Gender differences, outcomes and trends among nonagenarian with atrial fibrillation: insight from National Inpatient Sample database

BACKGROUND: Nonagenarians (NG), individuals aged ≥ 90 years, constitute an increasing proportion of hospitalizations presenting with atrial fibrillation (AF). However, not much is known about demographics, clinical outcomes, and trends of hospitalizations. Therefore, we analyzed data about hospitalizations and clinical outcomes among NGs with AF over ten years from 2005 to 2014 using a publically available database, the National Inpatient Sample. METHODS: All hospitalizations and major outcomes of subjects ≥ 90 years with a primary diagnosis of AF (ICD-9-CM code 427.31) over a ten-year period were assessed in this study by multivariate logistic regression analysis. RESULTS: There were more females than males (176,268 females, 51,384 males) in this analysis. The number of hospitalizations for AF among NG increased by 50% (17,295 in 2005 to 25,830 in 2014). Males were more likely to undergo cardioversion (6.14% of males vs. 5.06% of females, P < 0.0001). Over this period, in-hospital mortality declined from 3.21% in 2005 to 2.38% in 2014 ( P = 0.0041), with higher in-hospital mortality in males (3.23% in males vs. 2.76% in females, P = 0.0138), mean length of hospitalization decreased from 4.53 days to 4.13 days (P < 0.0001), the prevalence of congestive heart failure fell from 0.48% to 0.23% ( P = 0.0257), and the use of anticoagulation increased from 6.09% to 14.54% (P < 0.0001). In a multivariate analysis, hospital admission on the weekend, Elixhauser comorbidity index, CHA (2)DS(2)VASc score, acute respiratory failure, and the length of hospital stay were associated with a higher risk of in-hospital mortality. CONCLUSIONS: From 2005 to 2014, AF-related hospitalizations among NGs increased, more so in in females population, mortality trends improved, rates of anticoagulation increased, and cardioversions increased. Despite the decreasing trend of in-hospital mortality since 2005, the relatively high mortality rate in males warrants further studies.