Postoperative Atrial Fibrillation and Long-Term Risk of Stroke in Patients Undergoing Liver Transplantation

Abstract

Background and Purpose: Postoperative atrial fibrillation (POAF) is the commonest cardiovascular complication following liver transplantation (LT). This study sought to assess a possible association of POAF with subsequent thromboembolic events in patients undergoing LT. Methods: A retrospective cohort study of consecutive adults undergoing LT between 2010 and 2018 was undertaken. Patients were classified as POAF if atrial fibrillation (AF) was documented within 30 days of LT without a prior history of AF. Cases of ischemic stroke or systemic embolism were adjudicated by a panel of 2 independent physicians. Results: Among the 461 patients included, POAF occurred in 47 (10.2%) a median of 3 days following transplantation. Independent predictors of POAF included advancing age, postoperative sepsis and left atrial enlargement. Over a median follow-up of 4.9 (interquartile range, 2.9–7.2) years, 21 cases of stroke and systemic embolism occurred. Rates of thromboembolic events were significantly higher in patients with POAF (17.0% versus 3.1%; P <0.001). After adjustment, POAF remained a strong independent predictor of thromboembolic events (hazard ratio, 8.36 [95% CI, 2.34–29.79]). Increasing CHA 2 DS 2 VASc score was also an independent predictor of thromboembolic events (hazard ratio, 1.58 [95% CI, 1.02–2.46]). A model using POAF and a CHA 2 DS 2 VASc score ≥2 alone yielded a C statistic of 0.77, with appropriate calibration for the prediction of thromboembolic events. However, POAF was not an independent predictor of long-term mortality. Conclusions: POAF following LT is associated with an 8-fold increased risk of thromboembolic events and the use of the CHA 2 DS 2 VASc score may facilitate risk stratification of these patients. Prospective studies are warranted to assess whether the use of oral anticoagulants can reduce the risk of thromboembolism following LT.

Predicting New-Onset Postoperative Atrial Fibrillation Following Isolated Coronary Artery Bypass Grafting: Development and Validation of a Novel Nomogram

“…17 , 18 Degeneration of the atrial myocardium with aging may lead to a loss of side-to-side electrical coupling between muscle fibers, slowing down electrical conduction of the sinoatrial and atrioventricular nodes and atria, thereby providing an anatomic or electrophysiologic substrate for arrhythmogenesis. 19 Left atrial (LA) enlargement is a manifestation of potentially fibrosis and adverse atrial remodeling, 20 in addition to age, it can also be exacerbated by atrial ischemia in the presence of stenosis of coronary artery supplying to the atria. 21 On the basis of varying degrees of changes in the atria, inflammation and activation of the autonomic nervous system are the principal transient factors associated with CABG that trigger POAF.…”

New onset atrial fibrillation during orthotopic liver transplantation induced by iced saline injection for transpulmonary thermodilution: a case report

“… 12 – 14 Postoperative AF was also associated with an 8-fold increased risk of stroke and systemic embolism events over a median follow-up of 4.9 years. 15 …”

“…Anticoagulant therapy was not considered in the present case, due to the following factors: First, the consideration of postoperative bleeding risk; Secondly, the CHA 2 DS 2 VASc score of the patient was 0. CHA 2 DS 2 VASc score has been well validated in assessing the risk of thromboembolism associated with AF, 9 and may also estimate the risk of stroke in patients with AF, with higher scores indicating a greater risk of stroke, 15 so the risk of a thromboembolic event was considered to be low in the present case; and Thirdly, a previously published study showed that early anticoagulant therapy did not improve clinical outcomes in critically ill patients with new onset AF, 30 and a systematic review didn’t support early anticoagulant therapy for new onset AF whilst patients are critically ill. 31 …”

“…[12][13][14] Postoperative AF was also associated with an 8-fold increased risk of stroke and systemic embolism events over a median follow-up of 4.9 years. 15 Autonomic imbalance, surgical stress, elevated catecholamine level, pre-existing pericardial inflammation, and cardiac malfunction are all factors attributed to the development of AF during liver transplantation. 16 Acidosis, hypo/hyperkalaemia, hypocalcaemia, hypoglycaemia, and hypothermia during liver transplantation may also induce AF, and higher MELD score and fulminant hepatic failure have been associated with the occurrence of intraoperative AF.…”

Review article: diagnosis, pathophysiology and management of atrial fibrillation in cirrhosis and portal hypertension

“…Both pre‐existing AF and new‐onset post‐operative AF after liver transplantation have been associated with adverse outcomes. The incidence of new‐onset AF in the post‐operative period was reported between 6.8% and 10.2% 8,66–68 . In a retrospective registry of 1387 patients who underwent liver transplantation, post‐operative AF, defined as new‐onset AF within 30 days of liver transplant, occurred in 7.4% of patients 66 .…”