Potentially modifiable risk factors for atrial fibrillation following lung resection surgery: a retrospective cohort study

Post-operative atrial fibrillation (POAF) is one of the most frequent complications of cardiac surgery and an important predictor of patient morbidity as well as of prolonged hospitalization. It significantly increases costs for hospitalization. Insights into the pathophysiological factors causing POAF have been provided by both experimental and clinical investigations and show that POAF is ‘multi-factorial’. Facilitating factors in the mechanism of the arrhythmia can be classified as acute factors caused by the surgical intervention and chronic factors related to structural heart disease and ageing of the heart. Furthermore, some proarrhythmic mechanisms specifically occur in the setting of POAF. For example, inflammation and beta-adrenergic activation have been shown to play a prominent role in POAF, while these mechanisms are less important in non-surgical AF. More recently, it has been shown that atrial fibrosis and the presence of an electrophysiological substrate capable of maintaining AF also promote the arrhythmia, indicating that POAF has some proarrhythmic mechanisms in common with other forms of AF. The clinical setting of POAF offers numerous opportunities to study its mechanisms. During cardiac surgery, biopsies can be taken and detailed electrophysiological measurements can be performed. Furthermore, the specific time course of POAF, with the delayed onset and the transient character of the arrhythmia, also provides important insight into its mechanisms. This review discusses the mechanistic interaction between predisposing factors and the electrophysiological mechanisms resulting in POAF and their therapeutic implications.

To (1) characterize atrial fibrillation complicating lung cancer resection, (2) evaluate its temporal relationship to other postoperative complications, and (3) assess its economics. From January 1998 to August 2002, 604 patients underwent anatomic lung cancer resection. Atrial fibrillation prevalence, onset, and temporal associations with other postoperative complications were determined. Propensity matching was used to assess economics. Atrial fibrillation occurred in 113 patients (19%), peaking on postoperative day 2. Older age, male gender, heart failure, clamshell incision, and right pneumonectomy were risk factors (P < .01). Although atrial fibrillation was solitary in 75 patients (66%), other postoperative complications occurred in 38. Respiratory and infectious complications were temporally linked with atrial fibrillation onset. In 91 propensity-matched pairs, patients developing atrial fibrillation had more other postoperative complications (30% vs. 9%, P < .0004), had longer postoperative stays (median 8 vs 5 days, P < .0001), incurred higher costs (cost ratio 1.8, 68% confidence limits 1.6-2.1), and had higher in-hospital mortality (8% vs 0%, P = .01). Even when atrial fibrillation was a solitary complication, hospital stay was longer (median 7 vs 5 days, P < .0001), and cost was higher (cost ratio 1.5, 68% confidence limits 1.2-1.6). Atrial fibrillation occurs in 1 in 5 patients after lung cancer resection, with peak onset on postoperative day 2. Risk factors are both patient and procedure related, and atrial fibrillation may herald other serious complications. Although often solitary, atrial fibrillation is associated with longer hospital stay and higher cost. It therefore requires prompt treatment and should stimulate investigation for other problems.

Background Atrial fibrillation (AF) after thoracic surgery is a continuing source of morbidity and mortality. The effect of postoperative AF on long-term survival however has not been studied. Our aim was to evaluate the impact of AF on early outcome and on survival > 5 years after pulmonary lobectomy for lung cancer. Methods From 1996 to June 2009, 454 consecutive patients undergoing lobectomy for lung cancer were enrolled and followed-up until death or study end (October 2010). Patients with postoperative AF were identified; AF was investigated with reference to its predictors and to short- and long-term survival (> 5 years). Results Hospital mortality accounted for 7 patients (1.5%), while postoperative AF occurred in 45 (9.9%). Independent AF predictors were: preoperative paroxysmal AF (odds ratio [OR] 5.91; 95%CI 2.07 to 16.88), postoperative blood transfusion (OR 3.61; 95%CI 1.67 to 7.82) and postoperative fibro-bronchoscopy (OR 3.39; 95%CI 1.48 to 7.79). Patients with AF experienced higher hospital mortality (6.7% vs. 1.0%, p = 0.024), longer hospitalization (15.3 ± 10.1 vs. 12.2 ± 5.2 days, p = 0.001) and higher intensive care unit admission rate (13.3% vs. 3.9%, p = 0.015). The median follow-up was 36 months (maximum: 179 months). Among the 445 discharged subjects with complete follow-up, postoperative AF was not an independent predictor of mortality; however, among the 151 5-year survivors, postoperative AF independently predicted poorer long-term survival (HR 3.75; 95%CI 1.44 to 9.08). Conclusion AF after pulmonary lobectomy for lung cancer, in addition to causing higher hospital morbidity and mortality, predicts poorer long-term outcome in 5-year survivors.