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Articles by R. S. Vasan
Total Records ( 5 ) for R. S. Vasan
  M. J Pencina , R. B D'Agostino , M. G Larson , J. M Massaro and R. S. Vasan
 

Background— Present cardiovascular disease (CVD) risk prediction algorithms were developed for a ≤10-year follow up period. Clustering of risk factors at younger ages and increasing life expectancy suggest the need for longer-term risk prediction tools.

Methods and Results— We prospectively followed 4506 participants (2333 women) of the Framingham Offspring cohort aged 20 to 59 years and free of CVD and cancer at baseline examination in 1971–1974 for the development of "hard" CVD events (coronary death, myocardial infarction, stroke). We used a modified Cox model that allows adjustment for competing risk of noncardiovascular death to construct a prediction algorithm for 30-year risk of hard CVD. Cross-validated survival C statistic and calibration 2 were used to assess model performance. The 30-year hard CVD event rates adjusted for the competing risk of death were 7.6% for women and 18.3% for men. Standard risk factors (male sex, systolic blood pressure, antihypertensive treatment, total and high-density lipoprotein cholesterol, smoking, and diabetes mellitus), measured at baseline, were significantly related to the incidence of hard CVD and remained significant when updated regularly on follow-up. Body mass index was associated positively with 30-year risk of hard CVD only in models that did not update risk factors. Model performance was excellent as indicated by cross-validated discrimination C=0.803 and calibration 2=4.25 (P=0.894). In contrast, 30-year risk predictions based on different applications of 10-year functions proved inadequate.

Conclusions— Standard risk factors remain strong predictors of hard CVD over extended follow-up. Thirty-year risk prediction functions offer additional risk burden information that complements that of 10-year functions.

  W Lieb , V Xanthakis , L. M Sullivan , J Aragam , M. J Pencina , M. G Larson , E. J Benjamin and R. S. Vasan
 

Background— Information is limited on the longitudinal tracking of left ventricular (LV) mass over the adult life course and the determinants of such change.

Methods and Results— We used multilevel modeling to evaluate the correlates of LV mass prospectively over a 16-year period in 4217 Framingham study participants (mean age 45 years, 53% women) using up to 4 serial routine echocardiographic observations on each individual (11 762 observations). Age, sex, body mass index, systolic blood pressure, antihypertensive treatment, smoking, and diabetes mellitus were related to longitudinal measures of LV mass. Women and participants with diabetes mellitus experienced a steeper increase in LV mass with advancing age (compared with men and those without diabetes mellitus; P for interactions <0.0001 and 0.0003, respectively). Women also displayed greater increments in LV mass with increasing body mass index (compared with men, P=0.04 for interaction). Participants with optimal values of these risk factors experienced lesser increases in LV mass over time. Analyses evaluating short-term (4-year) changes in LV mass (2605 unique individuals providing 4494 observations) identified the same key determinants that influenced its long-term trajectory (ie, body mass index, sex, systolic blood pressure, antihypertensive treatment, and smoking).

Conclusions— Our longitudinal observations on a large community-based sample identified higher blood pressure, excess adiposity, smoking, and diabetes mellitus as fundamental determinants of LV mass tracking over the adult life course. These observations are consistent with the notion that maintenance of optimal levels of these risk factors in midlife will reduce the burden of LV hypertrophy, and possibly heart failure, in older age.

  N. L Smith , J. F Felix , A. C Morrison , S Demissie , N. L Glazer , L. R Loehr , L. A Cupples , A Dehghan , T Lumley , W. D Rosamond , W Lieb , F Rivadeneira , J. C Bis , A. R Folsom , E Benjamin , Y. S Aulchenko , T Haritunians , D Couper , J Murabito , Y. A Wang , B. H Stricker , J. S Gottdiener , P. P Chang , T. J Wang , K. M Rice , A Hofman , S. R Heckbert , E. R Fox , C. J O'Donnell , A. G Uitterlinden , J. I Rotter , J. T Willerson , D Levy , C. M van Duijn , B. M Psaty , J. C. M Witteman , E Boerwinkle and R. S. Vasan
  Background—

Although genetic factors contribute to the onset of heart failure (HF), no large-scale genome-wide investigation of HF risk has been published to date. We have investigated the association of 2 478 304 single-nucleotide polymorphisms with incident HF by meta-analyzing data from 4 community-based prospective cohorts: the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study.

