Med Princ Pract: risk factor for new-onset atrial fibrillation during thyroid surgery

Background: Atrial fibrillation (AF) is one of
the most common arrhythmias that require treatment.
The prevalence of this arrhythmia increases with age; Among people under 55 years of age, 0.
1% of people develop atrial fibrillation, while in 9%
of people aged 80 years and older.
It is associated with
increased morbidity and prolonged hospital stay, as well as higher treatment costs for these patients.
Complications, particularly thromboembolic complications such as ischaemic stroke and transient ischaemic attack (TIA), are more common in patients with AF, resulting in higher
perioperative mortality.
The absolute risk of ischaemic stroke or TIA at 5 years in patients with perioperative atrial fibrillation was significantly higher than in patients without atrial fibrillation, up to 10.
7%.

Similarly, the risk of all-cause death has been reported in patients with atrial fibrillation than in patients
without atrial fibrillation.
The incidence of atrial fibrillation is highest in cardiac surgery; Patients undergoing valve surgery (up to 52.
7%) were higher than those undergoing coronary artery bypass grafting (CABG) (27%)
.
It is also one of the most common complications in thoracic surgery, with reported rates ranging from
12.
3% to 38%.
Atrial fibrillation occurs relatively rarely in non-cardiothoracic surgery (ophthalmology 0.
37%, plastic surgery 3.
1 - 14.
1%, neurological surgery 6.
4%, genitourinary 69%, vascular surgery 14%, large colorectal surgery about 9 - 13%)
.

The underlying cause of atrial fibrillation is not fully understood
.
Some of the mechanisms described include intraoperative phenomena such as inflammation, sympathetic activation, and cardiac ischemia that co-cause atrial fibrillation, often in the presence of pre-existing factors, making the atria susceptible to atrial fibrillation induction and maintenance
.
In addition, intraoperative electrophysiological disturbances, metabolic imbalances, hypoxia, hyperglycemia/hypoglycemia, and hypervolemia can also cause AF.

Thyroid dysfunction is known to be a common cause of atrial fibrillation, and previous studies have shown a significantly higher
incidence of atrial fibrillation in patients with expressed hyperthyroidism and subclinical hyperthyroidism.
However, there are few
data on the development of atrial fibrillation in patients with normal thyroid function who undergo thyroid surgery.

Purpose: Therefore, the aim of our study is to determine the prevalence and predictors
of new-onset atrial fibrillation (NOAF) in these patients.

Subjects and methods: The study included 1252 patients with normal thyroid function with ASA 2 and ASA 3 physiological states of the American Society of Anesthesiologists (ASA), aged 18 years and older, with normal sinus rhythm
.
Patients with no comorbidities and persistent atrial fibrillation were excluded
.
We investigated the effects of the following preoperative features on the development of NOAF: age, sex, body mass index, ASA score, diagnosis of admission, and comorbidities
.
We looked at the effects
of endotracheal intubation difficulties, type of surgery, duration of surgery, and time to general anaesthesia.
Univariate and multivariate logistic regression was used to determine the predictors
of NOAF occurrence.

Results: NOAF
occurred in 0.
72% of patients.
People with NOAF were older than those without NOAF (63.
11 years vs.
56.
81 years), but this was not statistically significant
.
Compared with those who did not register NOAF, there were significantly more patients with preoperative heart rhythm disturbances and angina pectoris in the NOAF group (p = 0.
001; P = 0.
017)
。 Multivariate analysis showed that a history of heart rate disorders was an independent predictor
of NOAF.

Table 1 Features of patients with or without NOAF

Table 2 Univariate logistic regression analysis

Table 3 Multivariate logistic regression analysis

Conclusion: The incidence of NOAF in thyroid surgery is similar
to other types of surgery in the setting of normal thyroid hormones.

Original source:

Stojanovic M, Kalezic N, Milicic B,et al.
Risk Factors for New Onset Atrial Fibrillation During Thyroid Gland Surgery.
Med Princ Pract 2022 Oct 21