Newly diagnosed atrial fibrillation is an independent factor for future major adverse cardiovascular events

Objectives: This study aims to investigate the impact of newly diagnosed atrial fibrillation (AF) on future major adverse cardiac events (MACE). AF is the most common form of cardiac arrhythmia and is associated with several other cardiovascular (CV) events. Little is known about whether newly diagnosed AF is an independent factor for future MACE, especially in patients without such a history. Methods and Results: We evaluated data from the National Health Insurance Research Database, which represented a retrospective cohort of 713,288 adults in Taiwan from 2006 to 2010. Individuals with previous MACE were excluded. Newly diagnosed AF patients were identified by assigning International Classification of Diseases codes. Propensity score matching adjusted for gender, age, hypertension, diabetes mellitus and dyslipidemia. Cox proportional hazard models estimated future MACE ratios. We compared a total of 3,737 patients with newly diagnosed AF and 704,225 patients without. After matching, there was no difference in baseline demographic characteristics in patients across newly diagnosed AF and non-AF groups. The result showed that newly diagnosed AF in multivariate analysis were associated with increased incidents of MACE (hazard ratio: 3.11-3.51 in different models) and mortality. Newly diagnosed AF without other CV risk factors had 8.45 times the risk of developing future MACE than healthy adults. The more associated CV risk factors in addition to AF, the increased rate of future CV events.