Table 3. Baseline characteristics—aortic root surgery.

Variable	TRR			VSRR
	Pooled estimate	Range		Pooled estimate	Range
Total patient number	7,629	40–675		4,777	32–430
Surgical period	1968–2012			1988–2012
Total follow-up (patient-years)	49,175			21,716
Mean follow-up (years)	6.4	3–10.4		4.4	1.5–13.2
Mean age (years)	50	29–65		51	29–63
Male (%)	76	55–91		71	57–85
Aortic valve haemodynamics (%)
Stenosis
Regurgitation				46*	6–100
Mixed disease
Type A dissection (%)	15	0–39		11	0–33
Endocarditis (%)	2	0–15
Connective tissue disease (%)	23	0–100		24	0–100
Bicuspid aortic valve (%)	25	4–100		14	0–33
Prior cardiac operation (%)	16	1–7		4	2–12
Mechanical valve (%)	93	43–100
Concomitant surgery (%)
CABG	12	0–31		9	0–19
Valve surgery	6	0–12		5	0–12
(Hemi)arch	12	0–39		22	0–68

*, severe AR is reported. TRR, total root replacement; VSRR, valve-sparing root replacement; Range, range of the means of included studies; CABG, coronary artery bypass grafting.