Methods and Results—

Eligible participants for these analyses were of European or African ancestry and free of clinical HF at baseline. Each study independently conducted genome-wide scans and imputed data to the 2.5 million single-nucleotide polymorphisms in HapMap. Within each study, Cox proportional hazards regression models provided age- and sex-adjusted estimates of the association between each variant and time to incident HF. Fixed-effect meta-analyses combined results for each single-nucleotide polymorphism from the 4 cohorts to produce an overall association estimate and P value. A genome-wide significance P value threshold was set a priori at 5.0x10–7. During a mean follow-up of 11.5 years, 2526 incident HF events (12%) occurred in 20 926 European-ancestry participants. The meta-analysis identified a genome-wide significant locus at chromosomal position 15q22 (1.4x10–8), which was 58.8 kb from USP3. Among 2895 African-ancestry participants, 466 incident HF events (16%) occurred during a mean follow-up of 13.7 years. One genome-wide significant locus was identified at 12q14 (6.7x10–8), which was 6.3 kb from LRIG3.

Conclusions—

We identified 2 loci that were associated with incident HF and exceeded genome-wide significance. The findings merit replication in other community-based settings of incident HF.

  W Lieb , J. P Zachariah , V Xanthakis , R Safa , M. H Chen , L. M Sullivan , M. G Larson , H. M Smith , Q Yang , G. F Mitchell , J. A Vita , D. B Sawyer and R. S. Vasan
  Background—

Experimental studies suggest that endothelial growth factors play an important role in angiogenesis and vascular remodeling. The clinical and genetic correlates of circulating angiopoietin-2 (Ang-2) and its soluble receptor/regulator Tie-2 (sTie-2) have not been determined in a community-based sample.

Methods and Results—

Serum Ang-2 and sTie-2 were assayed in 3778 third-generation cohort participants of the Framingham Heart Study (mean age, 40±9 years; 53% women). Clinical correlates and heritability of both biomarkers were assessed using generalized estimating equations and variance-component analyses. Ang-2 levels were higher and sTie-2 levels were lower in women than in men. Ang-2 was positively related to age, smoking, systolic blood pressure, hypertension treatment, and diabetes (P<0.05 for all) but was inversely associated with total cholesterol and diastolic blood pressure (P<0.0001 for both), and sTie-2 was positively associated with body mass index, diabetes, and triglycerides but was inversely related to age, alcohol consumption, and glomerular filtration rate (P<0.05 for all). Both Ang-2 and sTie-2 were higher in participants with metabolic syndrome (P<0.005), with stronger associations of Ang-2 with blood pressure traits and of sTie-2 with obesity-dyslipidemia components. Heritability estimates for Ang-2 and sTie-2 were 27% and 56%, respectively (P<0.0001). A region on chromosome 9 was significantly linked to circulating sTie-2 levels (logarithm of the odds score, 8.31).

Conclusion—

Circulating levels of Ang-2 and sTie-2 are heritable traits associated with cardiovascular disease risk factors, including the metabolic syndrome. These observations are consistent with the notion that angiogenesis and vascular remodeling are determined in part by genetic influences and associated with metabolic risk factors.

  E Schwedhelm , V Xanthakis , R Maas , L. M Sullivan , F Schulze , U Riederer , R. A Benndorf , R. H Boger and R. S. Vasan
 

Background: Accumulating evidence links higher circulating asymmetric dimethylarginine (ADMA) to greater risk of cardiovascular disease (CVD). Relatively small differences in ADMA concentrations between healthy individuals and those with disease underscore the need to formulate reference intervals that may aid risk stratification of individuals.

Methods: We formulated reference intervals for plasma ADMA concentrations using a community-based reference sample from the Framingham Offspring Study consisting of 1126 nonsmoking individuals [mean (SD) age 56 (9) years; 60% women] who were free of clinical CVD, hypertension, diabetes, and obesity and who attended a routine examination at which ADMA was assayed. ADMA concentrations were determined using a validated tandem mass spectrometry–liquid chromatography assay.

Results: In the study sample, the mean ADMA concentration was 0.52 (0.11) µmol/L, and the reference limits were 0.311 and 0.732 (2.5th and 97.5th percentile). The sex-specific reference limits were 0.310 and 0.745 in men and 0.313 and 0.721 µmol/L in women. In multivariable regression analysis, ADMA plasma concentrations were positively correlated with age and total plasma homocysteine (both P < 0.001).

Conclusions: Reference limits calculated for circulating ADMA in our large community-based healthy reference sample confirm the previous observation of a relatively narrow distribution of concentrations. This suggests a tight physiological control of ADMA plasma concentrations, presumably by dimethylarginine dimethylaminohydrolase (DDAH) metabolism of ADMA.

 
 
 
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