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Biomedical subjects

Joseph M Massaro

Publications and source records attributed to Joseph M Massaro.

At least 19 recordsLinked to original sources

Evidence for lower variability of coronary artery calcium mineral mass measurements by multi-detector computed tomography in a community-based cohort--consequences for progression studies.

PURPOSE: To compare the measurement variability for coronary artery calcium (CAC) measurements using mineral mass compared with a modified Agatston score (AS) or volume score (VS) with multi-detector CT (MDCT) scanning, and to estimate the potential impact of these methods on the design of CAC progression studies. MATERIALS AND METHODS: We studied 162 consecutive subjects (83 women, 79 men, mean age 51 +/- 11 years) from a general Caucasian community-based cohort (Framingham Heart Study) with duplicate runs of prospective electrocardiographically-triggered MDCT scanning. Each scan was independently evaluated for the presence of CAC by four experienced observers who determined a "modified" AS, VS and mineral mass. RESULTS: Of the 162 subjects, CAC was detected in both scans in 69 (42%) and no CAC was detected in either scan in 72 (45%). Calcium scores were low in the 21/162 subjects (12%) for whom CAC was present in one but not the other scan (modified AS < 20 in 20/21 subjects, mean AS 4.6 +/- 1.9). For all three quantification algorithms, the inter- and intraobserver correlation were excellent (r > 0.96). However, the mean interscan variability was significantly different between mineral mass, modified AS, and VS (coefficient of variation 26 +/- 19%, 41 +/- 28% and 34 +/- 25%, respectively; p < 0.04), with significantly smaller mean differences in pair-wise comparisons for mineral mass compared with modified AS (p < 0.002) or with VS (p < 0.03). The amount of CAC but not heart rate was an independent predictor of interscan variability (r = -0.638, -0.614 and -0.577 for AS, VS, and mineral mass, respectively; all p < 0.0001). The decreased interscan variability of mineral mass would allow a sample size reduction of 5.5% compared with modified AS for observational studies of CAC progression and for randomized clinical trials. CONCLUSION: There is significantly reduced interscan variability of CAC measurements with mineral mass compared with the modified AS or VS. However, the measurement variability of all quantification methods is predicted by the amount of CAC and is inversely correlated to the extent of partial volume artifacts. Moreover, the improvement of measurement reproducibility leads to a modest reduction in sample size for observational epidemiological studies or randomized clinical trials to assess the progression of CAC.

Adult↗

Association of white matter hyperintensity volume with decreased cognitive functioning: the Framingham Heart Study.

OBJECTIVE: To examine the relationship between white matter hyperintensity (WMH) volume on magnetic resonance images and cognitive tests in a large, population-based sample. METHODS: Quantitative magnetic resonance imaging and neuropsychological evaluations were performed in 1820 dementia- and stroke-free participants from the Framingham Offspring Cohort. The WMH volume relative to total cranial volume was computed; WMH volumes more than 1 SD above the age-predicted mean were defined as large. Adjusting for age, sex, education, height, and Framingham Stroke Risk Profile, we examined the relationship between WMH and 3 cognitive factors derived from a neuropsychological test battery (verbal memory, visuospatial memory and organization, and visual scanning and motor speed) and 3 individual measures of new learning, abstract reasoning, and naming. RESULTS: Compared with those with no or little WMH volume, participants with large WMH volume performed worse on the cognitive factors of visuospatial memory and organization (P = .04) and visual scanning and motor speed (P = .01), as well as on new learning (P = .04), but not on verbal memory (P = .52). CONCLUSIONS: In this younger community-based population of nondemented individuals, those with large WMH volume, as compared with those with less or no WMH volumes, performed significantly worse in cognitive domains generally associated with frontal lobe systems and, to a lesser extent, the medial temporal area. Further study will clarify whether large WMH volume and associated cognitive impairment lead to future risk of stroke or dementia.

Age Factors↗

Genome-wide scan for white matter hyperintensity: the Framingham Heart Study.

