Association Between Atrial Fibrillation and Cognitive Impairment in Individuals With Prior Stroke: A Meta-Analysis and Meta-Regression Analysis.

Background and Purpose- Atrial fibrillation (AF) is the most common chronic arrhythmia. Dementia and cognitive impairment (CI) are major burdens to public health. The prevalence of all 3 entities is projected to increase due to population aging. Previous reports have linked AF with a higher risk of CI and dementia in patients without prior stroke. Stroke is known to increase the risk for dementia and CI. It is unclear if AF in patients with history of stroke can further increase the risk for dementia or CI. Our purpose was to evaluate the impact of AF on risk for dementia or CI among patients with history of stroke. Methods- Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines were followed. Pubmed, Scopus, and Cochrane central were searched. The outcomes of interest were dementia, CI, and the composite end point of dementia or CI. A random-effect model meta-analysis was performed. Meta-regression analysis was also performed. Publication bias was assessed with the Egger test and with funnel plots. Results- Fourteen studies and 14 360 patients (1363 with AF) were included in the meta-analysis. In the meta-analysis of adjusted odds ratio, AF was associated with increased risk of CI (odds ratio, 1.60 [95% CI, 1.20-2.14]), dementia (odds ratio, 3.11 [95% CI, 2.05-4.73]), and the composite end point of CI or dementia (odds ratio, 2.26 [95% CI, 1.61-3.19]). The heterogeneity for the composite end point of dementia or CI was moderate (adjusted analysis). The heterogeneity for the analysis of the end point of CI only was substantial in the unadjusted analysis and moderate in the adjusted analysis. The heterogeneity for the end point of dementia only was moderate in the unadjusted analysis and zero in the adjusted analysis. Conclusions- Our results indicate that an association between AF and CI or dementia is patients with prior strokes is possible given the persistent positive associations we noticed in the unadjusted and adjusted analyses. The heterogeneity levels limit the certainty of our findings.

Hospital and clinical care costs associated with atrial fibrillation for Medicare beneficiaries in the Cardiovascular Health Study and the Framingham Heart Study.

BACKGROUND: Atrial fibrillation is increasingly prevalent as the US population ages and is associated with significant morbidity and mortality. Care for patients with atrial fibrillation can be costly, US health care costs are comparatively high, and there are few cost estimates available that incorporate detailed measurement of comorbidities and their effects on costs. METHODS AND RESULTS: In the Cardiovascular Health Study and the Framingham Heart Study, participants aged 65 years or older with newly diagnosed atrial fibrillation were matched on age and follow-up time to referents free of atrial fibrillation. The total clinical and hospital medical costs paid by Medicare Parts A and B (drug costs from Medicare Part D costs were not included) in the year prior to diagnosis (or matching) were compared with costs in the following year. Estimates were adjusted for other medical conditions and adjusted to 2009 dollars. In the Cardiovascular Health Study, 513 participants were diagnosed with new-onset atrial fibrillation and survived 30 days post-atrial fibrillation diagnosis, and 513 referents (as a control cohort) were identified, with a mean age of 77 years. In the Framingham Heart Study, we identified 336 participants diagnosed with atrial fibrillation, who survived 30 days post-atrial fibrillation diagnosis and matched these participants to 336 referents. We compared these new-onset atrial fibrillation participants with referents, using a difference in difference design to account for both time trends and differences between the two groups. The adjusted incremental cost for participants with atrial fibrillation, compared with referents, was US$18,060 (95% confidence interval: US$14,965-US$21,155) in the Cardiovascular Health Study and US$20,012 (95% confidence interval: US$15,057-US$24,966) in the Framingham Heart Study. The pooled estimate was US$18,601 (95% confidence interval: US$15,981-US$21,234). CONCLUSION: Atrial fibrillation was associated with increased costs in the year after diagnosis in two community-based cohorts, even after careful accounting for age, time period, and systematically measured comorbidities.

Eight genetic loci associated with variation in lipoprotein-associated phospholipase A2 mass and activity and coronary heart disease: meta-analysis of genome-wide association studies from five community-based studies.

AIMS: Lipoprotein-associated phospholipase A2 (Lp-PLA2) generates proinflammatory and proatherogenic compounds in the arterial vascular wall and is a potential therapeutic target in coronary heart disease (CHD). We searched for genetic loci related to Lp-PLA2 mass or activity by a genome-wide association study as part of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. METHODS AND RESULTS: In meta-analyses of findings from five population-based studies, comprising 13 664 subjects, variants at two loci (PLA2G7, CETP) were associated with Lp-PLA2 mass. The strongest signal was at rs1805017 in PLA2G7 [P = 2.4 × 10(-23), log Lp-PLA2 difference per allele (beta): 0.043]. Variants at six loci were associated with Lp-PLA2 activity (PLA2G7, APOC1, CELSR2, LDL, ZNF259, SCARB1), among which the strongest signals were at rs4420638, near the APOE-APOC1-APOC4-APOC2 cluster [P = 4.9 × 10(-30); log Lp-PLA2 difference per allele (beta): -0.054]. There were no significant gene-environment interactions between these eight polymorphisms associated with Lp-PLA2 mass or activity and age, sex, body mass index, or smoking status. Four of the polymorphisms (in APOC1, CELSR2, SCARB1, ZNF259), but not PLA2G7, were significantly associated with CHD in a second study. CONCLUSION: Levels of Lp-PLA2 mass and activity were associated with PLA2G7, the gene coding for this protein. Lipoprotein-associated phospholipase A2 activity was also strongly associated with genetic variants related to low-density lipoprotein cholesterol levels.