Are allografts the biologic valve of choice for aortic valve replacement in nonelderly patients? Comparison of explantation for structural valve deterioration of allograft and pericardial prostheses

Freedom from explantation for structural valve deterioration (SVD) of stented bovine pericardial bioprostheses (open circles) and allografts (closed circles) used for aortic valve replacement. Vertical bars are asymmetric 68% confidence limits equivalent to 1 SE. A, Patients 50 years of age and younger at valve replacement. There were 406 patients with allografts experiencing 19 events (186 and 32 at risk at 5 and 10 years) and 51 patients with pericardial bioprostheses experiencing 23 events (43 and 29 at risk at 5 and 10 years; P = .5). B, Patients >50 to 60 years of age at valve replacement. Three patients whose indication for pericardial prosthesis explantation could not be determined were excluded. There were 203 patients with allografts experiencing 7 events (103 and 20 at risk at 5 and 10 years) and 84 patients with pericardial bioprostheses experiencing 24 events (67 and 46 at risk at 5 and 10 years; P = .7). C, Patients 60 years and older at valve replacement. There were 135 patients with allografts experiencing 1 event (70 and 8 at risk at 5 and 10 years) and 340 patients with pericardial bioprostheses experiencing 23 events (254 and 131 at risk at 5 and 10 years; P = .9).

Freedom from explantation for structural valve deterioration of stented bovine pericardial bioprostheses (open circles) and allografts (closed circles) used for aortic valve replacement in propensity-matched patients. Vertical bars are asymmetric 68% confidence limits equivalent to 1 SE.

Explantation for structural valve deterioration (SVD) of stented bovine pericardial bioprostheses and allografts used for aortic valve replacement. A, Freedom from explantation for SVD. Symbols represent each event, positioned according to the Kaplan-Meier method; open circles represent the pericardial group, and open squares, the allograft group. Vertical bars are asymmetric confidence limits equivalent to 1 SE. Numbers in parentheses are the number of traced patients. Solid lines are parametric estimates enclosed within dashed confidence limits equivalent to 1 SE. B, Instantaneous risk of explantation for SVD (hazard function). The model formed for allografts consisted of a constant hazard phase (0.35% per year) and a late rising hazard phase of Weibull shape (hazard = 1.6 × 10⁻⁶t^4.6, where t = time in years since implantation); that for pericardial prostheses consisted of a Weibul late phase (hazard = 1.4 × 10^×5t^3.7).

Freedom from explantation for structural valve deterioration (SVD) according to age at implantation. Equations from separate hazard functions for each type of prosthesis (Table 3) were solved for 4 specific ages at index operation. Solid lines are parametric estimates enclosed within dashed confidence limits equivalent to 1 SE. A, Age 40 years. B, Age 50 years. C, Age 60 years.

Probability of explantation for structural valve deterioration (SVD) by 12 years as a function of age at implantation. Equations from separate hazard functions for each type of valve (Table 3) were solved at 12 years as a continuous function of age at index operation. Solid lines are point estimates. Wide dashed lines are confidence limits for allograft estimates, and fine dashed lines are those for pericardial prostheses.