|Year : 2018 | Volume
| Issue : 4 | Page : 127-131
Incidence of atrial fibrillation and risk factors analyzing in 126 cases of aortic surgery
Yaping He1, Hao Peng2, Kaitao Jian2, Qingzhi Li2, Wei Liu2, Yanlin Li1
1 Department of Cardiology, Deltahealth Hospital, Shanghai, China
2 Department of Cardiovascular Surgery, Deltahealth Hospital, Shanghai, China
|Date of Web Publication||19-Dec-2018|
Department of Cardiology, Deltahealth Hospital, No. 109 Xule Road, Shanghai 201702
Source of Support: None, Conflict of Interest: None
Objective: This study aims to determine the current incidence of atrial fibrillation postaortic repair surgery and further identify its clinical predictors. Patients and Methods: Over a 17-month period starting on September 1, 2016, and ending on January 31, 2018, diverse types of aortic surgery were performed on 126 consecutive patients (age range, 8–75 years and median age, 43 years) with aneurysm (n = 67) or dissection (n = 59) of the ascending, arch, thoracic, or abdominal aorta. Totally 41 patients received operations on an emergency basis because of acute Type A dissection. Potential predictors of postoperative atrial fibrillation (POAF) were estimated by a logistic regression model. Results: The incidence of postoperative new onset of atrial fibrillation (AF) was 26.2% (n = 33). Patients who developed POAF were more likely to be of advanced age (51 ± 16 vs. 40 ± 14, P < 0.01), and female patients were more likely to develop POAF compared with male patients (48.5% vs. 26.9%, P = 0.02). Patients with cardiac dysfunction (39.4% vs. 10.8%, P < 0.01), and those who underwent operations on the ascending aorta (48.5% vs. 29.0%, P = 0.04) were also more likely to develop POAF. Multivariate logistic regression analysis revealed that only advanced age and cardiac dysfunction were independent predictors of POAF (P = 0.029, odds ratio [OR] = 1.01, 95% confidence interval [CI]: 0.001–0.012; P = 0.003, OR = 1.34, 95% CI: 0.103–0.487). Conclusions: The prevalence of POAF is not rare in terms of patients undergoing aortic repair surgeries. Perioperative heart failure and increasing age may be correlating risk factors.
Keywords: Aortic surgery, heart failure, postoperative atrial fibrillation, risk factors
|How to cite this article:|
He Y, Peng H, Jian K, Li Q, Liu W, Li Y. Incidence of atrial fibrillation and risk factors analyzing in 126 cases of aortic surgery. Cardiol Plus 2018;3:127-31
| Introduction|| |
Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery. The development of this atrial arrhythmia prolongs hospital stay and is associated with a worse long-term prognosis. Atrial fibrillation (AF) occurs in 15%–40% of patients in the early postoperative period following coronary artery bypass graft surgery (CABG).,,, AF occurs in 37%–50% of patients after valvular surgery,,, and as many as 60% undergoing valve replacement plus CABG., Although the pathophysiological mechanisms responsible for the high incidence of AF after cardiac surgery remain unclear, it is thought to be related to a combination of preoperative factors, including preexisting degenerative changes in the atrial myocardium and perioperative conditions. These potential risk factors include increasing age, mitral valvular disease, increased left atrial size, cardiomegaly, previous cardiac surgery, chronic obstructive pulmonary disease, and among others.,,
However, the frequency and risk factors for AF after aortic repairs are not well characterized.
The number of aortic surgical repair procedures has been increasing in recent years due to increasing incidence of aortic dissection and aneurysm, most likely related to high prevalence of hypertension, atherosclerosis, and so on. Although there are minimal observational data demonstrating the prevalence of POAF after aortic surgical repairs, there are even less investigations exploring its correlated risk factors. Thus, this study aims to determine the current incidence of AF after aortic repair surgery and further identify its clinical predictors.
| Patients and Methods|| |
In this study, we report clinical data for a total of 126 consecutive patients with aortic aneurysm (n = 67) or aortic dissection (n = 59) who underwent aortic reconstruction surgery in the same institution between September 2016 and January 2018. Patients with persistent AF before surgery (n = 2) and patients who expired before surgery (n = 2) or during or immediately after the surgical intervention (n = 5) were excluded. Patients with incomplete electrocardiogram (EKG) data (n = 1) were excluded from the study. All patients operated on as elective or emergency aortic repair were included in the study. Totally 40 patients received surgery on an emergency basis due to acute Type A aortic dissection. Baseline demographic and clinical data were available for all patients. Initial data were collected from the medical records.
