Different types of atrial fibrillation, renal function, and mortality in elderly Chinese patients with coronary artery disease

Background: Atrial fibrillation (AF) is the most common arrhythmia in patients with chronic kidney disease (CKD), and the combined prevalence of these two disorders increases as the population ages. Both AF and CKD have risk factors for development of each other and eventual mortality. However, the relationship between different types of AF, CKD, and mortality remains unclear, especially in elderly Chinese patients with coronary artery disease. Methods: This study comprised 1,050 patients of median age 86 (60-104) years with coronary artery disease. The end point was all-cause death during a mean follow-up of 417 days. Results: Of 219 patients identified to have AF, 128 had paroxysmal type, 44 had persistent type, and 47 had permanent type. After adjusting for confounders, the estimated glomerular filtration rate was lower and the prevalence of CKD was higher in patients with permanent AF but not in those with paroxysmal or persistent AF. During follow-up, 106 non-CKD patients and 112 CKD patients died; mortality was significantly higher in CKD patients with AF than in those without AF (36 [40.9%] versus 76 [26.8%]), but not in patients without CKD (17 [13.0%] versus 89 [16.3%]). In patients with CKD, paroxysmal AF was independently associated with higher mortality after adjustment but not persistent or permanent AF. No type of AF had an independent association with mortality in patients without CKD. Conclusion: All types of AF had a high prevalence. Permanent AF was independently associated with an increased prevalence of CKD and a decreased estimated glomerular filtration rate. Paroxysmal AF was an independent risk factor for survival in patients with CKD but not in those without CKD.