BACKGROUND AND PURPOSE: White matter hyperintensity (WMH) volume is associated with aging and cerebrovascular disease and has been demonstrated to have a high heritability in the Framingham Heart Study as well as in other studies. We performed a genome-wide linkage analysis to identify chromosomal regions that may harbor genes influencing WMH in a family-based sample of the Framingham Heart Study. METHODS: Brain magnetic resonance scans were performed, and WMH and total cranial volume (TCV) were quantified as previously described on 2259 cohort and offspring participants. The outcome used for linkage analysis was an age specific (within 10-year age groups) z-score for the natural logarithm of the ratio of WMH to TCV. This z-score was based on 2230 individuals after excluding 26 participants with neurological conditions other than stroke and 3 individuals whose ages were out of range. Variance component linkage analysis included 747 individuals (mean age=62.16+/-12.43 years) with both magnetic resonance measure and genotype information in 237 families. Mean percent WMH to TCV was 0.098+/-0.175 with a range of 0.00025% to 1.37% in the linkage analysis subjects. RESULTS: A maximum multipoint logarithm of the odds (LOD) score=3.69, which indicates significant evidence of linkage, was observed at 4 cM on chromosome 4. A suggestive peak with LOD=1.78 was observed at 95 cM on chromosome 17. CONCLUSIONS: We have significant evidence that a gene influencing WMH volume is located on chromosome 4 of the human genome.

Adult↗

CCL2 polymorphisms are associated with serum monocyte chemoattractant protein-1 levels and myocardial infarction in the Framingham Heart Study.

BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) is a chemokine strongly implicated in promoting atherosclerosis in animal models, but human genetic evidence is contradictory. METHODS AND RESULTS: We analyzed the association of genetic variation in the MCP-1 gene (CCL2) with prevalent myocardial infarction and serum MCP-1 levels in the community-based Framingham Heart Study Offspring Cohort (50% women; mean age, 62 years). MCP-1 levels and CCL2 genotypes were determined in 3236 and 1797 individuals, respectively. Significant clinical correlates of MCP-1 levels were age, cigarette smoking, triglycerides, body mass index, and waist-to-hip ratio. The MCP-1-2578G allele located in the CCL2 regulatory region was significantly associated with both higher serum MCP-1 levels in a recessive genetic model (358+/-10 versus 328+/-3 pg/mL; P=0.002) and higher prevalence of myocardial infarction in a dominant genetic model (adjusted odds ratio, 2.0; 95% CI, 1.2 to 3.3; P=0.005). We also defined the linkage disequilibrium structure at the CCL2 locus and observed 6 common haplotypes in whites. We performed haplotype-based association analysis and found that only the most frequent haplotype, defined by the MCP-1-2578G allele, was associated with prevalent MI. CONCLUSIONS: Our data are consistent with the hypothesis that MCP-1 is involved in the pathogenesis of human atherosclerosis and myocardial infarction.

Aged↗

Genome scan of systemic biomarkers of vascular inflammation in the Framingham Heart Study: evidence for susceptibility loci on 1q.

Vascular inflammation plays a central role in atherosclerosis and inflammatory biomarkers predict risk of cardiovascular disease (CVD). Thus, finding genes that influence systemic levels of inflammatory biomarkers may provide insights into genetic determinants of vascular inflammation and CVD. We conducted variance-component linkage analyses of blood levels of four biomarkers of vascular inflammation [C-reactive protein (CRP), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), soluble intercellular adhesion molecule-1 (sICAM-1)] in 304 extended families from the Framingham Heart Study, using data from a 10cM genome scan. We computed p-values by a permutation approach. Heritability estimates ranged from 14% (IL-6) to 44% (MCP-1) after log transforming and adjusting for covariates. Significant linkage to MCP-1 was found on chromosome 1 (LOD=4.27 at 186cM; genome-wide p=0.005), in a region containing inflammatory candidate genes such as SELE, SELP (E- and P-selectin) and CRP. Other linkage peaks with LOD scores >2 were found for MCP-1 on chromosome 1 (LOD=2.04 at 16cM; LOD=2.34 at 70cM) and chromosome 17 (LOD=2.44 at 22cM) and for sICAM-1 on chromosome 1 at 229cM (LOD=2.09) less than 5cM from the interleukin-10 (IL10) gene. Multiple genes on chromosome 1 may influence inflammatory biomarker levels and may have a potential role in development of CVD.

