Table 1. Baseline data
|
POAF group (n=68)
|
Control group (n=134)
|
p value
|
Age (years)
|
72.3 ± 10.8
|
72.7 ± 10.2
|
0.768
|
Male
|
36 (52.9%)
|
72 (53.7%)
|
0.915
|
Body mass index (kg/m2)
|
23.2 ± 4.3
|
22.8 ± 3.2
|
0.498
|
Preoperative complicated diseases
|
|
|
|
Chronic heart failure a
|
1 (1.5%)
|
6 (4.5%)
|
0.486
|
Hypertension
|
39 (57.4%)
|
82 (61.2%)
|
0.599
|
Coronary heart disease
|
18 (26.5%)
|
33 (24.6%)
|
0.776
|
Diabetes mellitus
|
9 (13.2%)
|
25 (18.7%)
|
0.330
|
Chronic obstructive pulmonary disease
|
3 (4.4%)
|
3 (2.2%)
|
0.674
|
Asthma
|
3 (4.4%)
|
5 (3.7%)
|
>0.999
|
Chronic kidney disease b
|
4 (5.9%)
|
9 (6.7%)
|
>0.999
|
Non-AF arrhythmia c
|
4 (3.0%)
|
7 (10.3%)
|
0.066
|
Preoperative echocardiographic abnormality
|
|
|
|
Left atrial enlargement
|
19 (35.8%)
|
22 (24.7)
|
0.157
|
Pulmonary arterial systolic pressure (mmHg)
|
32.6 ± 10.1
|
30.8 ± 11.0
|
0.195
|
Left ventricular ejection fraction <50%
|
6 (11.1%)
|
10 (10.6)
|
0.929
|
Cardiac valves abnormality
|
52 (98.1%)
|
86 (96.6)
|
>0.999
|
Preoperative ASA classification
|
|
|
0.498
|
I
|
23 (34.3%)
|
37 (27.4%)
|
|
II
|
26 (38.8%)
|
67 (49.6%)
|
|
III
|
11 (16.4%)
|
21 (15.6%)
|
|
IV
|
7 (10.2%)
|
10 (7.4%)
|
|
Duration from surgery to interview (month)
|
36.6 ± 1.3
|
36.3 ± 0.9
|
0.086
|
Data are presented as mean ± SD or number (%).
POAF: postoperative atrial fibrillation; AF: atrial fibrillation; ASA: American Society of Anesthesiologist.
a Diagnosed according to the symptoms and signs of heart failure, including dyspnea, inability to lie flat at night, decreased activity tolerance, peripheral edema, signs of pulmonary congestion on chest X-ray, and/or elevated serum brain natriuretic peptide level. These symptoms and signs developed on the basis of underlying heart diseases. Diagnosis was confirmed by cardiologists and treatment was required before surgery.
b Glomerular filtration rate <60 ml/min/1.73 m2 lasting for more than 3 months. Diagnosis was confirmed by nephrologists.
c Included sinus tachycardia (2 cases), sinus bradycardia (2 cases), atrial premature beat (2 cases), ventricular premature beat (1 case), supraventricular tachycardia (1 case), atrioventricular block (2 cases), and bundle branch block (1 case). Diagnosis was confirmed by preoperative electrocardiographic examination.
