New-onset of postoperative atrial fibrillation is likely to recur in the absence of other triggers

Figures & data

Table 1 Baseline and postoperative characteristics in relation to peri-procedural (≤7 days) new-onset AF among patients undergoing cardiac surgery in the LAACS study

Variable	No AF (n=83)	New-onset AF (n=80)	p-value
Age, years	65.3±10.1	70.5±7.7	<0.001
Male	71 (85.5)	66 (82.5)	0.60
Clinical characteristics
Congestive heart failure	13 (15.7)	15 (18.8)	0.65
Diabetes	22 (26.5)	21 (26.3)	0.96
Hypertension	60 (72.3)	63 (78.8)	0.32
CHA2DS2-VASc, unit	2.7±1.5	3.3±1.4	0.01
Prior stroke	9 (10.8)	14 (17.5)	0.27
Chronic kidney diseasea	9 (10.8)	17 (21.3)	0.13
Medicine
ASA	68 (81.9)	67 (83.8)	0.86
Clopidogrel	16 (19.3)	12 (15.0)	0.55
Beta blocker	48 (57.8)	49 (61.3)	0.75
Verapamil	2 (2.4)	2 (2.5)	1.00
Calcium blocker	18 (21.7)	32 (40.0)	0.01
RAS blocker	46 (55.4)	37 (46.3)	0.27
Discharged with OAC	20 (24.1)	31 (38.8)	0.04
Statin	70 (84.3)	67 (83.8)	0.97
Procedural characteristics
Left atrial appendage closure (randomized)	51 (61.4)	32 (40.0)	0.02
Surgery type
AVR only	11 (13.3)	15 (18.8)	0.34
AVR with CABG	13 (16.3)	21 (26.3)	0.09
AVR with aortic surgery	1 (1.2)	1 (1.3)	1.00
AVR with MVR	1 (1.2)	1 (1.3)	1.00
Aortic surgery only	1 (1.2)	0 (0)	1.00
CABG only	52 (62.7)	34 (42.5)	0.01
CABG with MVR	2 (2.4)	1 (1.3)	0.58
MVR only	2 (2.4)	7 (8.8)	0.13
Tricuspid surgery only	0 (0)	0 (0)	1.00

Notes:

a eGFR<30 mL/min. Data presented as n (%) or mean ± SD.

Abbreviations: AF, atrial fibrillation; ASA, acetyl salicylic acid; AVR, aortic valve replacement; CABG, coronary artery bypass grafting; CHA₂DS₂-VASc, congestive heart failure, hypertension, age (≥75 years), diabetes, stroke – peripheral vascular disease, age (≥65 years), sex category; eGFR, estimated glomerular filtration rate; LAACS, Left Atrial Appendage Closure with Surgery; MVR, mitral valve repair or replacement; OAC, oral anticoagulation; RAS, renin–angiotensin system.

Table 2 Univariate and multivariate predictors of POAF: within the first 7 days following cardiac surgery in the LAACS studya

Variable	Univariate			Multivariate
	χ^2	OR	p-value	χ^2	OR	p-value
Age	11.9	1.07 (95% CI 1.03–1.11)	<0.001	3.9	1.05 (95% CI 1.00–1.09)	0.03
Male gender	0.3	0.80 (95% CI 0.34–1.85)	0.60	–	–	–
CHA2DS2-VASc	6.4	1.33 (95% CI 1.07–1.67)	0.01	–	–	–
Beta blocker	0.1	1.11 (95% CI 0.59–2.10)	0.75	–	–	–
Calcium blocker	6.5	2.48 (95% CI 1.23–5.00)	0.01	6.0	2.69 (95% CI 1.22–5.92)	0.01
RAS blocker	1.2	0.70 (95% CI 0.38–1.31)	0.27	–	–	–
Statin	0.0	0.99 (95% CI 0.43–2.28)	0.97	–	–	–
LAACS (randomized)	5.7	0.46 (95% CI 0.24–0.87)	0.02	6.3	0.40 (95% CI 0.19–0.82)	0.01
Surgery typeb	7.0	2.37 (95% CI 1.25–4.47)	0.01	4.2	2.11 (95% CI 1.04–4.30)	0.04