Aged↗

Alcohol consumption and platelet activation and aggregation among women and men: the Framingham Offspring Study.

BACKGROUND: Alcohol intake has been associated with lower platelet activity; however, few large-scale studies have included women, and to our knowledge, the relationship of alcohol intake with measures of platelet activation has not been studied. METHODS: We performed a cross-sectional analysis of adults free of cardiovascular disease enrolled in the Framingham Offspring Study. Study physicians assessed alcohol consumption with a standardized questionnaire. We measured platelet activation in response to 1 and 5 microm of adenosine diphosphate (ADP) with a P-selectin assay among 1037 participants and platelet aggregability in response to ADP, epinephrine, and collagen among 2013 participants. RESULTS: Alcohol consumption was inversely associated with P-selectin expression in response to 1 microm ADP (p = 0.007) and 5 microm ADP (p = 0.02) among men but not women. Alcohol consumption was also inversely associated with platelet aggregation induced by ADP among both women (p = 0.04) and men (p trend = 0.008) and by epinephrine among men (p = 0.03) CONCLUSIONS: Alcohol consumption is inversely associated with both platelet activation and aggregation, particularly in men. Additional research is needed to determine whether these findings contribute to the contrasting associations of alcohol consumption with risk of thrombotic and hemorrhagic cardiovascular events.

Adenosine Diphosphate↗

Brachial artery vasodilator function and systemic inflammation in the Framingham Offspring Study.

BACKGROUND: In experimental studies, traditional risk factors and proinflammatory processes alter the regulatory functions of the vascular endothelium to promote atherosclerosis. These alterations include expression of leukocyte adhesion molecules and decreased bioavailability of endothelium-derived nitric oxide, an important regulator of vascular homeostasis and tone. The precise relations among risk factors, inflammation, and nitric oxide bioavailability remain uncertain. METHODS AND RESULTS: To test the hypothesis that inflammation impairs endothelial function in humans, we measured brachial artery flow-mediated dilation, reactive hyperemia, and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intracellular adhesion molecule-1 (sICAM-1), and monocyte chemotactic protein-1 (MCP-1) in 2701 participants from the Framingham Study (mean age 61 years, 53% women). There were modest unadjusted inverse correlations between flow-mediated dilation and CRP, IL-6, and sICAM-1 (P<0.001 for all) that were rendered nonsignificant after accounting for traditional coronary risk factors. For reactive hyperemia, we observed inverse correlations with markers of inflammation in unadjusted models that were attenuated 57% to 74% after accounting for risk factors. However, partial correlations of CRP, IL-6, and sICAM-1 with reactive hyperemia remained significant. CONCLUSIONS: Our observations are consistent with the hypothesis that risk factors induce a state of inflammation that impairs vascular function. For flow-mediated dilation, we found no evidence that inflammation has additional effects beyond those attributable to traditional risk factors. The incremental contribution of CRP, IL-6, and sICAM-1 to reactive hyperemia above and beyond known risk factors suggests that systemic inflammation may contribute to impaired vasomotor function in forearm microvessels.

Biomarkers↗

Utility of the Safe-Cross-guided radiofrequency total occlusion crossing system in chronic coronary total occlusions (results from the Guided Radio Frequency Energy Ablation of Total Occlusions Registry Study).

The Safe-Cross radiofrequency guidewire (IntraLuminal Therapeutics, Carlsbad, California) combines 3 capabilities: (1) steerability of a conventional 0.014-in intermediate-stiffness guidewire, (2) optical coherence reflectometry to warn the operator when the wire tip approaches within 1 mm of the vessel wall, and (3) delivery of radiofrequency energy pulses to the wire tip to facilitate passage through an occluded segment. The Guided Radio Frequency Energy Ablation of Total Occlusions Registry was a prospective, nonrandomized, multicenter registry that enrolled 116 patients who had long-term coronary total occlusions and in whom a >10-minute good-faith attempt to cross the occlusion using conventional guidewires had failed. The median known duration of occlusion was 22 months (32%; >1 year), and the median length of the occluded segment was 25 mm (25%; >30 mm). Device success was achieved in 63 of 116 of patients (54.3%), and major adverse events occurred in 6.9%, consisting predominantly of isolated increases in cardiac enzymes with no procedure-related deaths, Q-wave myocardial infarctions, or emergency bypass operations. Clinical perforation occurred in 2.6% of patients; of these, perforation in only 1 patient (0.9%) was adjudicated to be directly related to the Safe-Cross radiofrequency wire rather than to the stiff and/or hydrophilic wires used after an inability to advance with the Safe-Cross. Based on these data, the device has been approved in Europe and was recently (January 2004) granted 510K clearance by the Food and Drug Administration.