Table 2. Perioperative data
|
POAF group (n=68)
|
Control group (n=134)
|
P value
|
Type of surgery
|
|
|
0.995
|
Intra-abdominal
|
41 (60.3%)
|
84 (62.7%)
|
|
Intra-thoracic
|
14 (20.6%)
|
27 (20.1%)
|
|
Transurethral
|
2 (2.9%)
|
3 (2.2%)
|
|
Intra-cranial
|
3 (4.4%)
|
6 (4.4%)
|
|
Spinal and extremital
|
8 (11.8%)
|
14 (10.4%)
|
|
Duration of surgery (min)
|
196 (131, 357)
|
202 (147, 333)
|
0.966
|
Complexity of surgery a
|
|
|
0.907
|
Intermediate
|
3 (4.2%)
|
4 (3.0%)
|
|
Major or complex
|
65 (95.6%)
|
130 (97.0%)
|
|
Cardiac risk of surgery b
|
|
|
0.930
|
Low
|
3 (4.4%)
|
6 (4.5%)
|
|
Intermediate
|
64 (94.1%)
|
125 (93.3%)
|
|
High
|
1 (1.5%)
|
3 (2.2%)
|
|
Type of anesthesia
|
|
|
0.639
|
Neuraxial
|
8 (11.8%)
|
22 (16.4%)
|
|
General
|
56 (82.4%)
|
106 (79.1%)
|
|
Combined epidural-general
|
4 (5.9%)
|
6 (4.5%)
|
|
Intraoperative fluid balance
|
|
|
|
Fluid infusion (ml)
|
2750 (1862, 4263)
|
2300 (1600, 3925)
|
0.162
|
Blood transfusion
|
24 (35.3%)
|
43 (32.1%)
|
0.648
|
Emergency operation
|
21 (30.9%)
|
19 (14.2%)
|
0.005
|
ICU admission with intubation
|
45 (66.2%)
|
85 (63.4%)
|
0.700
|
APACHE II score at ICU admission c
|
12 (9,17%)
|
10 (8,13%)
|
0.003
|
Laboratory test results during ICU stay d
|
|
|
|
Hemoglobin (g/L)
|
98.9 ± 20.0
|
107.7 ± 18.8
|
0.003
|
Cardiac troponin I (ng/ml)
|
0.03 (0.01, 0.13)
|
0.01 (0.01, 0.02)
|
<0.001
|
Brain natriuretic peptide (pg/ml)
|
510 (186, 1194)
|
164 (90, 410)
|
<0.001
|
Serum potassium (mmol/L)
|
3.9 ± 0.6
|
4.2 ± 0.5
|
<0.001
|
Serum magnesium (mmol/L)
|
0.87 ± 0.16
|
0.94 ± 0.16
|
0.005
|
Data are presented as number (%), median (interquartile range) or mean ± SD.
POAF: postoperative atrial fibrillation; ICU: intensive care unit; APACHE II: Acute Physiology and Chronic Health Evaluation II.
a Rated according to routine preoperative tests for elective surgery: summary of updated National Institute for Health and Care Excellence (NICE) guidance [24].
b Rated according to American College of Cardiology/American Heart Association guideline update for perioperative cardiovascular evaluation for noncardiac surgery [25].
c The worst score within 24 hours after ICU admission.
d The last one before POAF in the POAF group. The worst one after ICU admission in the control group.
Table 3. Pathological diagnoses
|
POAF group
(n = 68)
|
Control group
(n = 134)
|
P value
|
Pathologically diagnosed cancer
|
48 (70.6%)
|
110 (82.1%)
|
0.061
|
TNM stage of cancer a
|
(n = 48)
|
(n = 110)
|
|
T stage
|
|
|
0.126
|
T0
|
0 (0.0%)
|
0 (0.0%)
|
|
T1
|
5 (10.4%)
|
27 (24.5%)
|
|
T2
|
12 (25.0%)
|
31 (28.2%)
|
|
T3
|
22 (45.8%)
|
40 (36.4%)
|
|
T4
|
9 (18.8%)
|
12 (10.9%)
|
|
N stage
|
|
|
0.176
|
N0
|
26 (54.2%)
|
77 (70.0%)
|
|
N1
|
13 (27.1%)
|
23 (20.9%)
|
|
N2
|
5 (10.4%)
|
7 (6.4%)
|
|
N3
|
4 (8.3%)
|
3 (2.7%)
|
|
M stage
|
|
|
0.514
|
M0
|
41 (85.4%)
|
98 (89.1%)
|
|
M1
|
7 (14.6%)
|
12 (10.9%)
|
|
Cancer stage a
|
(n = 48)
|
(n = 110)
|
0.135
|
Stage 1
|
5 (10.4%)
|
26 (23.6%)
|
|
Stage 2
|
21 (43.8%)
|
51 (46.4%)
|
|
Stage 3
|
15 (31.3%)
|
21 (19.1%)
|
|
Stage 4
|
7 (14.6%)
|
12 (10.9%)
|
|
Data are presented as number (%).
POAF: postoperative atrial fibrillation; TNM: tumor, node and metastasis.
a Rated according to the American Joint Committee on Cancer (AJCC) Cancer Staging Manual-7th Edition [26].
