Philip A. Wolf

Atrial fibrillation as an independent risk factor for stroke: the Framingham Study.

The impact of nonrheumatic atrial fibrillation, hypertension, coronary heart disease, and cardiac failure on stroke incidence was examined in 5,070 participants in the Framingham Study after 34 years of follow-up. Compared with subjects free of these conditions, the age-adjusted incidence of stroke was more than doubled in the presence of coronary heart disease (p less than 0.001) and more than trebled in the presence of hypertension (p less than 0.001). There was a more than fourfold excess of stroke in subjects with cardiac failure (p less than 0.001) and a near fivefold excess when atrial fibrillation was present (p less than 0.001). In persons with coronary heart disease or cardiac failure, atrial fibrillation doubled the stroke risk in men and trebled the risk in women. With increasing age the effects of hypertension, coronary heart disease, and cardiac failure on the risk of stroke became progressively weaker (p less than 0.05). Advancing age, however, did not reduce the significant impact of atrial fibrillation. For persons aged 80-89 years, atrial fibrillation was the sole cardiovascular condition to exert an independent effect on stroke incidence (p less than 0.001). The attributable risk of stroke for all cardiovascular contributors decreased with age except for atrial fibrillation, for which the attributable risk increased significantly (p less than 0.01), rising from 1.5% for those aged 50-59 years to 23.5% for those aged 80-89 years. While these findings highlight the impact of each cardiovascular condition on the risk of stroke, the data suggest that the elderly are particularly vulnerable to stroke when atrial fibrillation is present.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

General Cardiovascular Risk Profile for Use in Primary Care The Framingham Heart Study

Background— Separate multivariable risk algorithms are commonly used to assess risk of specific atherosclerotic cardiovascular disease (CVD) events, ie, coronary heart disease, cerebrovascular disease, peripheral vascular disease, and heart failure. The present report presents a single multivariable risk function that predicts risk of developing all CVD and of its constituents. Methods and Results— We used Cox proportional-hazards regression to evaluate the risk of developing a first CVD event in 8491 Framingham study participants (mean age, 49 years; 4522 women) who attended a routine examination between 30 and 74 years of age and were free of CVD. Sex-specific multivariable risk functions (“general CVD” algorithms) were derived that incorporated age, total and high-density lipoprotein cholesterol, systolic blood pressure, treatment for hypertension, smoking, and diabetes status. We assessed the performance of the general CVD algorithms for predicting individual CVD events (coronary heart disease, stroke, peripheral artery disease, or heart failure). Over 12 years of follow-up, 1174 participants (456 women) developed a first CVD event. All traditional risk factors evaluated predicted CVD risk (multivariable-adjusted P<0.0001). The general CVD algorithm demonstrated good discrimination (C statistic, 0.763 [men] and 0.793 [women]) and calibration. Simple adjustments to the general CVD risk algorithms allowed estimation of the risks of each CVD component. Two simple risk scores are presented, 1 based on all traditional risk factors and the other based on non-laboratory-based predictors. Conclusions— A sex-specific multivariable risk factor algorithm can be conveniently used to assess general CVD risk and risk of individual CVD events (coronary, cerebrovascular, and peripheral arterial disease and heart failure). The estimated absolute CVD event rates can be used to quantify risk and to guide preventive care.

Heart Disease and Stroke Statistics—2006 Update

1. About These Statistics 2. Cardiovascular Diseases 3. Coronary Heart Disease, Acute Coronary Syndrome and Angina Pectoris 4. Stroke and Stroke in Children 5. High Blood Pressure (and End-Stage Renal Disease) 6. Congenital Cardiovascular Defects 7. Heart Failure 8. Other Cardiovascular Diseases 9. Risk Factors 10. Metabolic Syndrome 11. Nutrition 12. Quality of Care 13. Medical Procedures 14. Economic Cost of Cardiovascular Diseases 15. At-a-Glance Summary Tables 16. Glossary and Abbreviation Guide 17. Acknowledgment 18. References Appendix I: List of Statistical Fact Sheets. URL: http://www.americanheart.org/presenter.jhtml?identifier=2007 The American Heart Association works with the Centers for Disease Control and Prevention’s National Center for Health Statistics (CDC/NCHS), the National Heart, Lung, and Blood Institute (NHLBI), the National Institute of Neurological Disorders and Stroke (NINDS), and other government agencies to derive the annual statistics in this update. This section describes the most important sources we use. For more details and an alphabetical list of abbreviations, see the Glossary and Abbreviation Guide. All statistics are for the most recent year available. Prevalence, mortality and hospitalizations are computed for 2003 unless otherwise noted. Mortality as an underlying or contributing cause of death is for 2002. Economic cost estimates are for 2006. Due to late release of data, some disease mortality are not updated to 2003. Mortality for 2003 are underlying preliminary data, obtained from the NCHS publication National Vital Statistics Report: Deaths: Preliminary Data for 2003 (NVSR, 2005;53:15) and from unpublished tabulations furnished by Robert Anderson of NCHS. US and state death rates and prevalence rates are age-adjusted per 100 000 population (unless otherwise specified) using the 2000 …

