicator of hyperthyroidism but can also occur in persons who have no clinical manifestations of the disorder. We studied whether low serum thyrotropin concentrations in clinically euthyroid older persons are a risk factor for subsequent atrial fibrillation. METHODS: We studied 2007 persons (814 men and 1193 women) 60 years of age or older who did not have atrial fibrillation in order to determine the frequency of this arrhythmia during a 10-year follow-up period. The subjects were classified according to their serum thyrotropin concentrations: those with low values (< or = 0.1 mU per liter; 61 subjects); those with slightly low values (> 0.1 to 0.4 mU per liter; 187 subjects); those with normal values (> 0.4 to 5.0 mU per liter; 1576 subjects); and those with high values (> 5.0 mU per liter; 183 subjects). RESULTS: During the 10-year follow-up period, atrial fibrillation occurred in 13 persons with low initial values for serum thyrotropin, 23 with slightly low values, 133 with normal values, and 23 with high values. The cumulative incidence of atrial fibrillation at 10 years was 28 percent among the subjects with low serum thyrotropin values (< or = 0.1 mU per liter), as compared with 11 percent among those with normal values; the age-adjusted incidence of atrial fibrillation was 28 per 1000 person-years among those with low values and 10 per 1000 person-years among those with normal values (P = 0.005). After adjustment for other known risk factors, the relative risk of atrial fibrillation in elderly subjects with low serum thyrotropin concentrations, as compared with those with normal concentrations, was 3.1 (95 percent confidence interval, 1.7 to 5.5; P < 0.001). The 10-year incidence of atrial fibrillation in the groups with slightly low and high serum thyrotropin values was not significantly different from that in the group with normal values. CONCLUSIONS: Among people 60 years of age or older, a low serum thyrotropin concentration is associated with a threefold higher risk that atrial fibrillation will develop in the subsequent decade.

Age Factors↗
PubMed1994

Left ventricular mass and risk of stroke in an elderly cohort. The Framingham Heart Study.

OBJECTIVE: To evaluate the association of echocardiographically determined left ventricular mass (LVM) with incidence of stroke or transient ischemic attack in an elderly cohort. DESIGN: Cohort study with a follow-up period of 8 years. SETTING: Population-based sample. SUBJECTS: Elderly original cohort subjects of the Framingham Heart Study who were free of cerebrovascular disease and atrial fibrillation at the 16th biennial examination and who had adequate echocardiograms. This group consisted of 447 men (mean age, 67.8 years; range, 60 to 90 years) and 783 women (mean age, 69.2 years; range 59 to 90 years). MAIN OUTCOME MEASURES: Age-adjusted 8-year incidence of stroke was examined as a function of baseline quartiles of LVM-to-height ratio. Proportional hazards regression was used in multivariate analyses to assess risk of stroke as a function of LVM-to-height ratio quartile, adjusting for age, sex, systolic blood pressure, hypertension treatment, diabetes, cigarette smoking, and blood lipid levels. RESULTS: Among the 1230 subjects eligible, 89 cerebrovascular disease events (62 strokes and 27 transient ischemic attacks) occurred during follow-up. In men, 8-year age-adjusted incidence of cerebrovascular events was 18.4% in the highest quartile of LVM-to-height ratio and 5.2% in the lowest quartile. Corresponding values in women were 12.2% and 2.9%. The hazard ratio for cerebrovascular events comparing highest to lowest quartile of LVM-to-height ratio was 2.72 (95% confidence interval [CI], 1.39 to 5.36) after adjusting for age, sex, systolic blood pressure, hypertension treatment, diabetes, cigarette smoking, and the ratio of total cholesterol to high-density lipoprotein cholesterol. After adjusting for age, sex, and cardiovascular disease risk factors, the hazard ratio for cerebrovascular events was 1.45 (95% CI, 1.17 to 1.80) for each quartile increment of LVM-to-height ratio. CONCLUSIONS: Echocardiographically determined LVM-to-height ratio offers prognostic information beyond that provided by traditional cerebrovascular disease risk factors. Echocardiography provides information that facilitates identification of individuals at high risk for stroke and transient ischemic attack.

Aged↗