Table 4:

Echocardiographic data

Echo data	Preoperative	Discharge	1 year	5 years
	n = 1608	n = 1228	n = 512	n = 197
Effective orifice area (cm2), mean (SD)	0.8 (0.3)	1.7 (0.6)	1.7 (0.5)	1.5 (0.4)
Mean gradient (mmHg), mean (SD)	45.8 (16.5)	13.3 (5.2)	11.9 (5.5)	13.7 (10.0)
Peak gradient (mmHg), mean (SD)	74.7 (25.9)	24.7 (10.5)	20.5 (8.9)	23.0 (15.0)

SD: standard deviation.