Atrial Fibrillation - Abstract Poster Session

Nearly a dozen posters were presented during this final-day poster session, featuring results of studies looking at such topics as postmenopausal hormone therapy, pericardial fat, birth weight in women, chronic kidney disease, metabolic syndrome, pulmonary toxicity associated with amiodarone, and risk stratification schemes. The results of these studies are highlighted.

Effects of Postmenopausal Hormone Therapy on Atrial Fibrillation Marco Perez, Paul J. Wang, and Marcia Stefanick, Stanford University, Stanford, CA; Barbara Cochrane, University of Washington, Seattle, WA; J. David Curb, University of Hawaii, Honolulu, HI; Liviu Klein, Northwestern University, Chicago, IL; Joseph Larson, Women's Health Initiative, Seattle, WA; JoAnn Manson, Harvard Medical School, Boston, MA; Lisa W. Martin, George Washington University, Washington, DC; Jennifer Robinson, University of Iowa, Iowa City, IA; and Sylvia Wassertheil-Smoller, Albert Einstein College of Medicine, Bronx, NY According to Perez, this research was conducted because the "effects of postmenopausal hormone therapy (PHT) on atrial fibrillation have not been well characterized," despite knowledge that rates of AF differ between women and men. Results of the study show that between PHT and placebo use, no statistically significant differences exist in overall risk of developing AF. However, in certain subgroups who were at a higher baseline risk for AF, augmentation is risk for AF may be seen with estrogen use.

Pericardial Fat Is Associated with Prevalent AF - The Framingham Heart Study George Thanassoulis, Christopher J. O'Donnell, Daniel Levy, Ramachandran S. Vasan, Caroline S. Fox, and Emilia J. Benjamin, NIH/NHLBI Framingham Heart Study, Framingham, MA; Joseph M. Massaro, Boston University School of Public Health, Boston, MA; Udo Hoffman, Patrick T. Ellinor, and Thomas J. Wang, Massachusetts General Hospital, Boston, MA

Thanassoulis and colleagues "sought to evaluate the association between pericardial fat and prevalent AF," as it was believe that pericardial fat might locally influence AF risk. Even after adjusting for established AF risk factors and BMI, the investigators found that pericardial fat is associated with prevalent AF, whereas intrathoracic and visceral abdominal fat are not.

Association of Chronic Kidney Disease with Atrial Fibrillation in the United States Usman Baber and Jonathan L. Halperin, Mount Sinai School of Medicine, New York, NY; Virginia Howard, Xiao Zhang, David G. Warnock, and Paul Muntner, University of Alabama at Birmingham, Birmingham, AL; Elsayed Z. Soliman, Wake Forest University School of Medicine, Winston-Salem, NC; William M. McClellean, Emory University School of Medicine, Atlanta, GA Baber explained that this study sought to determine the association between chronic kidney disease (CKD) and ECG-confirmed AF in 26,917 participants of the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, "a population-based cohort of African-American and white US adults 45 years of age." Their results confirmed the association of CKD with increased AF prevalence in the study population.

Independent Clinical Correlates of Atrial Fibrillation in Postmenopausal Women: The Women's Health Initiative Observational Study Marco Perez, Paul J. Wang, and Marcia L. Stefanick, Stanford University Hospital, Stanford, CA; Liviu Klein, Northwestern University, Chicago, IL; Stephanie Connelly, University of Tennessee Health Science Center, Memphis, TN; Joseph Larson, Women's Health Initiative, Washington, DC; Marian Limacher, University of Florida, Gainesville, FL; JoAnn Manson, Harvard Medical School, Boston, MA; Lisa W. Martin, George Washington University, Washington, DC; Ronald Prineas and Elsayed Soliman, Wake Forest University School of Medicine, Winston-Salem, NC; Beatriz L. Rodriguez, University of Hawaii, Honolulu, HI; Sylvia Smoller, Albert Einstein College of Medicine, Bronx, NY Perez also presented this poster, focused on a study that was conducted because reasons behind by women are at a lower risk than men of developing AF are not well known, with "large studies of risk factors for developing AF" lacking. The research team discovered that differential "exposures to endogenous and therapeutic hormones may be modestly associated with atrial fibrillation independent of other cardiovascular risk factors," and that coronary and peripheral vascular diseases "are associated with an increased prevalence of AF in women."

