[Risk factors of atrial fibrillation in critical ill patients]

To observe the clinical features of atrial fibrillation (AF) patients, and to explore the correlation between the routine detection index and the new-onset AF and to find out risk factors for new AF in critically ill patients.

A prospective observational study was conducted. The patients with AF admitted to intensive care unit (ICU) of the Affiliated Hospital of Guizhou Medical University from March 2016 to June 2017 were enrolled. The patients were divided into new-onset AF group and past-existed AF group according to their past history of AF (including persistent AF, paroxysmal AF or permanent AF). In addition, patients in ICU without history of AF and new-onset AF were selected as the control group (no AF group). The general epidemiological characteristics of patients in three groups, and the blood biochemical, coagulation and other related indicators at the time of AF occurred (new-onset AF group) or 48 hours after ICU admission (AF group and no AF group) were analyzed; the difference of laboratory indexes between patients in new-onset AF group with AF within 48 hours before occurred and patients in no AF group within 48 hours after admission to ICU was compared. The relationship between each index and new-onset AF were analyzed. Pearson or Spearman rank correlation was used for analysis. Risk factors of new-onset AF were analyzed by Logistic regression analysis.

1 673 patients were admitted to ICU, including 179 cases of AF (10.70%), and 106 males and 73 females, with an average age of (71.73±23.22) years. There was 75 new-onset AF (morbidity 4.48%), and had a 28-day mortality of 45.33% (34/75). There were differences in age, previous heart disease and heart failure (HF) among new-onset AF group (n = 75), past-existed AF group (n = 104) and no AF group (n = 75). Compared with other two groups, renal insufficiency rates, troponin, serum sodium, calcium and procalcitonin levels were higher, mechanical ventilation time and the length of ICU stay were significantly prolonged, ICU and hospitalization costs were higher in new-onset AF group. Compared with no AF group, new-onset AF patients with the higher percentage of septic shock, the accumulation of vascular contraction drugs within 24 hours after AF usage were higher, and used more anti-arrhythmic drugs, has higher brain natriuretic peptide (pro-BNP), serum creatinine, blood lactic acid levels, and lower albumin, oxygenation index, and serum potassium levels, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score and 28-day mortality were higher. Correlation analysis showed that age, APACHE II score, septic shock, HF, cardiovascular disease, renal insufficiency were positively correlated with new-onset AF (r values were 0.393, 0.270, 0.386, 0.251, 0.194, 0.170; P values were 0.000, 0.001, 0.000, 0.002, 0.017, 0.037, respectively). The age [odds ratio (OR) = 0.962, P = 0.046], basic oxygenation index (OR = 1.005, P = 0.028) and serum potassium levels (OR = 1.638, P = 0.022) were the risk factors for new-onset AF.

Critical patients with a high incidence of AF, new-onset AF significantly prolong the length of ICU stay; age, APACHE II score, septic shock, cardiovascular disease, and renal insufficiency are related to new-onset AF; age, basic oxygenation index and serum potassium levels are risk factors for new-onset AF.