Based on diseased segments of aorta, the repair procedures included Bentall procedure, David repair, total arch repair, hemiarch repair, Sun's procedure, and thoracoabdominal aortic replacement. Of the 126 patients who met the inclusion criteria, 88 had surgery involving the ascending aorta, 61 had surgery involving the aortic arch, and 29 had thoracoabdominal aortic replacement.
Medical records, including EKGs and telemetry strips, were reviewed. The major outcome measure for this study was the development of postoperative AF. The postoperative AF was defined as an acute sustained episode requiring intervention within the 7-day period after surgery. Baseline demographic and clinical data were collected, including age, sex, hypertension, Marfan syndrome, chronic obstructive pulmonary disease or chest deformity, renal insufficiency, left ventricular ejection fraction, left atrial size, left ventricular end-diastolic diameter, and B-type natriuretic peptide (BNP). The relationship of POAF to perioperative parameters was assessed.
All values are expressed as the mean ± standard deviation or percentages. Differences between patient groups were tested by univariate analysis (Chi-square test or two-tailed t-test as appropriate). Findings of P < 0.05 were considered statistically significant; P < 0.01 was considered very statistically significant. Multiple logistic regression models were used to determine predictors of POAF based on baseline characteristics. The model included variables selected based on clinical importance or a significant relationship to the incidence of postoperative AF on univariate analysis. All analyses were performed using SPSS statistical software (version 23.0 software, Chicago, IL, USA).
| Results|| |
The demographics, perioperative and surgical data and outcomes are presented in [Table 1]. The mean age of the 126 study patients (85 men and 41 women) was 43 ± 15 years. Twenty patients (15.9%) had hypertension, and 50 patients (67.5%) had Marfan syndrome. Four patients (3.2%) had a history of valvular disease, 3 (2.4%) had chronic renal dysfunction, and 10 (7.9%) had chronic obstructive pulmonary disease or chest deformity. The in-hospital mortality rate was 3.8% (5 of 126). Operative indications included aortic aneurysm in 67 (53.2%) and aortic dissection in 59 patients (46.8%). Thirty-nine (31.0%) of the patients underwent redo aortic procedures. A total of 131 patients underwent surgeries and the postoperative mortality during hospital was 3.8%.
Thirty-three patients had AF postoperatively. The incidence of the postoperative new-onset AF, including both temporary and persistent, was 26.2% (33 of 126). No patients remained in AF at the time of discharge. All 33 patients who developed AF returned to sinus rhythm, with 31 receiving drug cardioversion and 2 receiving direct current cardioversion. The intensive care unit stay time and postoperative stay time showed no significant difference between patients with or without postoperative AF.
Perioperative variables stratified by the presence or absence of postoperative AF are shown in [Table 2]. The patients who had preoperative AF were excluded from this analysis. Univariate analysis suggested that age, female sex, perioperative heart failure, and ascending aorta involving procedures were significantly associated with postoperative AF. Hypertension, Marfan's syndrome, aortic arch repair, thoracoabdominal aortic repair, left ventricular end-diastolic diameter, left atrial size, and left ventricular ejection fraction did not show significant association with postoperative AF. Reoperation tended to be a negative predictor, but this variable was not statistically significantly associated with increased risk of postoperative AF (P = 0.06). Patients with abrupt onset symptoms and those who underwent emergency surgery tended to develop postoperative AF, but again this was not a statistically significant finding (P = 0.05).
A multivariate logistic regression model was developed to examine the predictors for AF. The variables used were those that showed statistically significant associations on univariate analysis. The results are shown in [Table 3]. Age (P = 0.029) and perioperative heart failure (P = 0.003) were independent predictors of AF, whereas female sex (P = 0.124), ascending aorta involving procedure (P = 0.388), and emergency surgery (P = 0.839) did not achieve statistical significance.
