Preoperative atrial fibrillation in association with reduced haemoglobin predicts increased 30-d mortality after cardiac surgery

Abstract

Objectives: Atrial fibrillation is the most common arrhythmia occurring after cardiac surgery. Less attention has been focused on preoperative atrial fibrillation and anaemia as risk factors for mortality after cardiac surgery. The aim of this study was to determine preoperative risk factors for 30-d mortality after open-heart surgery. Design. The study population consisted of 2015 patients (73.4% men; mean age 68 years) undergoing coronary artery bypass grafting (CABG) (52.0%), aortic valve replacement (AVR) (18.6%), AVR and CABG (10.0%), mitral valve plasty or replacement (14.0%), and AVR and aortic root reconstruction (ARR) (5.5%) in Kuopio University Hospital from January 2013 to December 2016. Univariate and multivariate Cox proportional hazards models were used for statistical analyses. Kaplan–Meier survival curves were generated. Results. Total 30-d mortality was 1.8%. By Cox regression analysis, predictors of 30-d mortality (hazard ratio [HR] [95% confidence interval [CI]]) included female gender (1.95 [1.00–3.77]), preoperative atrial fibrillation, (2.38 [1.12–5.03]) reduced haemoglobin level (3.40 [1.47–7.90]), and pulmonary congestion (3.16 [1.52–6.55]). The combination of preoperative reduced haemoglobin and preoperative atrial fibrillation was a strong predictor (12.37 [4.40–34.77], p