TABLE 1. Prevalence of covariates
Covariates Hancock Standard (714 valves) Hancock II (1293 valves) P value

Male sex 340 (48%) 803 (62%) <.0001
Age, y (mean ± SD) 47.8 ± 11.9 67.5 ± 8.2 <.0001
NYHA class <.0001
 I 0 36 (3%)
 II 19 (3%) 506 (39%)
 III 580 (81%) 536 (41%)
 IV 108 (15%) 184 (14%)
Cardiogenic shock 6 (0.8%) 32 (3%) .01
Endocarditis 23 (3%) 48 (4%) .5
Diabetes 14 (2%) 53 (4%) <.009
Hypertension 39 (5.5%) 96 (7%) .04
Chronic renal failure 2 (0.3%) 43 (3%) <.0001
Emergent/urgent procedure 10 (1.4%) 65 (5%) <.0001
Previous cardiac operation 94 (13%) 160 (12%) .6
Mitral valve position 525 (73%) 484 (37%) <.0001
Aortic valve position 189 (26%) 809 (63%) <.0001
Valve pathology
 Rheumatic 498 (70%) 211 (16%) <.0001
 Degenerative 100 (14%) 397 (31%) <.0001
 Prosthetic pathology 50 (7%) 119 (9%) .08
Previous SVD episode 16 (2%) 38 (3%) .3
Stenosis 170 (24%) 405 (31%) <.001
Incompetence 198 (28%) 494 (38%) <.0001
Moderate stenosis and incompetence 345 (48%) 382 (10%) <.0001
Sinus rhythm 276 (39%) 907 (70%) <.0001
Atrial fibrillation or flutter 433 (61%) 343 (27%) <.0001
Pacemaker 4 (0.6%) 29 (2%) .005
Coronary artery disease 28 (4%) 343 (25%) <.0001
Critical coronary disease 18 (2%) 273 (21%) <.0001
Coronary artery bypass graft 24 (3%) 317 (25%) <.0001
Ascending aorta replacement 14 (2%) 110 (8.5%) <.0001
Crossclamp time (min) 45.2 ± 19.2 79.1 ± 29.5 <.0001
Cardiopulmonary bypass time (min) 72 ± 32.6 112 ± 40.8 <.0001

NYHA, New York Heart Association.