Lifetime Risk for Development of Atrial Fibrillation The Framingham Heart Study

Background—Atrial fibrillation (AF) is the most common cardiac dysrhythmia and a source of considerable morbidity and mortality, but lifetime risk for AF has not been estimated. Methods and Results—We included all participants in the Framingham Heart Study who were free of AF at index ages of 40 years and older. We estimated lifetime risks for AF (including atrial flutter) to age 95 years, with death free of AF as a competing event. We followed 3999 men and 4726 women from 1968 to 1999 (176 166 person-years); 936 participants had development of AF and 2621 died without prior AF. At age 40 years, lifetime risks for AF were 26.0% (95% CI, 24.0% to 27.0%) for men and 23.0% (21.0% to 24.0%) for women. Lifetime risks did not change substantially with increasing index age despite decreasing remaining years of life because AF incidence rose rapidly with advancing age. At age 80 years, lifetime risks for AF were 22.7% (20.1% to 24.1%) in men and 21.6% (19.3% to 22.7%) in women. In further analyses, counting only those who had development of AF without prior or concurrent congestive heart failure or myocardial infarction, lifetime risks for AF were approximately 16%. Conclusions—Lifetime risks for development of AF are 1 in 4 for men and women 40 years of age and older. Lifetime risks for AF are high (1 in 6), even in the absence of antecedent congestive heart failure or myocardial infarction. These substantial lifetime risks underscore the major public health burden posed by AF and the need for further investigation into predisposing conditions, preventive strategies, and more effective therapies.

Prevalence, incidence, prognosis, and predisposing conditions for atrial fibrillation: population-based estimates 1

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.

Temporal Relations of Atrial Fibrillation and Congestive Heart Failure and Their Joint Influence on Mortality: The Framingham Heart Study

Background Atrial fibrillation (AF) and congestive heart failure (CHF) frequently occur together, but there is limited information regarding their temporal relations and the combined influence of these conditions on mortality. Methods and Results We studied participants in the Framingham Study with new‐onset AF or CHF. Multivariable Cox proportional hazards models with time‐dependent variables were used to evaluate whether mortality after AF or CHF was affected by the occurrence and timing of the other condition. Hazard ratios (HRs) were adjusted for time period and cardiovascular risk factors. During the study period, 1470 participants developed AF, CHF, or both. Among 382 individuals with both conditions, 38% had AF first, 41% had CHF first, and 21% had both diagnosed on the same day. The incidence of CHF among AF subjects was 33 per 1000 person‐years, and the incidence of AF among CHF subjects was 54 per 1000 person‐years. In AF subjects, the subsequent development of CHF was associated with increased mortality (men: HR 2.7; 95% CI, 1.9 to 3.7; women: HR 3.1; 95% CI, 2.2 to 4.2). Similarly, in CHF subjects, later development of AF was associated with increased mortality (men: HR 1.6; 95% CI, 1.2 to 2.1; women: HR 2.7, 95% CI, 2.0 to 3.6). Preexisting CHF adversely affected survival in individuals with AF, but preexisting AF was not associated with adverse survival in those with CHF. Conclusions Individuals with AF or CHF who subsequently develop the other condition have a poor prognosis. Additional studies addressing the pathogenesis, prevention, and optimal management of the joint occurrence of AF and CHF appear warranted. (Circulation. 2003;107:2920‐2925.)

The effects of specific medical conditions on the functional limitations of elders in the Framingham Study.

OBJECTIVES The purpose of this study was to identify associations between specific medical conditions in the elderly and limitations in functional tasks; to compare risks of disability across medical conditions, controlling for age, sex, and comorbidity; and to determine the proportion of disability attributable to each condition. METHODS The subjects were 709 noninstitutionalized men and 1060 women of the Framingham Study cohort (mean age 73.7 +/- 6.3 years). Ten medical conditions were identified for study: knee osteoarthritis, hip fracture, diabetes, stroke, heart disease, intermittent claudication, congestive heart failure, chronic obstructive pulmonary disease, depressive symptomatology, and cognitive impairment. Adjusted odds ratios were calculated for dependence on human assistance in seven functional activities. RESULTS Stroke was significantly associated with functional limitations in all seven tasks; depressive symptomatology and hip fracture were associated with limitations in five tasks; and knee osteoarthritis, heart disease, congestive heart failure, and chronic obstructive pulmonary disease, were associated with limitations in four tasks each. CONCLUSIONS In general, stroke, depressive symptomatology, hip fracture, knee osteoarthritis, and heart disease account for more physical disability in noninstitutionalized elderly men and women than other diseases.

Epidemiologic assessment of chronic atrial fibrillation and risk of stroke The fiamingham Study

Chronic atrial fibrillation (AF) as a precursor of stroke was assessed over 24 years of follow-up of the general population sample at Framingham, Massachusetts. Persons with chronic established AF, with or without rheumatic heart disease (RHD), are at greatly increased risk of stroke, and the stroke is probably due to embolism. Chronic AF in the absence of RHD is associated with more than a fivefold increase in stroke incidence, while AF with RHD has a 17-fold increase. Stroke occurrence increased as duration of AF increased, with no evidence of a particularly vulnerable period. Chronic idiopathic AF is an important precursor of cerebral embolism. Controlled trials of anticoagulants or antiarrhythmic agents in persons with chronic AF may demonstrate if strokes can be prevented in this highly susceptible group.

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.