Role of a new inflammation predictor in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation

Table 1 Baseline characteristics of study population

Characteristics	All patients (n = 457)	Patients without recurrence (n = 344)	Patients with recurrence (n = 113)	P value
Age (years)	61.32 ± 9.97	60.92 ± 10.15	62.56 ± 9.33	0.128
Male sex	287 (62.8)	223 (64.8)	64 (56.6)	0.145
BMI (kg/m2)	25.68 ± 3.44	25.71 ± 3.51	25.57 ± 3.24	0.683
Hypertension	221 (48.4)	161 (46.8)	60 (53.1)	0.245
Diabetes mellitus	87 (19)	65 (18.9)	22 (19.5)	0.893
Stroke/TIA	49 (10.7)	40 (11.6)	9 (8)	0.275
Heart failure	44 (9.6)	31 (9)	13 (11.5)	0.436
Smoking	78 (17.1)	60 (17.4)	18 (15.9)	0.711
NPAF	144 (31.5)	92 (26.7)	52 (46)	< 0.001
CHA2DS2-VASc score	2.09 ± 1.61	2.04 ± 1.62	2.22 ± 1.59	0.32
APPLE	1.004 ± 0.95	0.88 ± 0.86	1.37 ± 1.08	< 0.001
LVEF (%)	62.48 ± 7.35	62.74 ± 7.18	61.69 ± 7.82	0.187
LAD (mm)	39.3 ± 5.52	38.71 ± 5.42	41.08 ± 5.45	< 0.001
LVDD (mm)	49.91 ± 4.38	49.85 ± 4.18	50.11 ± 4.94	0.58
TC (mmol/L)	4.38 ± 1.01	4.35 ± 1.00	4.45 ± 1.07	0.409
TG (mmol/L)	1.60 ± 1.11	1.60 ± 1.04	1.62 ± 1.3	0.856
LDL (mmol/L)	2.6 ± 0.91	2.56 ± 0.88	2.69 ± 0.98	0.200
HDL (mmol/L)	1.15 ± 0.31	1.15 ± 0.33	1.15 ± 0.24	0.86
Glucose (mmol/L)	5.6 ± 1.74	5.6 ± 1.8	5.61 ± 1.53	0.978
BNP (pg/mL)	98 (51, 158)	93 (46.25, 155.5)	130 (61, 186.5)	0.022
eGFR (mL/min/1.73 m2)	94.91 ± 14.18	95.72 ± 14.02	92.44 ± 14.43	0.033
Uric acid (μmol/L)	337.98 ± 90.37	338.91 ± 87.36	335.18 ± 99.33	0.704
Creatinine (mmol/L)	68.25 ± 51.62	68.54 ± 58.73	67.37 ± 16.9	0.834
White blood cell count (× 109/L)	6.15 ± 1.44	6.1 ± 1.41	6.3 ± 1.5	0.184
Neutrophils (× 109/L)	3.68 ± 1.15	3.6 ± 1.11	3.95 ± 1.26	0.005
Lymphocytes (× 109/L)	1.93 ± 0.58	1.97 ± 0.57	1.81 ± 0.58	0.012
Monocytes (× 109/L)	0.39 ± 0.26	0.4 ± 0.3	0.39 ± 0.11	0.722
Platelet count (× 109/L)	215.19 ± 53.3	214.87 ± 53.28	216.15 ± 53.59	0.824
SII	450.06 ± 234.47	428.36 ± 221.24	516.11 ± 260.91	0.002

Data were expressed as mean ± SD, median with 25^th and 75^th percentile or n (%). BMI: Body mass index; NPAF: Non-paroxysmal atrial fibrillation; LVEF: Left ventricular ejection fraction; LAD: Left atrial diameter; LVDD: Left ventricular end-diastolic diameter; TC: Total cholesterol; TG: Total glyceride; LDL: Low density lipoprotein cholesterol; HDL: High-density lipoprotein cholesterol; BNP: B-type natriuretic peptide; eGFR: Estimated glomerular filtration rate; SII: Systemic immune inflammation index.

Table 2 Univariate and multivariate Logistic regression analysis of atrial fibrillation recurrence

Risk factor	Univariate analysis		Multivariate analysis
	OR (95%CI)	P value	OR (95%CI)	P value
NPAF	2.335 (1.503-3.627)	< 0.001
APPLE	1.689 (1.351-2.112)	< 0.001	1.723 (1.338-2.219)	< 0.001
LAD	1.084 (1.041-1.129)	< 0.001
BNP	1.002 (1-1.003)	0.023	1 (0.998-1.002)	0.901
eGFR	0.985 (0.97-0.999)	0.035
Neutrophils	1.297 (1.08-1.557)	0.005
Lymphocytes	0.608 (0.412-0.899)	0.013
High SII	2.686 (1.637-4.406)	< 0.001	2.257 (1.219-4.179)	0.01

OR: Odds ratio; 95%CI: 95% confidence interval; NPAF: Non-paroxysmal atrial fibrillation; LAD: Left atrial diameter; BNP: B-type natriuretic peptide; eGFR: Estimated glomerular filtration rate.

Table 3 Measures of predictive accuracy and improvement using systemic immune inflammation index +APPLE score in prognostication of recurrent atrial fibrillation

		NRI	P value	IDI	P value
SII	APPLE	0.127	0.2347	0.014	0.341
SII	SII + APPLE	0.296	0.00392	0.049	< 0.001
APPLE	SII + APPLE	0.341	0.00037	0.035	< 0.001

IDI: Integrated discrimination improvement; NRI: Net reclassification improvement; SII: Systemic immune inflammation index.