Data Analysis

Analysis was performed according to a predefined statistical plan. Primary analysis was ITT. A per protocol (PP) analysis was also performed, which excluded patients not meeting inclusion criteria for any reason including failure to confirm diagnosis of dissection on central imaging review. Exact confidence intervals for proportions with events were calculated using the binomial (Clopper-Pearson) exact method. The treatment effect of AP vs AC was tested using exact logistic regression. Analysis was performed using SPSS Statistics, version 20 (IBM) and for exact logistic regression in Stata statistical software (StataCorp). The P value level of significance was less than .05, and P values were 2-sided.