Recommendations from a Review and Analysis of Strategies for Prediction, Prevention and Management of Post-operative Atrial Fibrillation after Non-cardiac Thoracic Surgery.

Background:

Atrial fibrillation (AF) is the most commonly sustained arrhythmia after non-cardiac thoracic surgery, occurring between 12%-44% of pulmonary and esophageal resections, and is associated with a significant increase in post-operative morbidity, length of stay (LOS), intensive care unit (ICU) admission and mortality ([i],[ii]). Patients who develop postoperative atrial fibrillation (POAF) often experience an increased LOS of 2 to 14 days ([iii]). If sustained, it can increase the patient’s risk of thromboembolic events ([iv]). As an independent risk factor of stroke in the 30 days following development of new sustained AF ([v]), anticoagulation is critical ([vi]). AF is associated with increased mortality risk after esophagectomy (mortality increase from 4.8 to 8.1%, p=0.04) ([vii]) and decreased long-term survival after lobectomy (HR 3.75; 95% CI 1.44 to 9.08) (1). AF is both common and impactful, efforts to effectively and optimally predict, prevent and manage POAF is critical to improving quality of thoracic surgical care.

Our review and analysis aimed to provide a practical, feasible and clinically applicable strategy for the prediction, prevention and management of POAF in patients undergoing non-cardiac thoracic surgery. Below are the recommendations developed from our review and analysis, as well as an algorithm to guide individualized evidence-based management of POAF.

Recommendation

1. Multiple existing predictive models are capable of identifying patients at increased risk for POAF; however clinical application of these risk models first requires external validation, followed by ongoing evaluation and improvement over time.
2. Prophylactic therapy with beta-blocker agents, amiodarone, calcium-channel blockers (CCB) and magnesium may be considered to reduce the risk of POAF; however, providing prophylaxis to all patients is not recommended because the exposure of all patients to the risk of adverse events outweighs the benefit experienced by only a few patients in preventing POAF. The approach of implementing prophylaxis only in high-risk patients only to reduce incidence and severity of POAF is promising yet unproven, and requires further study to evaluate safety and effectiveness.
3. For patients with new onset POAF who develop acute hemodynamic instability, immediate synchronized electrocardioversion is recommended and consideration of echocardiogram.
4. Hemodynamically stable patients with POAF should receive incremental dosing of rate control therapy with continuous cardiac monitoring until a heart rate of <110 BPM is achieved. If the patient has known decompensated heart failure or ejection fraction <35%, consider the least negatively inotropic agent, namely amiodarone. If no decompensated heart failure, initial trial of low trial dose of beta-blocker (e.g. 2 mg metoprolol IV push) should be given followed by repeat dosing if beneficial effect witnessed (e.g. lowering HR) and no adverse events (e.g. hypotension, bronchospasm, bradycardia) until desired effect; or if no effect observed on heart rate or blood pressure, consider CCB (e.g. 5 mg diltiazem IV push), with repeat dosing if beneficial effect and no adverse events to achieve rate control.
5. To augment effect of either beta-blocker or CCB, consider digoxin to further augment effectiveness of rate control and minimize adverse events.
6. Early assessment and correction of underlying POAF triggers may help facilitate early return to sinus rhythm (such as pneumothorax, pneumonia, pulmonary embolism, infection, bleeding or electrolyte abnormalities).
7. Cardioversion should be reserved for patients who cannot tolerate rate control agents or who, after 48h, continue to have POAF despite rate control.
8. The choice of antiarrhythmic agent should be selected in accordance with the patient’s comorbidities and the agents side effect profile.
9. Further formal evaluations of standardized protocols to predict, prevent and manage POAF are warranted to evaluate impact on incidence, duration and severity of POAF.
10. Antithrombotic therapy to reduce the risk of stroke in patients with persistent AF should be considered if POAF persists >48h, and should be individualized based on patient’s risk factors for thromboembolic event (congestive heart failure, hypertension, diabetes, previous thromboembolic event, peripheral vascular disease) and post-operative bleeding risk.

Abbreviations: POAF, post-operative atrial fibrillation; CCB, calcium channel blocker; BPM, beats per minute.

Abbreviations: IV, intravenous; O2, oxygen; ECG, electrocardiogram; CBC, complete blood count; LOC, level of consciousness; HR, heart rate; HF, heart failure; EF, ejection fraction, CHF, congestive heart failure; HTN, hypertension; DM, diabetes mellitus; TIA, transient ischemic attack, CXR, chest x-ray; TEE, trans-esophageal echocardiogram; LMWH, low molecular weight heparin; ASA, acetylsalicylic acid.

References

[i] Imperatori, A., Mariscalco, G., Riganti, G., et al. (2012b). Atrial fibrillation after pulmonary lobectomy for lung cancer affects long-term survival in a prospective single-center study. Journal of Cardiothoracic Surgery, 7, 4. https://doi.org/10.1186 /1749-8090-7-4

[ii] Amar D, Zhang H, Shi W, et al. Brain natriuretic peptide and risk of atrial fibrillation after thoracic surgery. The Journal of Thoracic and Cardiovascular Surgery. 2012 Nov 1;144(5):1249–53.

[iii] Polanczyk, C.A., Goldman, L., Marcantonio, E.R., et al. Supraventricular arrhythmia in patients having non cardiac surgery: clinical correlates and effect on length of stay. The Annals of Internal Medicine. 1998; 129: 279–285

[iv] Investigators, T. A. F. F. I. of R. M. (AFFIRM). (2002). A Comparison of Rate Control and Rhythm Control in Patients with Atrial Fibrillation. New England Journal of Medicine, 347(23), 1825–1833. https://doi.org/10.1056/NEJMoa021328

[v]  Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomised controlled trial. The Lancet. 2008 May 31;371(9627):1839–47.

[vi]  Camm, A.J., Lip G.Y.H, De Caterina R., et al. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation An update of the 2010 ESC Guidelines for the management of atrial fibrillation Developed with the special contribution of the European Heart Rhythm Association. Europace. 2012 Oct 1;14(10):1385–413.

[vii] Rao, V. P., Addae-Boateng, E., Barua, A., et al. (2012). Age and neo-adjuvant chemotherapy increase the risk of atrial fibrillation following oesophagectomy. European Journal of Cardio-Thoracic Surgery, 42(3), 438–443. https://doi.org/10.1093/ejcts /ezs085

Authors:
H Smith, MD ; C, Yeung, MD2; S Gowing, MD2; MM Sadek, MD, FRCPC3; DE Maziak, MD, FRCSC2; S Gilbert, MD, FRCSC2; FM Shamji MD, FRCSC2; PJ Villeneuve, MD, FRCSC2; RS Sundaresan MD FRCSC2, AJE Seely MD, PhD, FRCSC
[1] Division of General Surgery, The Ottawa Hospital, University of Ottawa
[2] Division of Thoracic Surgery, The Ottawa Hospital, University of Ottawa
[3] Division of Cardiology, The Ottawa Hospital, University of Ottawa

Correspondence to:
Heather Smith
Department of Surgery, Division of General Surgery, The Ottawa Hospital
501 Smyth Rd, Ottawa, ON K1H 8L6
Email: hesmith@toh.ca
Telephone: (613) 789-5555

Author’s Contribution:
(II) Administrative support: HS
(III) Provision of study materials or patients: NA
(IV) Collection and assembly of data: HS, AS, MS, FS, DM, SS, AS
(V) Data analysis and interpretation: HS, AS, MS, FS, DM, SS, AS
(VI) Manuscript writing: All authors
(VII) Final approval of manuscript: All authors