Biological versus mechanical prosthesis in 3279 patients from the Swedish in-patients register

Figures & data

Figure 1. Overall survival in relation to age and type of prosthesis in 3279 patients who underwent heart valve surgery 1985–2003. Black vertical bars = Mechanical<70 years. Black circles = Biological <70 years. Grey vertical bars = Mechanical ≥70 years. Grey circles = Biological ≥70 years.

Table I. Linearized rates (per patient year) of prosthesis-related complications and number of patients with repeated events (n = 3279).

	Mechanical prosthesis		Biological prosthesis
Complication	events	% ppy	events	% ppy	p-value
All patients	n = 2176		n = 1103
Thromboembolism	248	1.5	142	2.6	p < 0.001
Hemorrhage	271	1.7	57	1.1	p = 0.002
Endocarditis	79	0.5	44	0.8	p = 0.005
Patients <70	n = 1747		n = 173
Thromboembolism	190	1.5	21	2.8	p = 0.005
Hemorrhage	200	1.5	8	1.0	p = 0.3
Endocarditis	61	0.5	11	1.4	p = 0.0003
Patients >70	n = 547		n = 1031
Thromboembolism	58	1.7	121	2.6	p = 0.01
Hemorrhage	71	2.1	49	1.1	p = 0.0001
Endocarditis	15	0.5	31	0.7	p = 0.2
Repeated events*	Mechanical prosthesis		Biological prosthesis
Patients <70	2 events	3 or more events	2 events	3 or more events
Thromboembolism	17	12	4	0
Hemorrhage	19	14	1	0
Patients >70
Thromboembolism	11	2	9	4
Hemorrhage	6	4	4	2

*number of patients with repeated events.

ppy, per patient year.

Table II. Number of first events and relative hazards associated with a mechanical prosthesis versus bioprosthesis; multivariate analysis* based on the study cohort (n = 3279).

	Number of first events
	Age <70	RH (C.I.)	Age >70	RH (C.I.)
Biological prosthesis	67	ref	350	ref
Mechanical prosthesis
Mortality	419	0.6 (0.4–0.8)	211	0.9 (0.7–1.1)
Thromboembolism	140	0.5 (0.3–0.9)	42	0.5 (0.4–0.8)
Bleeding	111	1.3 (0.6–2.7)	54	1.9 (1.3–3.2)
Any event	575	0.5 (0.4–0.7)	244	0.9 (0.7–1.0)

RH, relative hazard; C.I., confidence interval.

Table III. Comparison of relative hazards at <5 years, 5–10 years, and >10 years after heart valve surgery, in patients with a mechanical prosthesis. Reference is patients with bioprosthesis in the corresponding time interval.

	<5 years		5–10 years		>10 years
	R.H.	C.I.	R.H.	C.I.	R.H.	C.I.
Bleeding
Age <70 years	2.0	0.8–4.8	1.2	0.5–2.7	0.9	0.4–2.1
Age >70 years	4.9	2.9–8.4	1.6	1.0–2.7	1.2	0.6–2.6
Thromboembolism
Age <70 years	1.0	0.5–2.0	0.7	0.4–1.2	0.3	0.2–0.6
Age >70 years	1.2	0.6–2.2	0.5	0.3–0.7	0.3	0.2–0.6

RH, relative hazard; C.I., confidence interval.

Figure 2. Event-free survival in relation to age and type of prosthesis in 3279 patients who underwent heart valve surgery during 1985–2003. Vertical black bars = Mechanical <70 years. Black circles = Biological <70 years. Vertical grey bars = Mechanical ≥70 years. Grey circles = Biological≥70 year.