Introduction: Atrial fibrillation (AF) is the most common arrhythmia in critically ill patients.1 New onset AF (NOAF) is linked with severity of disease and is associated with poorer outcomes, including prolonged ICU stays and higher mortality rates.1–3 In addition, we know that thrombocytopenia is an independent predictor of mortality and that patients with disseminated intravascular coagulation (DIC), who have low platelet counts and coagulopathy, have a high mortality. We suspect that patients with NOAF have a higher risk of manifesting DIC. Whilst national guidelines exist in the UK for management of AF, they are not specific to critical care,4 and the most effective treatment for AF in critical care remains unclear.
Objectives: To retrospectively assess the incidence and outcomes of patients with atrial fibrillation and associated thrombocytopenia and coagulopathy in a cohort of patients admitted to critical care.
Methods: Records of 1,007 patients admitted to critical care at the Royal University Liverpool Hospital between 2008 and 2014 were reviewed. Data was collected where available, including age, gender, APACHE II score, modified ISTH DIC score (using platelet count, prothrombin time and D-dimer), presence of sepsis, presence of AF (including whether new onset or pre-existing) and 28-day mortality, in addition to other biochemical markers. Pharmacological treatment regimes for rate or rhythm control of AF were also reviewed.
Results: The overall mortality rate was 19.9%. About 56% of patients had sepsis. Over a quarter of patients in the cohort (27.6%) were identified as having either new or pre-existing AF; a quarter of these had NOAF, and three quarters had pre-existing AF. Patients with AF had a higher mortality rate than patients without AF. Furthermore, patients with NOAF had a higher mortality rate than patients with pre-existing AF. The prevalence of DIC was higher in patients with new onset AF than in patients with
pre-existing AF. The mean age of patients with new or pre-existing AF was higher than those without AF and APACHE II scores were similarly higher in patients with AF. The majority of patients were given amiodarone to treat new onset AF.
Conclusions: New-onset atrial fibrillation is more common in older patients with higher APACHE II scores, and these patients have a higher 28-day mortality rate than patients with pre-existing AF. Patients with NOAF also had higher rates of DIC. Further research is needed to clarify the best treatment strategy for new onset AF in critically ill patients and to further investigate the link between the presence of coagulopathy and the development of AF.
References
1. Bosch NA, Cimini J, Walkey AJ. Atrial Fibrillation in the ICU. Chest. 2018;154(6):1424–34
2. Walkey AJ, Hogarth DK, Lip GYH. Optimizing Atrial Fibrillation Management – From ICU and Beyond. Chest. 2015;148(4):859–64
3. Klein Klouwenberg PM, et al. Incidence, Predictors, and Outcomes of New-Onset Atrial Fibrillation in Critically Ill Patients with Sepsis. A Cohort Study. Am J Respir Crit Care Med. 2017;195(2):205–11
4. National Institute for Health and Care Excellence (NICE) Clinical guideline 180: Atrial Fibrillation, 2014.