Table 4. 3-year outcomes
|
POAF group (n=68)
|
Control group (n=134)
|
Estimated effects (95% CI)
|
P value
|
Primary endpoint
|
|
|
|
|
MACEs within 3 years after surgery
|
44 (64.7%)
|
31 (23.1%)
|
OR=6.091 (3.215-11.543)
|
<0.001
|
Cardiovascular death a
|
8 (11.8%)
|
10 (7.5%)
|
OR=1.653 (0.621-4.403)
|
0.311
|
Nonfatal cardiac arrest b
|
4 (5.8%)
|
3 (2.2%)
|
OR=2.729 (0.593-12.560)
|
0.228
|
Acute myocardial infarction c
|
17 (25.0%)
|
20 (14.9%)
|
OR=1.900 (0.919-3.927)
|
0.080
|
Congestive heart failure d
|
32 (47.1%)
|
10 (7.5%)
|
OR=11.022 (4.947-24.559)
|
<0.001
|
Ischemic stroke e
|
6 (8.8%)
|
3 (2.2%)
|
OR=4.226 (1.023,17.456)
|
0.032
|
Secondary endpoints
|
|
|
|
|
MACEs in hospital after surgery
|
38 (55.9%)
|
10 (7.55%)
|
OR=15.707 (7.039-35.049)
|
< 0.001
|
Cardiovascular death a
|
1 (1.5%)
|
0 (0.0%)
|
---
|
---
|
Nonfatal cardiac arrest b
|
2 (2.9%)
|
2 (1.5%)
|
OR=2.000 (0.276-14.516)
|
0.604
|
Acute myocardial infarction c
|
12 (16.9%)
|
5 (3.7%)
|
OR=5.529 (1.860-16.434)
|
0.001
|
Congestive heart failure d
|
30 (44.1%)
|
8 (6.0%)
|
OR=12.434 (5.261-39.388)
|
< 0.001
|
Ischemic stroke e
|
1 (1.5%)
|
0 (0.0%)
|
---
|
---
|
Other postoperative complications in hospital
|
47 (69.1%)
|
25 (18.7%)
|
OR=9.758 (4.976-19.136)
|
< 0.001
|
Respiratory failure f
|
11 (16.2%)
|
1 (0.7%)
|
OR=25.667(3.237-203.505)
|
< 0.001
|
Severe sepsis or septic shock g
|
25 (36.8%)
|
10 (7.5%)
|
OR= 7.209 (3.203-16.226)
|
< 0.001
|
Circulatory insufficiency h
|
14 (20.6%)
|
12 (9.0%)
|
OR=2.636 (1.144-6.075)
|
0.020
|
New-onset arrhythmia (non-atrial fibrillation) i
|
27 (39.7%)
|
7 (5.2%)
|
OR=11.948 (4.844-29.468)
|
< 0.001
|
Acute kidney injury j
|
19 (27.9%)
|
3 (2.2%)
|
OR=16.932 (4.798-59.758)
|
< 0.001
|
Mechanical ventilation time k (hour)
|
36.0 (5.5, 168.5) (n=45)
|
7.0 (4.0, 13.5) (n=85)
|
Median D=29.0 (19.4, 41.7)
|
< 0.001
|
LOS in ICU after surgery (day)
|
5.0 (3.0, 11.0)
|
1.0 (1.0, 2.3)
|
Median D=4.0 (1.1, 10.4)
|
< 0.001
|
LOS in hospital after surgery (day)
|
17.5 (13.0, 31.0)
|
11.5 (8.0, 18.3)
|
Median D=6.0 (2.2, 13.1)
|
< 0.001
|
All-cause mortality in hospital
|
6 (8.5%)
|
1 (0.7%)
|
OR=13.015 (1.535, 110.325)
|
0.006
|
3-year overall survival after surgery (month)
|
25.8 (22.6, 28.9)
|
31.4 (30.1, 32.8)
|
HR=1.598 (1.007-2.538)
|
0.043
|
Data are expressed as n (%) or median/mean (95% CI).
