Atrial Fibrillation in Patients Requiring Vasopressors After Coronary Bypass Grafting

Dear Editor;

We read with interest the paper by Paytes et al ¹ entitled “Impact of Intravenous Hydrocortisone on Postoperative Atrial Fibrillation and Outcomes in Patients Receiving Vasopressor Support Following On-Pump Coronary Artery Bypass Grafting.” We congratulate the authors. However, we would like to address some important issues about postoperative atrial fibrillation (PoAF) risk factor after coronary artery bypass graft (CABG) surgery.

In their retrospective single-center study, the authors investigated the effect of hydrocortisone treatment on PoAF in patients who underwent CABG and needed vasopressors over a period of ~2 years. At the end of the study, they concluded that intravenous hydrocortisone administration was not associated with the incidence of PoAF. ¹ While these findings are quite significant, the lack of use of known risk scoring systems for PoAF may be an important limiting factor. The use of many risk scoring systems is recognized in the literature. ²

PoAF after CABG operations can be affected by many factors related to coronary artery disease and surgery. It has been shown that the incidence of PoAF is more frequent in patients with extensive coronary artery disease. ³ It is also thought that clotted structures accumulating in the pericardial sac can lead to inflammation and be a trigger for PoAF. In this regard, a study including 25 randomized controlled trials concluded that performing posterior pericardiotomy in cardiac surgery operations reduced the incidence of PoAF. ⁴

One of the most important problems in retrospective PoAF studies is rhythm monitoring. Continuous rhythm monitoring increases the power of the studies. ⁵ PoAF usually occurs between the second and fourth days after these operations. Although continuous monitoring is done in intensive care follow-ups, continuous telemetry monitoring is not done in clinical follow-ups. It should be remembered that some PoAF attacks may be missed in patients who do not express complaints during these periods.

Renal insufficiency following cardiac surgery can occur to varying degrees. ⁶ In the current study, more than half of the patients had heart failure and all patients used vasopressor agents. Despite this, renal insufficiency developed in only 1 patient in the postoperative period. ¹ However, it has been shown that the use of norepinephrine increases the risk of renal injury after cardiac surgery operations. ⁷ Therefore, grading the clinical presentation of renal insufficiency may be useful.