Statistical Analysis
Pre-operative and post-operative echocardiography were compared using
the 2-tailed paired t test for peak transvalvular gradient across
the AV. Statistical significance was set at P < 0.05. Overall
freedom from reoperation was determine by Kaplan-Meier analysis and is
expressed as the percentage of patients who remained event free. If
patients had multiple re-operations, the number of days to the first
re-operation was used for the analysis. If patients had no listed
re-operations, it was assumed that the material was alive at the date of
censorship.