Predictors of New Onset Atrial Fibrillation Burden in the Critically Ill.

INTRODUCTION: Atrial fibrillation (AF) is common in the intensive care unit (ICU) setting and has been associated with adverse outcomes. In this context, there is increasing research interest in AF burden as a predictor of subsequent adverse events. However, the pathophysiology and drivers of AF burden in the ICU are poorly understood. This study sought to evaluate the predictors of AF burden in critical illness-associated new-onset AF (CI-NOAF). METHODS: Out of 7,030 admissions in a tertiary general ICU between December 2015 and September 2018, 309 patients developed CI-NOAF. AF burden was defined as the percentage of monitored time in AF, as extracted from hourly interpretations of continuous ECG monitoring. Low and high AF burden groups were defined relative to the median AF burden. Clinical, laboratory, and echocardiographic parameters were extracted, and multivariable modelling with binary logistic regression was performed to evaluate for independent associations with AF burden. RESULTS: The median AF burden was 7.0%. Factors associated with increased AF burden were age, dyslipidaemia, chronic kidney disease, increased creatinine, CHA2DS2-VASc score, ICU admission diagnosis category, amiodarone administration, and left atrial area (LAA). Factors associated with lower AF burden were previous alcohol excess, burden of ventilation, the use of inotropes/vasopressors, and beta blockers. On multivariate analysis, increased LAA, chronic kidney disease, and amiodarone use were independently associated with increased AF burden, whereas beta blocker use was associated with lower AF burden. CONCLUSION: Left atrial size and chronic cardiovascular comorbidities appear to be the primary drivers of CI-NOAF burden, whereas factors related to acute illness and critical care intervention paradoxically did not appear to be a substantial driver of arrhythmia burden. Further research is needed regarding drivers of AF and the efficacy of rhythm control intervention in this unique setting.

The impact of maternal body mass index on the rate of obstetric anal sphincter injury in nulliparous women: A Victorian retrospective cohort study.

BACKGROUND: Maternal obesity is an important comorbidity in contemporary obstetrics practice and is associated with significantly increased perinatal complications. Obstetric anal sphincter injury (OASIS) sustained during labour can lead to faecal incontinence, chronic pain and effects on quality of life. Currently, it is unclear if maternal body mass index (BMI) influences the risk of sustaining OASIS. AIM: To investigate the impact of increased BMI on the rate of OASIS among nulliparous women. MATERIALS AND METHODS: A retrospective cohort study was conducted, which included nulliparous women with singleton, vaginal deliveries ≥37 weeks gestation at a Victorian regional centre between 2007 and 2017 (n = 3335). Logistic regression was performed to calculate unadjusted and adjusted odds ratios (aOR). Women were grouped by World Health Organization BMI categories, and the rates of OASIS were evaluated. RESULTS: Women with a BMI ≥ 25 were significantly less likely to develop OASIS compared to women with a BMI < 25 (aOR 0.60, 95% CI 0.41-0.89). Women with a BMI ≥ 35 had significantly decreased odds of OASIS compared to normal weight women (aOR 0.27, 0.10-0.78). While not statistically significant, the odds of OASIS decreased with each increase in BMI class. Other statistically significant risk factors were maternal age, birth weight, forceps delivery, non-smokers (aOR 4.03, 1.46-11.1) and diabetes mellitus (aOR 9.48, 2.1-41.4). CONCLUSION: Women with a BMI ≥ 25 were less likely to sustain OASIS compared to women with a BMI < 25. Furthermore, the odds of OASIS decreased for each increase in BMI category. These findings warrant further investigation into the mechanism of this protective effect.