Notes:

a ORs for postoperative (within the first 7 days following cardiac surgery) new-onset AF (yes/no). Multivariate ORs reflect the predictors that remained significant at a 95% significance level when including all predictors with a univariate p<0.70 (to remove irrelevant parameters) in stepwise selection.

b “Valve” (aortic [n=26] or mitral valve replacement [n=8]) or “vessel and valve surgery” (aortic valve replacement with CABG [n=32], aortic valve replacement with aortic repair [n=2], aortic and mitral valve replacement [n=2] or mitral valve replacement with CABG [n=3]) as compared to “vessel only” (aortic repair [n=1] or CABG [n=86]).

Abbreviations: AF, atrial fibrillation; CABG, coronary artery bypass grafting; CHA₂DS₂-VASc, congestive heart failure, hypertension, age (≥75 years), diabetes, stroke – peripheral vascular disease, age (≥65 years), sex category; LAACS, Left Atrial Appendage Closure with Surgery; OR, odds ratio; POAF, perioperative AF; RAS, renin–angiotensin system.

Figure 1 Breakdown of all AF events in the main LAACS cohort.

Note: Occurrence of perioperative AF, and occurrence of late AF are marked in bold.
Abbreviations: AF, atrial fibrillation; LAACS, Left Atrial Appendage Closure with Surgery.

Table 3 Proportion of patients meeting end points according to peri-procedural new-onset AF: during a mean follow-up of 3.7 years in the LAACS study

End point	No AF (n=83)	New-onset AF (n=80)	HR	p-value
Late AF	6 (7.2%)	35 (43.8%)	9.3 (95% CI 3.8–22.4)	<0.001
All-cause mortality	5 (6.0%)	9 (11.3%)	2.3 (95% CI 0.7–6.9)	0.15
AF/deatha	11 (13.3%)	41 (51.3%)	6.0 (95% CI 3.0–12.0)	<0.001

Note:

a Composite end point of first of late AF or death.

Abbreviations: AF, atrial fibrillation; HR, hazard ratio; LAACS, Left Atrial Appendage Closure with Surgery.

Table 4 Univariate and multivariable predictors of late AF (after 90 days) following cardiac surgery: during a mean follow-up of 3.7 years in the LAACS studya

Variable	Univariate			Multivariable
	χ^2	HR	p-value	χ^2	HR	p-value
Age	2.5	1.03 (95% CI 0.99–1.06)	0.11	–	–	–
Male gender	0.2	0.82 (95% CI 0.38–1.78)	0.62	–	–	–
CHA2DS2-VASc	2.8	1.21 (95% CI 0.97–1.51)	0.09	–	–	–
Beta blocker	0.4	1.22 (95% CI 0.64–2.31)	0.55	–	–	–
Calcium blocker	1.1	1.40 (95% CI 0.74–2.66)	0.30	–	–	–
RAS blocker	2.1	1.60 (95% CI 0.85–3.01)	0.15	6.8	2.48 (95% CI 1.25–4.90)	0.01
Statin	0.8	0.71 (95% CI 0.33–1.54)	0.39	–	–	–
LAACS (randomized)	0.3	0.85 (95% CI 0.45–1.61)	0.62	–	–	–
Surgery typeb	7.2	2.42 (95% CI 1.27–4.60)	0.01	6.0	2.36 (95% CI 1.19–4.67)	0.01
New-onset AF (n=80)c	26.4	9.27 (95% CI 3.84–22.39)	,0.001	22.4	8.86 (95% CI 3.59–21.89)	<0.001
No AF (n=83)d	NA	Reference	NA	NA	Reference	NA
Only peri-procedural AF (n=37)d	13.0	6.88 (95% CI 2.41–19.67)	<0.001	11.7	5.90 (95% CI 2.13–16.37)	0.01
Peri-procedural and early AF (n=43)d	29.7	15.78 (95% CI 5.85–42.56)	<0.001	27.0	12.24 (95% CI 4.76–31.45)	<0.001

Notes:

a HRs for late (90 days after cardiac surgery) AF (yes/no). Multivariable HRs reflect the predictors that remained significant at a 95% significance level when including all predictors with a univariate p<0.70 (to remove irrelevant parameters) in stepwise selection.