Adult↗

Warfarin and aspirin use and the predictors of major bleeding complications in atrial fibrillation (the Framingham Heart Study).

The Framingham Heart Study records of participants with atrial fibrillation (AF) during 1980 and 1994 were retrospectively reviewed to determine the prevalence of warfarin and aspirin use in AF. Anticoagulant use increased significantly in the 393 men and women (mean ages 72.5 and 79.0 years, respectively) who developed AF over the observation period: aspirin use increased from 14% to 39% in men and from 19% to 33% in women, and warfarin use increased from 10% to 39% in men and from 17% to 38% in women. There were no significant gender differences in anticoagulant use (p = 0.61), but participants using warfarin were younger. A total of 65 participants (17%) had major bleeding complications <or=5 years after initial AF. Age was not a significant predictor of bleeding.

Adult↗

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.

Adult↗

Heritability and correlates of intercellular adhesion molecule-1 in the Framingham Offspring Study.

OBJECTIVES: We sought to determine the clinical factors and heritability associated with inflammation measured as circulating levels of soluble-intercellular adhesion molecule-1 (sICAM-1) in a community-based cohort. BACKGROUND: Several prospective studies indicate that circulating sICAM-1 is predictive of future cardiovascular events. However, in some studies this predictive value is lost after multivariable adjustment for traditional cardiovascular disease (CVD) risk factors. We addressed the heritability of sICAM-1 and its relation to CVD risk factors in a community-based cohort. METHODS: We examined 3,295 subjects from the Framingham Heart Study and measured sICAM-1 levels. We then used linear and stepwise multivariable regression to determine predictors or sICAM-1 levels. RESULTS: In age- and gender-adjusted regression models, increased sICAM-1 levels were positively associated with age, total/high-density lipoprotein cholesterol, systolic blood pressure, body mass index (BMI), blood glucose, diabetes, smoking, and prevalent CVD. In stepwise multivariable regression models, sICAM-1 levels remained associated with age, female gender, total/high-density lipoprotein cholesterol ratio, BMI, blood glucose, smoking, and prevalent CVD. The residual heritability of sICAM-1 was 24%. CONCLUSIONS: In addition to prevalent CVD, established CVD risk factors and non-traditional ones such as BMI were associated with systemic inflammation as determined by sICAM-1 levels. There also is significant heritability of sICAM-1, which suggests a genetic component to systemic inflammation.

Adult↗

Presentation of multivariate data for clinical use: The Framingham Study risk score functions.

The Framingham Heart Study has been a leader in the development and dissemination of multivariable statistical models to estimate the risk of coronary heart disease. These models quantify the impact of measurable and modifiable risk factors on the development of coronary heart disease and can be used to generate estimates of risk of coronary heart disease over a predetermined period, for example the next 10 years. We developed a system, which we call a points system, for making these complex statistical models useful to practitioners. The system is easy to use, it does not require a calculator or computer and it simplifies the estimation of risk based on complex statistical models. This system represents an effort to make available a tool for clinicians to aid in their decision-making process regarding treatment and to assist them in motivating patients toward healthy behaviours. The system is also readily available to patients who can easily estimate their own coronary heart disease risk and monitor this risk over time.

Adult↗

Cerebral microbleeds: prevalence and associations with cardiovascular risk factors in the Framingham Study.

