Survival after stentless and stented xenograft aortic valve replacement: a concurrent, case-match trial.

Background. In order to compare the long-term outcome of stented vs stentless aortic xenografts, a non-randomized, concurrent case-match trial was conducted on all consecutive patients operated between January 1992 and April 2000. Methods. Two hundred and ninety-two patients had stented (group 1) and 376 stentless (group 2) xenograft aortic valve replacement (AVR). Group 1 patients were older (75.0 ± 4.1 vs 70.4 ± 6.7 years, p = 0.01), while male gender and aortic stenosis were equally prevalent. NYHA functional class III-IV (85 vs 78%, p = 0.03) and associated procedures (53 vs 41%, p = 0.01) were more common in group 1. The aortic cross-clamping (79.7 ± 27.8 vs 96.1 ± 23.3, p = 0.001) and bypass (91.4 ± 57.5 vs 128.5 ± 34.0, p = 0.002) times were shorter in group 1. A case-match analysis identified 113 identical patient pairs, on the basis of age, gender, diagnosis, NYHA class, associated cardiac disease, and valve size. Results. The early mortality was higher in group 1 (5.3 vs 2.7%, p = 0.3), though not significantly. During follow-up (37 ± 30 vs 43 ± 35 months, p = 0.6), 26 late deaths were recorded (10.3 vs 13.6%, p = 0.4). The 8-year survival was comparable (76 ± 7 vs 75 ± 5%, p = 0.2), but freedom from cardiac (77 ± 7 vs 90 ± 4%, p = 0.02) and from valve-related death (78 ± 7 vs 91 ± 4%, p = 0.02) was higher in group 2. Freedom from structural deterioration (99 ± 1 vs 98 ± 2%, p = 0.7) and from reoperation (99 ± 1 vs 95 ± 3%, p = 0.2) at 8 years was similar. The late functional status was equally satisfactory (NYHA class I-II 92.7 vs 94.7%, p = 0.06). Conclusions. The survival free from cardiac and valve-related mortality when stentless xenografts for AVR are used is superior to that achieved with stented grafts. Stentless AVR has the potential of conferring selective survival advantages late after operation.