Table 4.

Subgroup analyses and meta-regression for the risk of atrial fibrillation recurrence after catheter ablation associated with metabolic syndrome and its component factors

Exposures	Variables	Subgroup	No. of studies	Pooled estimates	p values for association	p values for heterogeneityb	p values from meta-regression
Metabolic syndrome	Mean age	Low (<median)	2	3.03 (1.70–5.40)	<0.001	0.394	0.083
		High (≥median)	3	1.39 (1.19–1.62)	<0.001	0.482
HTN	Adjustment for other MetS components	No adjustment	7	1.62 (1.23–2.13)	0.001	0.085	Ref
		Adjusted for 1 additional component	5	1.30 (1.00–1.70)	0.05	0.118	0.286
		Adjusted for ≥2 additional components	5	1.08 (0.94–1.24)	0.295	0.454	0.042
	CFAE	No	10	1.54 (1.24–1.92)	<0.001	0.053	0.043
		Yes	7	1.12 (0.96–1.30)	0.15	0.272
	Linear ablation	No	6	1.40 (1.09–1.78)	0.007	0.282	0.511
		Yes	11	1.29 (1.08–1.54)	0.005	0.015
Obesity/overweighta	Proportion of HTN	Low (< median)	3	2.32 (1.20–4.50)	0.013	0.138	0.048
		High (≥median)	3	1.09 (0.97–1.23)	0.15	0.666
	Adjustment for OSA	No	5	1.29 (0.98–1.70)	0.071	0.006	0.852
		Yes	1	1.24 (0.53–2.90)	0.62	–
	Report of follow-up length	No	2	2.97 (1.61–5.50)	0.001	0.267	0.025
		Yes	4	1.10 (0.97–1.23)	0.135	0.826
DM	Adjustment for other MetS components	No adjustment	1	3.25 (1.21–8.72)	0.019	–	Ref
		Adjusted for 1 additional component	3	1.20 (0.87–1.64)	0.263	0.011	0.102
		Adjusted for ≥2 additional components	6	1.07 (0.95–1.20)	0.29	0.897	0.074
Dyslipidemia	Timing of recurrence assessment	Investigated very late recurrence (>12 months)	1	4.01 (1.84–8.73)	<0.001	–	0.026
		Investigated recurrence after 2–3 months	5	1.00 (1.00–1.00)	0.994	0.429

BMI body mass index, HTN hypertension, CFAE (ablation of) sites with complex fractionated atrial electrograms, DM diabetes mellitus, Ref reference group, OSA obstructive sleep apnea

^aAs defined in the original articles: BMI≥25 [6, 8, 11, 13] and BMI≥30 [12, 24]

^bCochrane Q test for heterogeneity