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) are areas of low signal intensity on gradient echo T2*-weighted magnetic resonance imaging (T2*MRI) corresponding to hemosiderin deposits in the perivascular space. Microangiopathy from atherosclerosis or amyloid angiopathy might lead to the formation of these lesions; therefore, there may be associations between CMBs and cardiovascular risk factors, APOE allele status, and brain morphology. We examined these relationships in the Framingham Study (FHS). METHODS: In 472 subjects from the FHS Offspring and Cohort, we related CMB status to age, sex, systolic blood pressure, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels, smoking, diabetes, total hemispheric brain volume, white matter hyperintensity volume (WMHV), and APOE allele status. RESULTS: Overall prevalence of CMBs was 4.7%, but CMBs were more prevalent with advanced age and male sex. Blood pressure, brain volume, and WMHV were related to CMBs in crude analysis but not after adjustment for age and sex. There were no significant relationships demonstrated between CMBs and APOE allele status, cholesterol, smoking, or diabetes. CONCLUSIONS: There is a low prevalence of CMBs in the community and a strong relationship with increasing age and male sex. We found no independent relationships with cardiovascular risk factors, APOE status, brain volumes, or WMH.

Age Factors↗

Genetic variation in white matter hyperintensity volume in the Framingham Study.

BACKGROUND AND PURPOSE: In a previous study of normal elderly male twins, the heritability of quantitative white matter hyperintensity (WMH) volume has been estimated to be high (0.73). We investigated heritability of WMH in a family-based sample of the Framingham Heart Study for sex differences and the impact of age. METHODS: Brain magnetic resonance scans were performed on 2012 individuals in the cohort and offspring of the Framingham study. This report was limited to 1330 stroke-free and dementia-free members (mean age 61.0 years) of the Framingham offspring. Individuals with a history of multiple sclerosis, stroke, dementia, or other neurological condition including traumatic brain injury were excluded from this analysis. WMH volume and total cranial volume (TCV) were quantified using a previously published algorithm. Because of extreme skewing, measures of WMH were log-transformed before analysis. Variance components methods were used to estimate heritability of WMH after adjusting for sex, age, age2, and TCV. RESULTS: In the full dataset, WMH heritability was 0.55 (P<0.0001). Heritability among women was 0.78 (P<0.0001) whereas heritability among men was 0.52 (P<0.0003). Heritability varied as average age increased, with a peak of 0.68 (P<0.0001) in individuals aged 55 or older. CONCLUSIONS: Using a family-based study design comprising generally healthy individuals, this study found high heritability of WMH overall and similar heritability for both men and women. In addition, the heritability of WMH remained high among individuals in whom the prevalence of cerebrovascular brain injury was generally low, suggesting that WMH is also likely to be an excellent genetic marker of brain aging.

Adult↗

Long-term alcohol consumption and the risk of atrial fibrillation in the Framingham Study.

Atrial fibrillation (AF) is a major risk factor for stroke. Although acute alcohol intake has been associated with AF, it is not known whether long-term alcohol consumption in moderation is associated with an increased risk of AF. We used a risk set method to assess the relation of long-term alcohol consumption to the risk of AF among participants in the Framingham Study. For each case, up to 5 controls were selected and matched for age, age at baseline examination, sex, cohort, baseline history of hypertension, congestive heart failure, and myocardial infarction. Within each risk set, alcohol consumption was averaged from baseline until the examination preceding the index case of AF. Of the 1,055 cases of AF occurring during a follow-up of >50 years, 544 were men and 511 were women. In a conditional logistic regression with additional adjustment for systolic blood pressure, age at baseline examination, education, and cumulative history of myocardial infarction, congestive heart failure, diabetes mellitus, left ventricular hypertrophy, and valvular heart disease, the relative risks were 1.0 (reference), 0.97 (95% confidence interval [CI] 0.78 to 1.22), 1.06 (95% CI 0.80 to 1.38), 1.12 (95% CI 0.80 to 1.55), and 1.34 (95% CI 1.01 to 1.78) for alcohol categories of 0, 0.1 to 12, 12.1 to 24, 24.1 to 36, and >36 g/day, respectively. In conclusion, our data indicate little association between long-term moderate alcohol consumption and the risk of AF, but a significantly increased risk of AF among subjects consuming >36 g/day (approximatively >3 drinks/day).

Adult↗

Anticardiolipin antibodies and risk of ischemic stroke and transient ischemic attack: the Framingham cohort and offspring study.