Birth Weight Is a Significant Risk Factor for the Development of Atrial Fibrillation in Women David Conen, University Hospital Basel, Basel, Switzerland; Usha B. Tedrow, Julie E. Buring, and Christine M. Albert, Brigham & Women's Hospital, Boston, MA Although the connections between low birth weight and increased risk of coronary artery disease, type 2 diabetes, and hypertension during adulthood are well known, explained Conen, little was know prior to this study regarding the association between incident AF and birth weight. After following 27,980 women from 1993 to 2008, Conen and colleagues learned that birth weight "is a strong and independent predictor of incident AF, indicating that early life determinants may play an important role in the pathogenesis of AF."

Individual and Joint Effects of Metabolic Syndrome Components and Risk of Incident Atrial Fibrillation in Women Brendan M. Everett, Paul M. Ridker, Julie E. Buring, and Christine M. Albert, Brigham & Women's Hospital, Boston, MA; David Conen, University Hospital Basel, Basel, Switzerland Because the strength of the association between metabolic syndrome and AF is less-well described than the relationship between the latter and elevated blood pressure and obesity, Everett, et al. completed this research that followed 23,561 otherwise healthy women to prospectively look for AF occurrence. They found, in fact, that the only components or metabolic syndrome that are associated with risk of AF are obesity and blood pressure.

Atrial Fibrillation and Warfarin: Time in Therapeutic Range - An Electronic Medical Record System Study of Real-world Practice Marc Rosenman and William Tierney, Regenstrief Institute and Indiana University School of Medicine; Teresa Simon and Joseph Jackson, Bristol-Myers Squibb Co, Lawrenceville, NJ; Evgenia Teal and Patricia McGuire, Regenstrief Institute, Indianapolis, IN According to Rosenman, this research was carried out because the research team felt a "study of longitudinal INR levels among a cohort of patients with atrial fibrillation and/or flutter (AF) could enhance understanding of time-in-therapeutic-range and the effectiveness and risks of warfarin." What they found was that patients with AF often were not in the therapeutic range, with stroke and GI bleeding rates the lowest in that range. Rosenman explained that these results "help depict the relationship between two clinical outcomes and warfarin/INR 'in range' exposure."

Pulmonary Toxicity Associate with Amiodarone: Population-level Incidence and Risk Factors Cynthia Jackevicius, Albert Tom, Western University, Pomona, CA; Vidal Essebag, Mark Eisenberg, Elham Rahme, Hassan Behlouli, Hugues Richard, and Louise Pilote, McGill University, Montreal, Quebec, Canada; Jack Tu, Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Karin Humphries, Provincial Health Services Authority, Vancouver, British Columbia, Canada This "retrospective retrospective cohort study using linked administrative databases containing hospital discharge abstracts, prescription claims and vital status from Quebec, Canada between 1999 -2007" reports "the first population-based incidence and potential predictors of AAPT in a real-world setting," said Jackevicius. The results show that population-based incidence of amiodarone-associated pulmonary toxicity "is in the lower range of what has been previously reported. However, amiodarone users with AF have an approximately 2-fold higher risk of PT than non-users. A greater risk of PT was associated with higher dose, male sex, and comorbidities primarily linked to amiodarone metabolism."

Atrial Fibrillation Patients Predominantly Present Ischemic Stroke with Seasonal Incidence Variation Compared to Non-atrial Fibrillation Patients: A Populaiton-based Cohort Study in Taiwan Po-Yen Ko, Kuan-Cheng Chang, Chiung-Ray Lu, Chen-Chia Yang, and Yuan-Teh Lee, China Medical University Hospital, Taichung, Taiwan; Fung-Chang Sung, China Medical University, Taichung, Taiwan Chang explained that the above investigators looked at the "incidence of first stroke, the stroke subtype and seasonal variations among AF patients who underwent optimal medical care." They found that despite increasing use of both anti-platelet and anti-thrombotic therapy in Taiwan, stroke-induced AF "remains a major healthcare challenge," with most AF-related strokes of the non-hemorrhagic type.

Comparison of Risk Stratification Schemes for Stroke in Atrial Fibrillation Tjeerd P. van Staa, Bill Zhang, and Efrosini Setakis, General Practice Research Database, London, UK; Deidre Lane and Gregory Y. Lip, University Department of Medicine, University of Birmingham, Birmingham, UK The objective of this study, explained Lip, "was to compare the predictive ability of published stratification schemes for stroke risk in actual clinical practice in the UK," with 15 schemes identified, including "CHADS₂, Framingham, NICE, AFI, SPAF and ACC/AHA/ESC 2006." Using the majority of these published schemes can help predict stroke in patients with AF modestly well, the researchers concluded. Lip noted, however, that the development of "a better risk stratification schema is warranted."