Role of gut microbiota in post-operative atrial fibrillation: a randomized trial of berberine

Post-operative atrial fibrillation (POAF) is one of the most common complications. However, the underlying factors governing POAF are not well understood. The aim of this study was to investigate the relationship between gut microbiota and POAF. Then, we conducted a randomized, double-blind, placebo-controlled trial with patients underwent isolated coronary artery bypass grafting (CABG) in China to measure gut microbiota altering and impact on the incidence of POAF by oral berberine. Compared with no-POAF patients, gut microbiota composition was significantly altered, including Veillonella increasing. The POAF incidence was reduced from 35–20% under the treatment of berberine. Oral berberine significantly decreased Veillonella abundances, and lipopolysaccharide (LPS), C-reactive protein (CRP) and Interleukin- 6 (IL-6) level. Elevated LPS after surgery is associated with POAF. Our results showed that POAF patients show significantly gut microbiota shift. Altering gut microbiota like oral berberine reduced the POAF.

512 Long-term survival in patients with post-operative atrial fibrillation after cardiac surgery: analysis from a prospective-cohort study

Aims Post-operative atrial fibrillation (POP AF) is frequent in patients who undergo cardiac surgery. However, its prognostic impact in the long-term remains unclear. Methods and results We followed for an average of 10 ± 3 years 1386 patients who underwent a variety of cardiac surgical procedures (cardiac transplantation and surgery for heart failure included) while they were in sinus rhythm. Among 1178 patents without a history of AF, 726 (62%) did not develop AF during the entire duration of the study and 452 (38%) developed new-onset POP AF during the first 30 peri-operative days after heart surgery. Other 125 patients with a positive history of paroxysmal or persistent AF were in sinus rhythm at the time of surgery and 87 of them (70%) developed POP AF. Finally, 83 patients had permanent AF when they underwent surgery. All-cause mortality was the primary outcome of the study. We tested the associations of potential determinants with all-cause mortality using univariable and multivariable statistical analyses by means of Cox proportional hazard models. Overall, 473 patients (34%) died during a long-term follow-up. Compared with patients who never developed AF, neither the patients with new-onset POP AF [adjusted HR = 1.31 (95% CI: 0.90–1.89); P = 0.1609], nor those with history of AF at the time of surgery (adjusted HR = 1.33, 95% CI: 0.71–2.49; P = 0.3736) showed a significantly increased risk of mortality (Figure 1). In new-onset POP AF patients, oral anticoagulation was not associated with mortality [adjusted HR = 1.13 (95% CI: 0.83–1.54), P = 0.4299]. Conclusions In this huge prospective cohort of patients who underwent different types of heart surgery, POP AF was not associated with an increased risk of mortality. In this setting, the role of long-term anticoagulation remains unclear.

Post-operative atrial fibrillation in off pump coronary artery bypass graft: association with medication

Background: Post-operative atrial fibrillation is a common post-operative complication and has significant morbidity and mortality. This study was done with an objective to determine the association of various medication use in patients undergoing coronary artery bypass graft (CABG) with post-operative atrial fibrillation (POAF).Methods: This was a prospective observational study done in the department of cardiovascular and thoracic surgery of GMC Kottayam from December 2019 to December 2020 after obtaining institutional review board clearance. A sample size of 334 was fixed and patients undergoing off pump (OP) CABG were consecutively recruited in the study. The association of intraoperative and postoperative medication use with occurrence of POAF were analysed using the univariate analysis with a p<0.05 using the SPSS 16 software.Results: Peri-operative inotrope use was found to be significantly associated with post operative atrial fibrillation odds ratio 1.08 (95% CI 1.02-1.13). We could not find any association with preoperative use of beta blockers/agonist, antidiabetics, levothyroxine, ACE inhibitors or antiplatelet drugs. All the patients 60 (18%) who developed POAF were given amiodarone as per protocol.Conclusions: Perioperative inotrope use was found to have significant association with the development of post operative atrial fibrillation following OPCABG. More multi-institutional studies with determination of association with individual drugs and doses with POAF need to be conducted in future.

Anticoagulation and bleeding events in Patients with Post- Operative Atrial Fibrillation After Cardiac Surgery

Background Post-operative atrial fibrillation (POPAF) following cardiac surgery is a common arrhythmia associated with an increased morbidity and mortality. There is little data evaluating the safety and effectiveness of anticoagulation (AC) in POPAF patients. We investigated the occurrence of 30-days POP major bleeding or embolic events and their timing in relation to the index cardiac surgery, the initiation of the arrhythmia and of anticoagulation in patients who developed new onset POPAF. Methods 4,073 consecutive patients undergoing cardiac surgery from September 2010- December 2016 were evaluated. Patients with history of AF/Aflutter were excluded. POPAF was confirmed by ECG or telemetry. Major post-operative bleeding that occurred after AF was defined using PLATO criteria or the BARC scale (any ≥3). Results 3,230 patients were included (37% CABG, 69% valve surgery). The incidence of POAF was 24%. The median time (IQR) of POPAF was 3 (2) days after the index surgery. 64% of POAF patients were male and 14% had a history of stroke. The mean (SD) age was 72 (9) years old. The average (SD) CHA2DS2-VASc score was 3.9 (1.5). The initial postoperative AC was full dose heparin, lovenox or argatroban in 58% of patients. The rest of patients had low dose heparin/lovenox for DVT prophylaxis and/or were started on oral anticoagulation without a bridge. The median (IR) time of POPAF to anticoagulation was 1 (2) days. There were 15 (1.9%) major bleeding events; 88% of which occurred in patients receiving full anticoagulation. Major bleeding events occurred a median of 15 (9) days after the index surgery and 9 (6) days after anticoagulation. Independent predictors of major bleed were history of PAD (P&lt;0.01) and pre-operative use of b-blockers (P=0.04). There were 11 (1.4%) POP strokes which occurred a median of 5 (16) days after the index surgery, and 2 (13) days after POPAF. 63% of strokes happened in patients that received anticoagulation. The mean CHA2DS2-VASc score were 3.9 (1.5) and 4.7 (1.7), P=0.1 for patients without and with strokes, respectively. Stroke history (P&lt;0.01) was the only independent stroke predictor. Both strokes and bleeding events were associated with significantly longer ICU and hospital length of stay. 86% of POPAF patients received amiodarone during hospitalization and 2.1% electric cardioversion. Upon discharge, 2.3% of patients were in in atrial fibrillation and 0.8% in atrial flutter. Conclusion The post-operative course of major bleeds and stroke in patients with POPAF after cardiac surgery is different. Bleeding events are delayed and appear related to anticoagulation. The relative benefit of perioperative anticoagulation remains unclear. FUNDunding Acknowledgement Type of funding sources: None.