| Discussion|| |
The present data indicate that new-onset postoperative AF occurs in approximately 26.2% of patients undergoing aortic repair surgeries. There is only one large sample analysis referring to POAF in patients undergoing aortic surgery in the literature in recent years. Arakawa et al. analyzed 12,260 records of thoracic aortic surgery cases and reported the incidence of POAF at 17.1%. Comparing with this, the incidence we reported is slightly higher. Besides our small sample size, there is great disparity in baseline demographic parameters between the two studies, with higher percentages of reoperation (31% vs. 9.5%), Marfan's syndrome (67.5% vs. not mentioned), root and ascending aorta procedure (69.8% vs. 56.6%), and lower percentages of hypertension (15.9% vs. 77.6%) in our study. Above all, we conclude that new-onset AF after aortic surgery is not uncommon; the incidence is lower than that reported after CABG and valve surgery but higher than the incidence after major noncardiothoracic surgeries. Brathwaite and Weissman documented new-onset atrial arrhythmias in 10.2% of 462 consecutive patients undergoing a variety of vascular, abdominal, and orthopedic operations. Arakawa et al. reported that the incidence of POAF was closely related to the location of the aortic lesion. The percentage of occurrence of POAF was 20.4% with root procedures, 21.2% with ascending procedures, 20.9% with arch procedures, 10.5% with descending procedures, and 8.5% with thoracoabdominal procedures. Aortic surgery is generally more invasive than CABG and valvular replacement. Open surgical repair of the thoracic aorta often requires cardiopulmonary bypass with a cardioplegia-arrested heart, and specific circulatory measures to protect the brain, spinal cord, kidneys, viscera, and lower extremities. Despite this, the incidence of POAF after aortic repair is lower than that after CABG and valve replacement. According to Arakawa's et al. report, the nearer the diseased aorta to the heart, the higher the incidence of POAF. Importantly, descending and thoracoabdominal aortic replacement usually does not require cardiac arrest; therefore, patients who undergo these surgeries are less likely to acquire POAF. In addition, patients with diseased root and ascending aorta are more likely to have aortic valve regurgitation and cardiac dysfunction, which may further predispose to the development of POAF.
Previous evidence suggested that POAF is associated with prolonged hospital stay and increased mortality for patients undergoing CABG or valvular replacement.,,,, New-onset AF added approximately 6 days to the hospital duration in the EXCEL trial of patients with left main coronary artery disease. Postoperative AF may identify a subset of patients with increased in-hospital and long-term mortality.,,,,, This was suggested by a retrospective study of 6475 patients undergoing CABG at a single institution, 15% of whom developed AF. Patients with AF had a significantly higher mortality rate of in-hospital (7.4% vs. 3.4%) and at 4 years' postoperatively (26% vs. 13%). Our findings indicate that there were no differences in duration of Intensive Care Unit stay or postoperative hospitalization between patients with and without POAF. We did not analyze differences in mortality between patients with and without POAF due to limited sample size and short observation period. Therefore, further investigation is needed to elucidate the potential adverse outcomes after the development of POAF for aortic surgery, include stroke, death, and prolongation of hospital stay.
The underlying mechanisms involved in POAF development are multifactorial and are currently far from being fully elucidated. Mechanisms including pericardial inflammation, excessive catecholamine production, autonomic imbalance during the postoperative period, and interstitial mobilization of fluid may alter atrial refractoriness and reduce atrial conduction., However, numerous studies have proposed a number of additional preoperative risk factors,,,,,, including increasing age, previous history of AF, mitral stenosis, increased left atrial size, obesity, absence or withdrawal of beta-blocker treatment, higher preoperative plasma BNP, and low-dose dopamine. Perioperative risk factors,, include pericarditis, atrial injury, inflammation, and hyperadrenergic state. Our data revealed that advanced age and perioperative heart failure are independent predictors of POAF after aortic surgery. Increasing age has been confirmed as a traditional risk factor for the development of AF by numerous studies. In this study, heart failure was defined as BNP > 400 pg/ml regardless of the situation of cardiac structure and systolic function. Heart failure here is referred to as ejection fraction preserved heart failure (HFpEF) because cardiomegaly and decreased ejection fraction is not suggested in our data. AF is very common in people with HFpEF, being noted at some point in roughly two-thirds of patients. The underlying pathophysiological mechanism is considerably complicated. Slowed, incomplete myocardial relaxation causes increased left atrium pressure and impairs left atrial function.
| Conclusions|| |
We have reported results from the first single-center cohort of Chinese patients and POAF development after aortic surgery. By retrospectively analyzing, 126 procedures indicated by aortic dissection or aneurysm, our data suggested that AF is a common postoperative complication of aortic surgery with the incidence of 26.2%. Advanced age and perioperative heart failure are independent predictors for POAF. These results will contribute to exploring potential key risk factors associated with POAF. Further studies are warranted to determine whether prophylactic strategies to prevent POAF may improve prognosis in patients with great artery disease who are undergoing repair surgery.
Several limitations exist in this study. First, the observational data, we analyzed came from a single-center and cannot be assumed as representative cases in other centers in China. Second, we did not analyze differences in mortality between the patients with and without postoperative AF due to the relatively small size and short observation period. Third, preoperative pharmacological therapy such as beta-blockers was not included in the logistic regression analysis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]