POAF: postoperative atrial fibrillation; CI: confidence interval; MACEs: major adverse cardiovascular events; OR: odds ratio; D; difference; LOS: length of stay; ICU: intensive care unit; HR: hazard ratio; ICD-10: the International Classification of Diseases-10th revision.
a Any death caused by specific cardiovascular diseases (myocardial infarction [I21.X in the ICD-10 code], heart failure [I50.X], arrhythmia [I49.900], and cardiogenic shock [R57.001]), which might be combined with other diseases.
b Cardiac arrest (ventricular fibrillation, pulseless ventricular tachycardia, asystole, and pulseless electrical activity) caused by various reasons, followed by return of spontaneous circulation after cardiopulmonary resuscitation, and patient survived (I46.9).
c Diagnosed when the CTnI concentration was higher than the diagnostic criteria for myocardial infarction, together with the emergence of new Q wave (≥0.03 s) or the persistent change of ST-T segment (≥4 days) (I21.X).
d The acute attack or aggravation of the symptoms or signs of heart failure, accompanied by serum brain natriuretic peptide elevation (>400 pg/ml), and required medical treatment (I50.X).
e A new-onset, persistent (>24 hours) focal neurologic deficit with computed tomography or magnetic resonance imaging evidence of cerebral infarction (I63.9).
f Diagnosed when PaO2 <60 mmHg (room air), oxygenation index <300, and/or arterial oxygen saturation <90%, and required oxygen therapy or mechanical ventilation for more than 48 hours.
g Systematic inflammatory response syndrome caused by a known or suspected infection, accompanied by at least one new organ dysfunction or required vasopressor therapy to maintain blood pressure.
h Requirement of vasopressors and/or inotropic therapy for more than 24 hours.
i New-onset arrhythmia other than atrial fibrillation. Diagnosis was confirmed by a 12-lead electrocardiogram. Medical treatment and/or electrical conversion were required.
j Serum creatinine increased to more than 26.5 nmol/L within 48 hours after surgery, or serum creatinine increased to more than 1.5 times baseline within 7 days, or urine output <0.5 ml/kg/hr for more than 6 hours.
k Results of those who were admitted to the ICU with endotracheal intubation.
Table 5. Factors in association with 3-year MACEs a
|
Univariate analysis
|
Multivariate analysis b
|
OR (95% CI)
|
p value
|
OR (95% CI)
|
p value
|
New-onset POAF
|
6.091 (3.215-11.543)
|
<0.001
|
5.448 (2.202-13.481)
|
<0.001
|
Preoperative coronary heart disease
|
1.942 (1.019-3.703)
|
0.044
|
2.974 (1.126-7.858)
|
0.028
|
Preoperative non-AF arrhythmia c
|
4.935 (1.267-19.225)
|
0.021
|
---
|
---
|
Left atrial enlargement
|
2.307 (1.102-4.831)
|
0.027
|
---
|
---
|
Emergency operation
|
3.733 (1.814-7.683)
|
<0.001
|
---
|
---
|
APACHE II score at ICU admission
|
1.065 (1.008-1.125)
|
0.025
|
---
|
---
|
Hemoglobin <110 g/L
|
2.606 (1.368-4.965)
|
0.004
|
---
|
---
|
Cardiac troponin I >0.04 ng/ml
|
12.675 (5.759-27.894)
|
<0.001
|
19.137 (5.642-64.909)
|
<0.001
|
Brain natriuretic peptide >100 pg/ml
|
5.483 (2.199-13.667)
|
<0.001
|
---
|
---
|
Other complications in hospital (within 30 days) d
|
4.115 (2.230-7.585)
|
<0.001
|
---
|
---
|
MACEs: major adverse cardiovascular events; OR: odds ratio; CI: confidence interval; POAF: postoperative atrial fibrillation; AF: atrial fibrillation; APACHE II: Acute Physiology and Chronic Health Evaluation II; ICU: intensive care unit.
a Include cardiovascular death, nonfatal cardiac arrest, acute myocardial infarction, congestive heart failure, and ischemic stroke.
b Factors with p<0.10 in univariate analyses are included in the multivariate Logistic regression model. Multivariate Logistic regression analysis was performed by using a Backward (Wald) stepwise procedure. Hosmer-Lemeshow test: χ2=4.207, df=6, p=0.649.
c Includes sinus tachycardia (2 cases), sinus bradycardia (2 cases), atrial premature beat (2 cases), ventricular premature beat (1 case), supraventricular tachycardia (1 case), atrioventricular block (2 cases), and bundle branch block (1 case).
d Include respiratory failure, severe sepsis or septic shock, circulatory insufficiency, new-onset non-AF arrhythmia, and acute kidney injury.