b “Valve” (aortic [n=26] or mitral valve replacement [n=8]) or “vessel and valve surgery” (aortic valve replacement with CABG [n=32], aortic valve replacement with aortic repair [n=2], aortic and mitral valve replacement [n=2] or mitral valve replacement with CABG [n=3]) as compared to “vessel only” (aortic repair [n=1] or CABG [n=86]).

c Peri-procedural new-onset AF within the first 7 days after surgery (yes/no).

d No AF, no peri-procedural or early AF; only peri-procedural AF, peri-procedural AF but no AF occurrence within 90 days; peri-procedural and early AF, peri-procedural and recurrence of AF within 90 days. Three patients died within the first 90 days and were censored for late AF at the time of death according to peri-procedural new-onset AF.

Abbreviations: AF, atrial fibrillation; CABG, coronary artery bypass grafting; CHA₂DS₂-VASc, congestive heart failure, hypertension, age (≥75 years), diabetes, stroke – peripheral vascular disease, age (≥65 years), sex category; HR, hazard ratio; NA, not applicable; LAACS, Left Atrial Appendage Closure with Surgery; RAS, renin–angiotensin system.

Figure 2 Cumulative probability of late AF (after 90 days) according to peri-procedural new-onset AF.

Abbreviation: AF, atrial fibrillation.

Figure 3 Cumulative probability of late AF (after 90 days) according to peri-procedural new-onset AF with or without early AF recurrence (within 90 days).

Abbreviation: AF, atrial fibrillation.

Table S1 Univariate and multivariable predictors of late AF (after 90 days) or death following cardiac surgery: during a mean follow-up of 3.7 years in the LAACS studya

Variable	Univariate			Multivariable
	χ^2	HR	p-value	χ^2	HR	p-value
Age	1.8	1.02 (95% CI 0.99–1.05)	0.18	–	–	–
Male gender	0.2	0.96 (95% CI 0.47–1.96)	0.90	–	–	–
CHA2DS2-VASc	1.8	1.14 (95% CI 0.94–1.38)	0.18	–	–	–
Beta blocker	0.8	1.30 (95% CI 0.73–2.32)	0.37	–	–	–
Calcium blocker	0.9	1.31 (95% CI 0.74–2.34)	0.85	–	–	–
RAS blocker	2.7	1.61 (95% CI 0.91–2.85)	0.10	8.2	2.43 (95% CI 1.32–4.47)	0.004
Statin	0.3	0.81 (95% CI 0.39–1.66)	0.56	–	–	–
LAACS (randomized)	0.3	0.86 (95% CI 0.49–1.51)	0.60	–	–	–
Surgery typeb	8.0	2.27 (95% CI 1.29–3.98)	0.004	7.3	2.32 (95% CI 1.26–4.27)	0.007
New-onset AFc	26.4	6.03 (95% CI 3.04–11.97)	<0.001	24.9	6.37 (95% CI 3.08–13.20)	<0.001

Notes:

a HRs for late (90 days after cardiac surgery) AF (yes/no). Multivariable HRs reflect the predictors that remained significant at a 95% significance level when including all predictors with a univariate p<0.70 (to remove irrelevant parameters) in stepwise selection.

b “Valve” (aortic [n=26] or mitral valve replacement [n=8]) or “vessel and valve surgery” (aortic valve replacement with CABG [n=32], aortic valve replacement with aortic repair [n=2], aortic and mitral valve replacement [n=2] or mitral valve replacement with CABG [n=3]) as compared to “vessel only” (aortic repair [n=1] or CABG [n=86]).

c Peri-procedural new-onset AF within the first 7 days after surgery (yes/no).

Abbreviations: AF, atrial fibrillation; CABG, coronary artery bypass grafting; CHA₂DS₂-VASc, congestive heart failure, hypertension, age (≥75 years), diabetes, stroke – peripheral vascular disease, age (≥65 years), sex category; HR, hazard ratio; NA, not applicable; LAACS, Left Atrial Appendage Closure with Surgery; RAS, renin–angiotensin system.