BACKGROUND AND PURPOSE: The role of anticardiolipin antibodies (aCLs) as novel risk factors for ischemic stroke and transient ischemic attacks (TIAs) has been a matter of debate. Prior cohort studies included only selected subjects, mostly men. We related serum concentrations of aCLs to incident first ischemic stroke/TIA among men and women in the Framingham Heart Study cohort and offspring. METHODS: There were a total of 2712 women (mean age, 59.3 years) and 2262 men (mean age, 58.3 years) free of stroke/TIA at the time of their baseline examinations. An enzyme immunoassay was used to measure aCLs. Optical density of the sample serum compared with the reference serum was defined as the aCL screening ratio (aCL SR). Analyses were based on sex-specific aCL SR quartiles and individual ratios. RESULTS: During the 11-year follow-up, 222 ischemic strokes/TIAs occurred. In multivariate analysis, after adjustment for age, prior cardiovascular disease, systolic blood pressure, diabetes, smoking, C-reactive protein, and total and high-density lipoprotein cholesterol levels, an aCL SR of >0.4 (78% of sample) was significantly associated with an increased risk of ischemic stroke/TIA for women (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.3 to 5.4; absolute risk, 3.2%, 95% CI, 2.2 to 4.3) but not in men (HR, 1.3; 95% CI, 0.7 to 2.4; absolute risk, 4.5%; 95% CI, 3.0 to 6.0). Similar results were obtained when the higher 3 aCL SR quartiles were compared with the lowest. CONCLUSIONS: Elevated serum concentrations of aCLs, independently of other cardiovascular risk factors, significantly predict the risk of future ischemic stroke and TIA in women but not in men.

Age Distribution↗

Managing and analysing data from a large-scale study on Framingham Offspring relating brain structure to cognitive function.

At the Framingham Heart Study under separate research grant funding from the National Institute of Aging, NIH, we are gathering brain structure and cognitive information on the Framingham Offspring, creating one of the largest known data sets to assess changes in brain structure associated with normative ageing and cognitive decline. Subject recruitment, data collection, data management and statistical analysis require a collaborative integrated effort on the part of the Framingham project team. Here we describe this effort, as well as the various brain structure and cognitive function parameters we are now collecting. We are currently performing analyses of data collected through 2002, and we discuss the statistical issues arising relating brain structure parameters to cognitive function.

Aged↗

A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: the Framingham Heart Study.

CONTEXT: Prior risk stratification schemes for atrial fibrillation (AF) have been based on randomized trial cohorts or Medicare administrative databases, have included patients with established AF, and have focused on stroke as the principal outcome. OBJECTIVE: To derive risk scores for stroke alone and stroke or death in community-based individuals with new-onset AF. DESIGN, SETTING, AND PARTICIPANTS: Prospective, community-based, observational cohort in Framingham, Mass. We identified 868 participants with new-onset AF, 705 of whom were not treated with warfarin at baseline. Risk scores for stroke (ischemic or hemorrhagic) and stroke or death were developed with censoring when warfarin initiation occurred during follow-up. Event rates were examined in low-risk individuals, as defined by the risk score and 4 previously published risk schemes. MAIN OUTCOME MEASURES: Stroke and the combination of stroke or death. RESULTS: During a mean follow-up of 4.0 years free of warfarin use, stroke alone occurred in 83 participants and stroke or death occurred in 382 participants. A risk score for stroke was derived that included the following risk predictors: advancing age, female sex, increasing systolic blood pressure, prior stroke or transient ischemic attack, and diabetes. With the risk score, 14.3% of the cohort had a predicted 5-year stroke rate < or =7.5% (average annual rate < or =1.5%), and 30.6% of the cohort had a predicted 5-year stroke rate < or =10% (average annual rate < or =2%). Actual stroke rates in these low-risk groups were 1.1 and 1.5 per 100 person-years, respectively. Previous risk schemes classified 6.4% to 17.3% of subjects as low risk, with actual stroke rates of 0.9 to 2.3 per 100 person-years. A risk score for stroke or death is also presented. CONCLUSION: These risk scores can be used to estimate the absolute risk of an adverse event in individuals with AF, which may be helpful in counseling patients and making treatment decisions.

Aged↗