Abstract 16089: Clinical Outcomes Associated With Anti-coagulation versus No Anti-coagulation for Atrial Fibrillation Among Octogenarians and Nonagenarians; a Meta-analysis

Background: Octogenarians and nonagenarians are under-represented in major clinical trials studying the role of anticoagulation (AC) in atrial fibrillation (AF). These patients are at an increased risk of bleeding owing to their frailty, their propensity for falls, and frequently impaired kidney function. We performed a meta-analysis of studies that investigated the role of AC in these patients. Methods: We queried Medline, EmCare, CINHAL, Cochrane Database, and Google Scholar for studies investigating the role of AC for AF in octogenarians and nonagenarians. Our primary efficacy outcome was major thromboembolism (TE), and secondary safety outcome was major bleeding (MB). We used the PM method with HKSJ adjustment to estimate risk ratio (RR) with a 95% confidence interval (CI). Heterogeneity was assessed using Higgin’s I 2 . R version 3.6.2 was used for statistical analysis. Heterogeneity was addressed using outlier analysis. dmetar() package in R was used, and the pooled estimate was re-calculated, excluding the outliers. Results: Ten observational studies, including a total of 34,697 patients were included. There was no difference in the risk of TE [RR: 0.82, 95% CI: 0.49-1.38, I 2 =74%] or MB [RR: 1.00, 95% CI: 0.55-1.83, I 2 =88%] between the AC and Non-AC group. However, the pooled estimates were associated with considerable heterogeneity. Outlier analysis identified two studies "Perera et al., 2009" and "Yamashita et al., 2016" as an outlier for pooled estimation of TE, while [1] "Siu et al., 2014", "Bertozzo et al., 2016", "Ekerstad et al., 2018" and "Alnsasra et al., 2018" were outliers in the pooled estimate of MB. Following exclusion of outliers for each endpoint, the reanalyzed RR for TE and MB were [RR: 0.94, 95% CI: 0.82- 1.09, I 2 =0%] and [RR: 1.57, 95% CI: 1.41- 1.74, I 2 =0%]. Conclusion: There was no difference in the risk of TE, while the risk of MB increased with the use of AC for AF in octogenarians and nonagenarians.