Background-:. The Medtronic-Hall (MH) valve was developed and for the first time implanted in Oslo in 1977. A total of 1,104 patients received this valve at Rikshospitalet-Radiumhospitalet HF in the period 1977-87. In the present study we followed all 816 patients undergoing aortic valve replacement (AVR) over a 25-year period.

The Medtronic-Hall (MH) tilting valve disk was first implanted in Oslo in June 1977. From 1977 through 1987, the valve was used as the only valve of choice and inserted in a total of 1,104 consecutive patients at our department.

The MH valve is made of a single piece of titanium with no welds. The disk is made of tungsten impregnated graphite with a carbon pyrolytic coating. The tungsten renders the disk radiopaque. In the aortic position the maximal opening is 75˚. A central aperture in the disk allows free rotation. The valve is rotatable in the sewing ring. The sewing ring is made of Teflon. Aortic sizes are 20-31 mm (outer diameter).

The initial clinical results were published in 1979 (1). The cohort of patients has been followed-up and analysed at 5, 10 and 15 years (2-5). In the present study we report our 25-year follow-up data for the 816 patients undergoing aortic valve replacement (AVR) with special reference to survival, functional status, valve-related complications and the impact of concomitant surgery.

Inclusion Criteria:

• All patients with aortic valve replacement 1977-87

All consecutive patients undegoing AVR during inclusion period